Showing posts with label Pharmacology. Show all posts
Showing posts with label Pharmacology. Show all posts

Wednesday, February 29, 2012

Psychiatric Disorders and Pharmacology

Mood Disorders 
Major Depression (MD)
  • Theories of Cause 
      1. o Genetic: Genes play role but must interact w/environment to develop MD 
      2. o Biochemical: Initially thought path dysfunction of serotonin (regs sleep, appetite, libido) and norepi (energy, pleasure, concentration) cause; But prob also i/c dopamine, Ach, Gaba; Also probably not sole cause 
      3. o Hormonal regulation: Hypo-Pit-Adrenal path malfunction →↑ cortisol which is often high in depressed pts 
      4. o Circadian rhythm: Most pts w/MD have loss of deep and REM sleep 
      5. o Psychodynamic: Stressors and events trigger episode if vulnerable 
      6. o Cognitive: Experience teaches negative thoughts which depression; Three learned thoughts responsible: 1) Negative self view, 2) Pessimistic view of world, 3) No hope for future 
      7. o Learned Helplessness: Normal anxiety is replaced by depression as person learns they have no control over situations; Popular modern theory that believes remedy is teaching coping skills and self confidence (i.e. groups) 
  • Facts: *Pt presents w/history of one or more major depressive events and NO manic/hypomanic episodes; *s/s represent a change in usual behavior (slight difference from dysthymia); *Usually have more than one episode in life; *Not verbally mediated; *One episode means meds for life 
  • DX: 5 or more of following occur daily for 2 wks: 1) Depressed mood most of day, 2) Anhedonia, 3) Wt loss (5% in month), 4) Insomnia/hypersomnia, 5) or motor activity, 6) Anergia, 7) Feel worthless or guilty, 8) indecisive or concentration, 9) Death/suicide thoughts 
  • Subtypes: MD may include following features: Psychotic (halluc/delusions), Catatonic (echo, strange movement), Melancholic (wt, early morn wake), Postpartum onset (4 wks PP), Seasonal (winter), Atypical (wt, oversleep) 
  • NX: Severe vegetative (∆ in activity necessary to support life) s/s include: severe wt, psychomotor retard, early morn waking, libido; Main NX DX suicide risk after few days on meds during cycle out, coping, self carev Monitor sleep, wt/eating, bowel movements; Expect withdrawn behavior; Usual TX for MD is Cognitive behavior therapy and ECT (NPO 6hr prior; remove contacts, dentures; Give premeds 30 min prior)
Dysthymia
  • Facts: S/S represent usual behavior for 2 yrs; Less severe low, verbal mediate 
  • DX: 2 or more of: 1) or appetite (often ), 2) or sleep, 3) Anergia, 4)self-esteem, 5) Poor concentration/decision making, 6) hopelessness 
Bipolar Disorders
  • Facts: Chronic, recurrent shifts in mood, energy, and functioning; Severe mortality w/highest suicide rate of all Psych illnesses; Often starts at 20 yrs; Probable genetic influence as bipolar pts often have bipolar relatives 
  • Type 1: At least one Manic episode alternating with MD 
  • Type 2: At least one Hypomanic episode alternating with MD (often OCD) 
  • Cyclothymia: Hypomanic episode alternates with minor depression (2 yrs) 
  • Psychotic: Severely impaired mental state w/hallucination, delusion, and/or personality ∆, w/disorganized thought and loss of touch w/reality; Emergency! 
  • Mania: impairment in activity/relationships; TX needed to avoid harm to self/others; Psychotic features; S/S not due to drugs/disease 
  • Hypomania: ∆ in functioning/mood that is not ordinary for pt and can be observed by others, no impairment socially, S/S not due to drugs/disease, TX not an emergency 
  • Bipolar DX: Distinct abnormal/persistent in mood for 4 d (hypo) or 1 wk (mania), AND 3 or more of: 1) Grandiosity, 2) need for sleep (rested w/3 hrs), 3) need to be talkative, 4) Flight of ideas, 5) Distractible, 6) goal-directed activity, 7) need for unhealthy living ( spending, sex) 
  • Bipolar episodes: Mixed ( and daily for 1 wk); Rapid Cycling (4 or more episodes in 1 yr); Regular (at least 1 manic episode w/depression) 
  • Mental Status Exam: Depending upon manic () vs depressed () will show: Appearance ( bizarre dress, frequent ∆; poor hygiene); Speech ( flight of ideas, rapid; retarded); Thought ( grandiose, distracted; hope/helpless); Affect ( labile; flat/dull); Psychomotor ( hyper; retarded); Delusions ( grandeur, bizarre; negative triad); Hallucinations (any in both states) 
  • NX: Don’t let make big decision when or ; Extreme risk of self harm; Electroconvulsive therapy possible (for psychotic depression); Sleep therapy; Distractibility can be used positively during interventions; environmental stimulus (such as neutral colored rooms, coordinated accessories) 
Mood Disorder Pharmacology 
Antidepressants (MD pts)
  • Facts: All but MAOI block reuptake of serotonin and sometimes norepi making more available in synapse ( mood, alert, concentration); Can be given once a day, but often has 3-4 wk time to therapeutic effectiveness 
  • Indications for use: Recurrent depression, Psychomotor retardation, Depression w/no clear cause, Family Hx, Chronic pain, Eneuresis 
  • Types 
    • Benzodiazepines
      • Alprazolan (Zanax): Short term only as dose needed over time
    • SSRI (selective serotonin reuptake inhibitor) 
      • SSRI S/E: Sexual depression/dysfunction, N/V/D, insomnia, anxiety, dry mouth, tremor, fatigue, H/A, toxic s/e rare 
      • NX: Never take w/MAOIs, Liver/renal/CBC test, d/c meds slow 
      • Fluoxetine (Prozac): sedation, S/E
      • Sertraline (Zoloft): toxicity in OD, S/E, halflife than Prozac 
      • Paroxetine (Paxil): Safest for elderly, Lowest halflife 
      • Fluvoxamine (Luvox) ƒ Citalopram (Celexa
      • Escitalopram oxalate (Lexapro)
    • SNRIs (Serotonin/Norepinephrine reuptake inhibitor) 
      • Pros: sex probs, insomnia, response quicker, anxiolytic like 
      • Cons: BP, Sedating, Anticholinergic s/e (constipation, sweat) 
      • Effexor (Venlafaxine): S/E: dizziness, migraine, wt gain 
      • Serzone 
      • Trazodone (Desyrel
      • Remeron: S/E: somnolence, dizzi, wt gain; Adverse: agranulocytosis, neutropenis; NX: some respond well only to this
    • Norepi/dopamine agonist 
      • Facts: Stimulant inhibits reuptake and release of Norepi/dopa 
      • Cons: seizure risk ƒ Bupropion HCl (Wellbutrin): No effect on serotonin/ MAO 
    • Tricyclics (Norepi/serotonin reuptake inhibitor + minor Ach/Hista effect 
      • Examples: Imapramine (Tofranil), Desipramine (Norpramine, Pertofrane), Amitriptyline (Elavil, Endep), Nortriptyline (Pamelor, Aventyl), Protriptyline (Vivactil), Doxepin (Sinequan)
      • S/E: Anticholinergic effects (dry mouth, constipation, urinary hesitant/retention, sweating, drowsiness, blurred vision); EPS Cardiovascular (postural BP, HR, heart conduction probs); Glaucoma worsened, Toxic confusion/psychosis; Wt gain, SZ,
      • Overdose: 1000-4000 mg can be Fatal
    • MAOIs 
      • Facts: Monoamine (epi, norepi, sero, dopa) oxidase responsible for destroying excess/used MAs; Inhibiting enzyme level of all 
      • Types: Phenelzine (Nardil), Isocarboxazide (Marplan), Tranylcypromine (Parnate)
      • CX!: Some foods contain MAs (tyramine) which if not metabolized in liver causes ↑↑ HT and CVA; Foods include aged cheese, chicken liver, beer, red wine, chocolate, cold/sinus meds, diet pills; Avoid certain restaurants (Chinese); 1o s/s is severe h/a
      • S/E: BP most critical; Orthostatic BP, dizziness, appetite 
      • Key: BP is toxic effect (wrong food); BP is med caused S/E
    • Psychostimulants 
      • Facts: Meds such as Ritalin, Dexedrine, Adderall, and Cylert can be used sparingly in depression; Block reuptake and production 


Mood Stabilizers (Bipolar 1 pts)
    • Lithium 
      1. Facts: Used in psychiatric disorders non-responsive to other meds; Blood level of 0.1-1.5 key as toxic death possible. Higher only w/psychosis; Must maintain adequate salt in diet (consistent level, not too or
      2. Indications: Acute Mania, Bipolar prophylaxis 
      3. Possible use: Bulimia, Alcohol abuse, Schizoaffective (mania or depression with schizo like delusions/hallucinations/etc) 
      4. Method of action: Replaces Na+ in many neurons but creates different resting potential, limiting speed of nerve impulse = mania/hyperactive 
      5. S/E: Major risk of hypothyroidism and urine concentration probs; Parkinson like, cog wheeling, sluggish, forgetful; Chronic N/V/D so take w/food; Wt gain, Polydypsia, Polyuria, Allergic rash w/capsules 
      6. C/I: Never take with diuretics or Anticholinergic meds 
      7. Causes of toxic levels: Na intake (more room for Li); Sweating, Illness 
    • Anticonvulsants 
      • Carbamazepine (Tegratol): Used when no response to Lithium; Better for rapid cycle Bipolar; Blood levels at 6-8 mg/l
        • S/E: Sedation, Mal coordinated, agranulocytosis, aplastic anemia so NX: monitor CBC and alert for fever/sore throat; birth defects
      • Valproate (Depakene, Depakote): Used w/manic or schizoaffective; Blood levels at 50 mg/l
        • S/E: Severe/Fatal Hepatotoxicity, platelets, neural tube defects
      • Clonazepam (Klonopin): Benzo for acute mania, acute help while waiting for Lithium effects to occur ƒ S/E: Sedation, Anoxia, Disinhibition effect
Schizophrenia 
Facts: Psychotic Disorder (other PDs are schizoaffective, delusional, induced psychosis); Drug abuse (50%), nicotine addiction (90%) common; cause of death is suicide
Theories: Dopamine, Serotonin, and Norepi elevation is suspected but no concrete proof exists; Genetics plays role (45% chance with schizo twin or schizo parents) and with environmental factors is possible cause; MRI shows enlarged ventricles
4 steps to DX: (must meet all 4 for schizo dx)
  • Characteristic S/S, active phase: 2 or more of following in 1 month period: 1) Delusions, 2) Hallucinations, 3) Unorganized speech, 4) Catatonic behavior 5) Negative symptoms 
  • IF: (bizarre delusions or auditory hallucinations) AND (continuous voices or multiple voices) is enough to satisfy first step 
  • Social Dysfunction: Marked decline in social abilities (work, relations, self-care, etc) or failure to achieve expected level in adolescence 
  • Duration: Continuous s/s for 6 months w/at least 1 month of active phase s/s 
  • Rule Outs: Other mental diseases and medical conditions have been r/o; If pt has developmental disorder then must present w/ prominent hallucinations or delusions for 1 month for schizo dx 
Symptom Groups (which ones are present varies between individuals)
    • Positive
      1. Acute onset, Normal CT/neuro tests, Good response to antipsychotic meds 
      2. Types: Hallucinations, Delusions, Unorganized speech, bizarre behavior, Ideas of reference delusions (others are plotting against me) 
    • Negative
      1. Insidious onset, CT shows atrophy, abnormal neuropsychological tests, Poor response to antipsych meds, More destructive than positive s/s 
      2. Types: Blunt affect, Poverty of thought (alogia), motivation (avolition), Inability to experience pleasure (anhedonia) 
    • Cognitive: Inattentive, Distractible, Poor memory/problem solving/decisions, Illogical thinking, Impaired judgement, Can’t name familiar objects 
    • Mood: Dysphoria, Suicidal, Hopelessness 
Subtypes: Paranoid, Catatonic, Disorganized, Undifferentiated, Residual
Course of Disease: Prodromal s/s may appear up to 1 yr prior to first psychotic break
and include withdrawal, lonely, depressed, unrealistic future plans; Early phase s/s include anxiety, phobias, obsessions, compulsions, concentration/schoolwork probs 
NX: For auditory hallucinations, pt should tell voices to go away; for poisoning suspicion the nurse can taste food in pts presence,
Schizophrenia Pharmacology 
Facts
  • Inhibit neurotransmitters dopa, serotonin, norepi, histamine to psychosis 
  • S/E: Dop antagonist (parkinsonism, akinesia, akathisia, dyskinesia; (↑prolactin/amen/galactorhea) ACH antag (Blurred Vision, dry mouth, constipation, urinary hesitancy) Norepi antag (orthostatic hypotension, ejaculation probs) Hist antag (wt gain, sedate); Atropine Psychosis (Dry, Fever, Confused, Diplopia)
Atypical Antipsychotics:
  • Facts: Target (+) and (-) schizo signs w/few S/E b/c Dop antag only in limbic 
  • Olanzapine: S/E wt gain, CHO, DM 2 (best at improving cognition) 
  • Clozapine (Clozaril) S/E can be WBC so NX CBC weekly for 6mos; S/E: sedation, salivate, tachycard, dizzi; b/c of effects NOT 1st CHOICE 
  • Risperidone (Risperdol) Does not WBC but at dose just above normal causes motor probs; S/E: Sedates, orthohypo, wt gain, sex probs, CVAs; Only Atypical available in Depot Form (oil based time released SQ) 
  • Quetiapine (Seroquel) Broad antagonist especially Norepi/Hist (see S/E in 1st gen); Very few extrapyramidal symptoms (movement probs) 
  • Ziprasidone/Geodon (sero/norepi reuptake inhibitor; s/e BP, QT interval so fatal with arrhythmias, EKG and K/Mg test prior to Rx) 
  • Aripiprazole/Abilify ( dopa levels where high and dopa levels where low, s/e sedate, BP, anticholinergic) 
Traditional Antipsychotics
  • Facts: Pros: Cheap, Depot form (oil based time released SQ) Cons:Dopa receptor block in limbic/motor areas which can cause severe EPS s/e! 
    • EPS: extrapyramidal s/s: Akisthesia (restless feet), Dystonia (muscle spasm), Akinesia (heavy limbs), Parkinson like, Tardive dyskinesia (face muscle spasms) 
    • o Anti-EPS: Common meds for EPS tx are Benadryl, Cogentin, Artane
    • Common Types (Phenothiazines except Haldol, a Butyrophene) 
      • Haloperidol (Haldol): sedation, doses used to aggressive behavior,  risk of EPS, hallucinations, hypotension risk, used w/elderly
      • Chlorpromazine (Thorazine): sedation, hypotension risk, EPS risk 
      • Thiorizidine (Mellaril): Severe ECG ∆s, sudden death, Last resort med 
      • Trifluoperazine (Stelazine): low sedation, used with withdrawal/paranoia 
      • Fluphenazine (Prolixin): Very little sedation 

Thursday, May 22, 2008

Cardiovascular Drugs made EZ: Part 2

One subject that often confuses nursing students preparing for the NCLEX exam and practitioners alike, is that of clotting and anticoagulants. The problem with this, is these medications are extremely common in both inpatient and outpatient populations, so this knowledge is imperative for those in the healthcare industry to have. Lets take a look together and see if we can make it a bit more simple, in case your NCLEX exam decides to drill you on this point. We will go step by step through the clotting process, taking small sidetracks to look at specific medications.

Hemostasis

• When vascular injury occurs, various mechanisms are available to stop the loss of blood
• The mechanism employed depends upon the extent of injury, but the end result of all is to produce strands of Fibrin to patch the hole; The difference in the various mechanisms is the speed and amount of Fibrin produced
1.Platelet Plug
2.Intrinsic Coagulation
3.Extrinsic Coagulation


Platelet Plug

When vascular endothelial tissue is damaged, a platelet plug can form, sealing the hole. If no deeper tissues are exposed, this may be the extent of the healing process. If damage is more extensive, platelets, as well as tissue exposure can initiate further coagulation. Platelet plug formation occurs in 4 steps (use pic to right of text as visual guide):



1) Adhesion: When subendothelial tissue is exposed, sticky proteins (Von Willebrand factor) are exposed to passing blood and act as magnets to passing platelets.

2) Aggregation: ADP, a breakdown product of ATP released from damaged cells, stimulates the production of receptors (GPIIb) on the platelets that bind a free floating soluble protein Fibrinogen.

Pharm Note: Plavix and Ticlid inhibit ADP, so platelets are not stimulated to produce fibrinogen receptors and clots are more difficult to produce
Pharm Note: Abciximab (Reopro) binds to the platelet GPIIb receptor and blocks fibrinogen from binding, and clots are more difficult to make





3) Secretion: Stimulated platelets release chemicals like Thromboxane, that attracts other platelets. Fibrinogen can bind two platelets, thus platelets begin to collect in mass.

4) Platelet Coagulation: Stimulated platelets now produce factor V, which leads to fibrinogen being transformed into Fibrin threads to incase the aggregated platelets

Pharm Note: Aspirin blocks the release of Thromboxane for the life of the platelet, so cell aggregation is made difficult. This is why aspirin is known to make platelets less sticky, and is so frequently given as prophylaxis against clot formation. Since platelets are still allowed to bind Von Willebrand, there is still some platelet plug action, meaning some bleeding is stopped. This is why Aspirin is not as powerful an antiplatelet drug as prescription drugs like Plavix and Reopro.


(platelet aggregation)


(fibrin threads creating plug)

Intrinsic Coagulation
When the insult is deeper, collagen may be exposed, initiating the intrinsic coagulation cascade. Collagen activates factor 12 then 11 then 8 + 9 then 10. 10 converts Prothrombin into Thrombin, which then converts Fibrinogen to Fibrin. This process is faster than a platelet plug as you don’t need to wait for platelets to collect, and it forms more extensive Fibrin patches.

Pharm Note: Heparin inhibits the Intrinsic Factors, making them slower to respond, which makes clotting more difficult and less extensive
Lab Note: Partial Thromboplastin Time (PTT) measures the speed of collection of these factors, thereby measuring the effectiveness of Heparin. PTT, usually 30-40 seconds is the amount of time it takes all of the necessary factors to gather at site of need. Heparin binds these factors, slowing their collection, and lengthening PTT.

Extrinsic Coagulation
When deep injury occurs, tissue is exposed to blood, initiating the extrinsic coagulation cascade. Tissue factor activates factor 7 then 10. 10 then follows same route as above. With fewer steps this cascade is faster than the intrinsic and develops more extensive Fibrin patch. Of importance to note is just as Ca makes muscle contract stronger, its presence also makes clots stronger.

Pharm Note: Factor 7 is made in the liver from Vitamin K. Warfarin (Coumadin) blocks Vitamin K and thereby reduces the amount of Factor 7 made. Now it takes longer to collect enough Factor 7 to initiate this extrinsic clotting, and you have slower clotting that is less extensive. Since the medication effects future Factor 7 production and not that currently present in the blood, it takes a few days to see its effects.
Lab Note: Prothrombin Time (PT) measures the speed of collection of Factor 7, thereby measuring the effectiveness of Coumadin therapy. This value is converted to the INR. Think of this value as a stopwatch that starts timing as soon as injury occurs. PT, usually 10-12 seconds is the amount of time it takes factor 7 to reach the area of need.
(extensive fibrin patch)
Regulation of Coagulation
To assure coagulation does not go too far, 2 specific mechanisms inhibit or reverse the process:
1) Antithrombin III (AT III): AT III inhibits the production of Thrombin by blocking Prothrombin, thereby reducing the amount of Fibrin formed. Healthy endothelial cells produce this, thereby quarantining off the damaged area so clotting does not extend beyond where it is needed.
Pharm Note: Lovenox (Enoxaparin) enhances the activity of AT III, thereby slowing clot formation. The low molecular portion of heparin is the active part here, so regular Heparin partially works here in addition to Intrinsic factor inhibition.
Lab Note: Partial Thromboplastin Time (PTT) is not effected by Low Molecular weight heparins (Lovenox) because no Intrinsic factors are inhibited.
2) Tissue Plasminogen Activator (TPA): Injured cells also release TPA, which converts free floating Plasminogen to Plasmin. Plasmin degrades Fibrin, so clots are constantly broken down, even as they are built. The more active system wins, depending upon how much clotting is actually needed.
Pharm Note: TPA (Alteplase) can be synthetically injected to actively break down clots, such as in the case of a Stroke or Myocardial Infarction. Great caution should be used when administering this as massive, even fatal bleeds are possible. (Streptokinase and Urokinase are alternatives that work by same method)

Thursday, May 15, 2008

Cardiovascular Drugs Made EZ: Part 1

Pharmacology is a key subject when studying for any healthcare board exam, such as the NCLEX or USMLE. This word can be a simple stimulus for nightmares in many in nursing or medical school studying for their boards. We are going to take a multi-part look at this subject by looking at one of the biggest classes of drugs that you will need to know: Drugs effecting the heart and vasculature.


This is a huge class of drugs, accounting for a huge chunk of the drugs that we actually need to know well, and is one that the NCLEX and USMLE are going to ask you about. Lets break this class down into smaller, more manageable chunks. We will start with drugs used to treat Hypertension, as this class is very large and very important. First of all, take a look at the picture below for a summary of the drugs we will discuss.





ACE Inhibitors

Names:
• “Prils” Think an ACE is a Pro (kinda like a pril)
• Examples: Enalapril (Vasotec), Captopril, Lisinopril
Uses:
• Hypertension, Heart Failure, Protection for diabetics vs nephropathy, Decrease Mortality in post-MI patients due to afterload reduction
Action:
• blocks the enzyme that converts angio I to angio II in the lungs. Angio II leads to vasoconstriction, aldosterone release, and sodium retention: this is blocked, which decreases blood pressure and puts less strain on heart
Common Side Effects:
Dry hacking cough; Angioedema; Hyperkalemia
• Taste disturbance; Rash; Insomnia, Orthostasis
Nursing Implications:
• CI: Pregnancy Category D; Bilateral Renal Stenosis
• Use K supplements carefully due to hyperkalemia concerns
Stop drug if cough, angioedema
• Taste of food may be diminished during first month of therapy


Angiotensin Receptor Blockers (ARBs)
Names:
• “Sartans”
• Examples: Losartan (Cozaar), Irbesartan, Valsartan (Diovan)
Uses:
Hypertension, Heart Failure
Action:
• Blocks the receptor for Angiotensin II, blocking the effects of this potent vasoconstrictor
Common Side Effects:
• Hyperkalemia, Angioedema, Orthostatic hypotension
Nursing Implications:
• CI: Pregnancy Category D in 2nd/3rd trimesters; Bilateral Renal Stenosis
• Safer side effect profile than ACE inhibitors but less studied



To understand ACE and ARB it is vital that you have an idea of what the Renin-Angiotensin-Aldosterone System (RAAS) is. Remember the purpose of RAAS is to increase blood pressure in response to decreased renal blood flow or pressure, and the purpose of the drugs that work here is to block this system and lower blood pressure. Check out the pick below for a summary of the RAAS and where certain drugs work.




Beta Blockers (or beta antagonists)

Names:
• “OlOls: Remember Beta video tapes? They are OLdOLd
• Ex: Selective B1: Metoprolol, Atenolol (I MET A TEN last night)
• Ex: B1B2: Propanolol (Inderal), Labetalol, Carvedilol (Coreg) (ilol, alol-also alpha blocker)
Uses:
Hypertension, Angina, Arrhythmias, Glaucoma, MI prophy, Migraines
Action:
• Block adrenergic Beta receptors (1 heart, 2 lungs), leading to lower sympathetic activity = decrease in cardiac output, blood pressure and renin activity. Also some drugs lower aqueous humor production
Common Side Effects:
Bradycardia, fatigue, insomnia, bizzare dreams, sex dysfunction, lipid dysfunction; Respiratory distress (wheezing), Agranulocytosis, depression
Nursing Implications:
C/I in asthma, bradycardia, severe renal/hepatic disease, hyperthyroid, CVA
Signs of hypoglycemia (DM), tachycardia (hyperthyroid) may be masked
Glucagon may reverse overdose


Calcium Channel Blockers (Antagonists)

Names:
• Dihydropyridines: “Pines”: Amlodipine (Norvasc), Nifedipine (Procardia)
• Non-Dihydropines: Diltiazem (Cardizem), Verapamil
Uses:
Angina, Arrhythmias (Non-D’s have more AV node effect)
Hypertension (Dihydro’s have more vasodilation effect)
HT (Pines), Dysrhythmias (Verapamil), HT/Dys (Diltiazem)
Action:
• Blockade of Ca channels causes arteries to relax (vasodilate) and cardiac conduction to slow through the AV node
Common Side Effects:
All: H/A, hypotension, dizziness, peripheral edema, Renal/Hepatic dysfunction
Dihydros: Ankle edema, flushing, tachycardia, gingival hyperplasia
Non-D’s: AV block, bradycardia, worsened systolic dysfunction
Nursing Implications:
Use very cautiously with heart failure/left ventricle inpairment, AV block
Don’t abruptly stop medication; Warn patient to contact MD if irregular HR, SOB, swelling, pronounced dizziness, constipation, nausea, hypotension


Peripheral Alpha Blockers

Names:
• Mixed names: “Zosins” for BPH, “ilol” for HT;
• Examples: Carvedilol (Coreg), Tamulosin (Flomax), Prazosin (Minipress)
Uses:
Hypertension, Peripheral Vascular Dz (raynaulds, phlebitis, etc), BPH
Action:
• Blockade of Alpha 1 relaxes smooth muscle in arteries and prostate capsule, leading to lower blood pressure, reduction in BPH, and increased blood in tissues (warm/pink skin) as well as Renal arteries
Common Side Effects:
Orthostatic Hypotension (especially first dose), Reflex Tachycardia, Ejaculation problems, nasal congestion
Nursing Implications:
• Begin with small dose and give at bedtime to avoid dizziness and syncope
Change positions slowly to decrease orthostatic hypotension
Alcohol, Excessive exercise, prolonged standing, heat make S/E worse

Central Alpha Blockers

Names:
Clonidine (Catapres); Methyldopa (Aldomet)
Uses:
Hypertension
Action:
• Central acting sympatholytic stimulates pre-synaptic alpha receptors to release NE, which paradoxically reduces peripheral NE release, inhibiting vasoconstriction = vasodilation and lower BP
Common Side Effects:
• Sodium/Water retention, Dry mouth, Bradycardia, Impotence, Depression
Nursing Implications:
Advise patient not to abruptly withdrawal because significant rebound hypertension can result
C/I in impaired liver function so monitor liver function tests occasionally
Do not confuse with the benzo Klonipin (patients have done so and taken a bunch of Clonidine for a high, only to end up with a real low…BP that is.


Diuretics

Types:
Loop: Furosemide (Lasix), Bumetanide (Bumex), Torsemide (Demadex)
Thiazide: Hydrochlorothiazide (HCTZ)
K-sparing: Amiloride, Spironolactone
Carbonic Anhydrase Inhibitors: Acetazolamide (Diamox)
Uses: Edema associated with heart failure; Ascites with Cirrhosis; Hypertension
Action:
Loop: Inhibit Na, Cl, and H2O resorption in the loop of henle thus decreasing blood volume; Also increase the excretion of K; Potent diuretics
Administer IV Lasix slowly because hearing loss can occur if given rapidly
Thiazide: Inhibit Na resorption and increase Cl, H2O, K, Ca, Bicarb, Mg excretion in the urine; Also cause arterial dilatation; Moderate diuretic
• While K and Na may be excreted, HyperCa is more likely to develop so never administer to patient with hypercalcemia;
• Eat foods rich in potassium, use sunscreen, and change position slowly
Caution when taking with Lithium, Digoxin, Corts, PO Diabetic meds
K-sparing: Block Na-K exchange in distal tubule causing loss of Na and water and retention of K; Weak diuretic mostly added to preserve K
C/I in severe renal/hepatic dysfunction, hyperkalemia, Current ACE-I use
Carbonic anhydrase inhibitors:
Used to treat M.Alkalosis, Open Angle Glaucoma, Epilepsy, High altitude sickness
• Inhibits the enzyme carbonic anhydrase which normally is responsible for excreting H to combine with HCO3 for elimination of excess acidity, as well as promoting diuresis. This drug obviously leads to an increase level of H+ in the blood (M.Acidosis) and an increased excretion of Bicarb (HCO3)
C/I with CLOSED (narrow) angle Glaucoma
S/E i/c Renal Calculi, Hypercalcemia, and Hemolytic anemia
Common Side Effects:
Loop/Thiazides: Hypokalemia, Hyperuricemia, Glucose intolerance, sexual dysfunction, increase cholesterol/triglyceride levels
K-Sparing: Hyperkalemia especially when used with ACE inhibitors
Nursing Implications:
• Caution for electrolyte disturbances; Watch for cramping, paresthesia
Administer in morning to avoid diuresis during night, Supplements (PhosLo)

Saturday, April 12, 2008

Antibiotics made EZ...Part 2

If you have been studying for your NCLEX or USMLE examination for a while, you may have noticed there is some confusion about antibiotics. OK, hopefully you had a chance to read through the Antibiotics made EZ, Part 1. If you havn't, it may be better for you to jump down and read about the bugs, before we dive into the drugs. One of our worst mistakes in the vietnam war, was going into a country completely ignorant of our enemy. We took the wrong guns, and the wrong equipment, and paid for it. Same thing goes here. If you don't know the bugs, reading about the drugs listed below, will make little sense.

That being said, lets take a look at some of the most common medications used to treat Bacterial infections. NOTE that this is empiric therapy only...meaning these are the best options for treatment, BEFORE, our culture and sensitivity comes back. Once those results are ready, they should guide what we use. Also, the spectrum of resistance may be different wherever you live, so these are general recommendations on the most popular drugs. Ok that being said, lets take a look at the first and largest group...the Beta Lactams

Beta Lactams: the Penicillins

Penicillins (PCNs)
MOA: All Beta Lactams are Bactericidal, inhibiting cell wall synthesis; Preg Cat B

Natural Penicillins
Spectrum: G(+): Strep, Bacillus, Clostridium; G(-): Neisseria
Facts: Relatively few side effects; Allergic reactions relatively common; 98% of Staph are resistant to PCN due to enzyme able to destroy medication (PCNase)
PCN G: IV, IM (often only 1 injection need, i.e. Syphillis)
PCN V: PO, poorly absorbed so only for minor infections

Penicillinase (PCNase) Resistant PCNs
Spectrum: G(+): Staph (only indication though spectrum similar to PCN)
Facts: Original Drug was Methicillin but caused too much Interstitial Nephritis and was withdrawn; Despite this, Staph resistant to this class was termed Methicillin resistant (MRSA or MRSE)Oxacillin (PO, IV); Cloxacillin & Dicloxacillin (PO); Nafcillin (IV)

Aminopenicillins
Spectrum: G(+): Same as PCN plus Enterococcus plus G(-): Moraxella, E.Coli, Salmonella, H.influenzae, H.Pylori;Facts: NH3 group makes enhanced activity against G(-); 2nd most common cause of C.Dif Colitis Amoxicillin: PO; ENT infections, Cellulitis, Gonorrhea, C.A.Pneumonia (Strep)
Ampicillin: IV; Listeria, Enterococcus

Extended Spectrum PCNs
Spectrum: Same as AminoPCNs plus G(-): Pseudomonas, Proteus, Bacteroides
Facts: Broad Spectrum, usually reserved for serious infections with susceptible bacteria; No PCNase resistance when given alone; Often combo w/Aminoglycoside for Pseudomonas
Ticarcillin (IV); Piperacillin alone withdrawn (Combination drug Zosyn still available)

PCN/Beta Lactamase Inhibitor Combinations

Facts: PCNase inhibitor added to a Beta Lactam to extend coverage, mainly against S.aureus
Unasyn: Ampicillin + PCNase inhibitor
Augmentin: Amoxicillin + PCNase inhibitor
Zosyn: Piperacillin + PCNase inhibitor (Very Broad Spectrum)

Beta Lactams: the Cephalosporins
Class Facts:
Similar to PCN in most ways, but only 5-10% of PCN allergic will be allergic to Cephs
Generally avoided only if history of Anaphylaxis with PCN
Generally do not cover Anaerobes, Pseudomonas or cross BBB unless indicated
Do not cover MRSA (except Ceftaroline) or Enterococcus
Preg Cat B; Do not take with Alcohol; Consume at least 3 L water daily; Take w/food (avoid GI probs)
All Cephs can cause ↑PT/INR (give Vit K) and C.Dif Colitis

1st GenerationSpectrum: Broad G (+) i/c PCNases; limited G (-): E.Coli, Proteus, Klebsiella
Cephalexin (Keflex): PO; Cellulitis, Cystitis
Cefazolin (Ancef, Kefzol): IV; Surgical prophylaxis (protect against skin bugs)

2nd GenerationSpectrum: G (+): Same as 1st Gen plus G (-): H.Influenzae, Neisseria
Cefuroxime (Zinacef): PO, IV; Limited anaerobes; Cross BBB
Cefoxitin (Mefoxin): IV; Abdominal surgery prophylaxis; Excellent against Anaerobes (i.e. DM foot infections, Peritonitis, etc)

3rd GenerationSpectrum: Excellent G (-) coverage; limited G (+)
Ceftriaxone (Rocephin): IV; qd dosing; Crosses BBB; Meningitis, Encephalitis, Gonorrhea
Ceftazidime (Fortaz): IV; Pseudomonas, Neutropenic Sepsis, Serious infx only; Cross BBB

4th GenerationSpectrum: Excellent G (+), Excellent G (-) coverage i/c Pseudomonas; Cross BBBSE: Psuedomembranous Colitis (C.Dif) most frequent in class
Cefipime: IV; Cross BBB; Complicated UTI, Severe Sepsis
Cefdinir: PO

5th Generation
Spectrum: Excellent G (+), Excellent G (-) coverage i/c MRSA
Ceftaroline: IV/IM; Pneumonia and Skin infections including MRSA
Ceftobiprole (proposed): Not yet available, but on FDA Fast-track; Claims more extensive coverage with less susceptibility though FDA states studies not conclusive



Beta Lactams: The Carbapenems

Carbapenems
Spectrum: Broadest Spectrum of any Antibiotic; Indicated for severe bone, skin, tissue infections, as well as Endocarditis, Abdominal infx, Pneumonia, UTIs, Sepsis, Acinetobacter
Used as last resort in hospitalized patientOnly obvious omission is lack of coverage against C.Difficile, Atypicals, and MRSA
Restricted use by ICU IV infusion for significant infections, to keep resistance low
SE: Nephrotoxicity and Seizures (usually with preexisting Renal or CNS disease) Preg Cat C
Imipenem (Primaxin): IV; Combined with Cilastatin to block enzyme that breaks down drug
SE: Sz in 1.5% of pts on typical dose, 10% if above 500 mg q6h (So not for Meningitis)
Meropenem: IV; May kill G (+) a bit slower than Imipenem, but less Sz, no need for Cilastatin

Beta Lactams: The Monobactams

Monobactams
Spectrum: Limited to aerobic G (-) i/c Pseudomonas; Severe systemic infections and UTIsThis powerful GNR drug is usually combo with Vanco or Clinda for Powerful Broad spectrum
Preg Cat B
Safe to administer to pt w/PCN allergy
Crosses BBB
SE: Severe nephrotoxicity if given with aminoglycosides; Monitor renal function even if given alone; Eosinophilia rarely
Aztreonam: IV, Advantage of preserving all normal G (+) and anaerobic flora

Macrolides
Class Facts:
Broad Spectrum: Similar coverage to PCN plus Atypicals (Chlamydia and Mycloplasma), plus Spirochetes (Syphillis and Lyme) plus additional G (-) i/c H.influenzae
As a rule, Clarithromycin has most and Azithromycin the least G (+) coverage
Bacteriostatic, inhibiting protein synthesis
Do NOT cross BBB, so not for meningitis
Except Azithromycin, CP450 inhibited, increasing drug levels of Theophylline, Digoxin, Coumadin, etcFood decreases absorption of Macrolides
Often used as alternative when pt is PCN allergic
Can cause QT prolongation and Rhabdomyolysis (especially with Statins)
Exhibits Enterohepatic recycling (excreted in bile, then reaborbed; cx for buildup to toxic levels)
Since excreted in bile, not kidneys, no need for adjustment in renal failure
Azithromycin: IV, PO; qd dosing; No effect on CP450 so fewer drug interactions, and no enterohepatic recycling; Atypical Pneumonia, Chlamydia
Clarithromycin: PO; H.Pylori, Pneumonia, M.Avium Complex
Erythromycin: PO, IV, Topical, Opthalmic; Acne, Skin Infx, Eye infx, Diabetic Gastroparesis
SE: Cholestatic jaundice, GI distress (overall a very safe drug)

Fluoroquinolones
Class Facts:
Spectrum: Broad coverage of G (-), variable G (+), broad coverage of Atypicals
As a rule, increasing Generations have better G (+) and anaerobic coverage, but less Pseudomonas
Bactericidal, inhibiting bacterial DNA production
Precautions
Cx w/arrhythmias, CI if pt on antiarrhythmic meds
As a rule, any abx that targets bacterial flora (G -), effects coagulation by inhibiting Vitamin K
Preg Cat C
Binds Ca, Al, Zn, Mg so do not administer with Milk, Vitamins, or Antacids
Electrolyte interference may cause arrhythmias (QT prolongation), Seizures, Neuropathy, and this is increased when taking with NSAIDs
May cause weakness in M.Gravis
May cause Pseudomembranous colitis, Rhabdomyolysis
Spontaneous tendon rupture can occur when taken with Corticosteroids
Do not administer with Milk, Vitamins, or AntacidsHigh % of unmetabolized drug is excreted in urine, making it excellent for UTI
1st Gen: Did not contain Fl, and were just Quinolones; Much less effective, not used today
2nd Gen: Best antipseudomonal and G (-) in class; weakest G (+) and anaerobe
Ciprofloxacin: PO, IV, Opthalmic; Nosocomial Pneumonia, UTI, Infx Diarrhea (not C.Dif); Not for children below 18
3rd Gen: Levofloxacin (Levaquin): IV, PO; qd dosing; UTI, Community (CAP) or Legionella Pneumonia
4th Gen: Best G (+) and anaerobe in class; weakest G (-) and antipseudomonal in class Moxifloxacin: Pneumonia (CAP); Only Quinolone not renally excreted

Aminoglycosides
•Class Facts:
–Spectrum: Primarily aerobic G (-) coverage i/c Pseudomonas, some G (+) staph
–Often used in combination with G (+) drugs for Broad Spectrum coverage; Rarely used alone
–Quinolones are often used initially instead, due to high resistance to this class, unless high suspicion of Pseudomonas
–Bactericidal, blocking protein synthesis
–Allergies are very uncommon with this class
Precautions:Nephrotoxicity (renal failure) and Ototoxicity (hearing loss) fairly common, so not for long term –Nephrotoxicity risk increased when taking with Vanco, Cyclosporine, or IV contrast–Ototoxicity risk increased when taking with Loop Diuretics
Measure Trough concentrations to assure efficacy, at least every 5d (30m before next dose)
Most Preg Cat D (exception is Streptomycin which is a B)
•Decrease intestinal Vitamin K synthesis (anticoagulant quality)
•Can bind Ca, causing neuromuscular weakness and neuropathy
Not absorbed well, so no PO
•Streptomycin: Eye infx, Tuberculosis; Limited use due to high resistance
•Tobramycin: Best antipseudomonal in class; MRSA (w/Ampicillin)
•Gentamicin: Excellent antipseudomonal; Endocarditis (w/PCN)
•Neomycin: Hepatic Encephalopathy (kills Ammonia producing GI flora); Only drug in class given PO as it is used to clean GI tract and is not absorbed; Very toxic if given IV
•Amikacin: Synthetic derivative of Neomycin; Often still effective when bugs are resistant to all other Aminoglycosides

Tetracyclines
•Class Facts:
–Spectrum: Very broad coverage of G (-), G (+), Atypicals, Protozoa; i/c Chlamydia, Mycoplasma, and Acinetobacter–Broad spectrum limited only by significant resistance, and indications now i/c: Acne, Rosacea, Anthrax, Bubonic Plague, Elephantitis, Malaria, Cholera, Syphillis, Rickettsia (Q fever)–Also inhibits ADH, and is used for SIADH–Bacteriostatic, inhibiting protein synthesis
Precautions
•With odd strength comes odd SE; These i/c: Candida superinfections, Pseudomembranous Colitis (C.Dif), Thrombocytopenia, Coagulation irregularities, Hemolytic anemia, Lupus exacerbations, Nephrotoxicity•Bind Ca, Mg, Al, so do not give with milk, antacids, or iron salts; Also cause tooth discoloration in growing teeth (young pts); Cause weakness in M.Gravis
•Preg Cat D–Cause fibrosis in pleura, so used for direct administration to resolve pleural effusions
Doxycycline (Vibramycin): PO, IV; You name it this will treat it, but use less harmful drugs, if effective, first
•Demeclocycline (Declomycin): PO; Reserved for the treatment of SIADH

Miscellaneous

Bactrim
•PO, IV; Sulfonamide, primarily used for UTI and Pneumocystis Carinii Pneumonia (in HIV pt)
•SE: Renal stones, Stevens Johnson syndrome, Allergic reaction common; Many drug interactions; Blood Dyscrasias (report any s/s of new infx)

Vancomycin•PO, IV; Spectrum i/c all G (+); Used for MRSA and MRSE; PO is useful for C.Dificile Colitis
•SE: Nephro/Ototoxic (Measure Peak/Trough levels); Red Man Syndrome (from rapid infusion; 60m min)

Metronidazole
•PO, IV; Excellent GPR/GNR Anaerobic coverage, used for intrabdominal; C.Dificile Colitis
•SE: Serious reaction if taken within days of Alcohol

Clindamycin
•PO, IV; Excellent Anaerobic coverage (rule is Clinda above diaphragm, Metro for below) as well as G (+)
•Often used for serious G (+) sepsis w/possible anaerobic component (i.e. postop abdomen surgery)
•Does not cross BBB; Esophagitis common if not administered with water
•SE: Pseudomembranous Colitis (C.Dif) common post treatment (10%)

Linezolid (Zyvox)
•PO, IV; Spectrum similar to Vanco plus most anaerobes; Used for VRSA, VRE
•SE: May decrease platelet count (3%); MAOI w/high risk of Serotonin Syndrome with SSRIs

Synercid
•IV; Alternative to Zyvox for VRSA, VRE
•SE: Serious arthralgia, myalgias; Central line only as thrombophlebitis in up to 75% of pts via Peripheral

Colistin
•IV; Mainly used for treatment of Acinetobacter and severe Pseudomonal infx; Spectrum i/c GNR
•Was actually first G (-) drug on market, gradually replaced by Aminoglycosides, then brought back into use by developing resistance to those drugs
•Developed so long ago, no actual recommended dosages have been studied (nightmare to prescribe)
•SE: Nephrotoxicity, Neurotoxicity (less common than with Aminoglycosides)

Antibiotics made EZ

Whether you are studying for your NCLEX or USMLE examination, or you are a practicing nurse or physician, the first step in understanding antibiotic drugs, is to know about the bugs you are trying to kill. We will take a two blog look at this subject, first by summarizing the bacteria that we frequently encounter in the hospital.

First lets take a broad look at bacteria:

Gram Positive CocciSTAPHYLOCOCCUS sp.
•STAPH. AUREUS
•STAPH. EPIDERMITIS
STREPTOCOCCUS sp.
•STREP. PNEUMONIAE
•STREP. VIRIDANS
•STREP. PYOGENES (GAS)
•STREP. AGALACTIAE (GBS)
ENTEROCOCCUS sp.

•Gram Positive Rods
LISTERIA
CORNYBACTERIUM DIPTHERIAEBACILLUS ANTHRACIS (anaerobe)
CLOSTRIDIUM (anaerobes)
•c. DIFFICILE
•c. TETANI
•c. BOTULINUM
•c. PERFRINGES

Gram Negative Cocci
–NEISSERIA MENINGITIS
–NEISSERIA GONORRHEA
–MORAXELLA CATARRHALIS

Gram Negative RodsENTERIC BUGS•ESCHERICHIA COLI
•PROTEUS sp.
•ENTEROBACTER sp.
•HELICOBACTER sp.
•SALMONELLA sp.
•SHIGELLA sp.
•KLEBSIELLA sp.
–HAEMOPHILUS INFLUENZAE
–LEGIONELLA sp.
–PSEUDOMONAS AERUGINOSA
–ACINETOBACTER sp.
–BACTEROIDES (anaerobes)
•B. FRAGILIS

Atypical Bacteria: Think Doxy!
–CHLAMYDIA (intracellular)
–MYCOPLASMA (no cell wall)
–SPIROCHETES (curves: Syphillis)
–BORRELA (Corkscrews: Lyme)
Think INH/Rifampin/Azithro
–MYCOBACTER (Acid fast: TB, Leprosy, M.Avium Complex)




Gram Positive Cocci

Staphylococcus
Staph aureus (coagulase positive)
•Most pathogenic of the staphs; toxins cause Toxic Shock, Scalded Skin, Gastroenteritis
•Cause skin infections, Pneumonia (nosocomial), Endocarditis, OsteomyelitisAbscess formation common; Can initiate clotting (think DIC)
•Tx: Oxacillin family; (Vancomycin if MRSA; Zyvox if VRSA; Bactrim or Doxy if Community MRSA)
–Also susceptible to: 1/2/4 Gen Cephs, Carbapenems, Macrolides
MRSA: Staph resistant to Oxacillins and most other drugs; Use Vanco, Zyvox, or Synercid

Staph epidermidis (coagulase negative)
•Normal flora of human skin
•Causes infection in immuno-compromised or depressed patients often via Central lines
•Tx: Similar to Staph Aureus (Vanco if MRSE, Zyvox if VRSE)

Streptococcus
Alpha HemolyticStrep pneumoniae (Pneumococcus): Leading cause of Pneumonia, Otitis Media, and Meningitis
Strep viridans: Normal flora of mouth, can cause Dental abscess and Endocarditis

Beta Hemolytic
•Group A (Strep pyogenes): Strep throat, Rheumatic fever, Scarlet fever, Glomulerulonephritis, Necrotizing fasciitis•Group B (Strep agalactiae): Can colonize vagina and cause Meningitis or Pneumonia in newborn
–Tx: PCN G; (Quinolone if PCN resistant; Ceftriaxone if in brain)
•Also susceptible to: 1/2/4 Cephs, Macrolides, AminoPCNs, Vancomycin, Quinolones

Enterococcus
–Facts
•Common nosocomial infection with multi-drug resistance
•Cause Sepsis, Cellulitis, Intraabdominal infx, Endocarditis, UTI
•Tx: Ampicillin (or Vancomycin) + Gentamycin; (Zyvox or Synercid if VRE)
–Only other effective drugs: Zosyn, Imipenem, and Quinolones




Gram Positive Rods

•Listeria
–Commonly reside in soil, sewage, and stream water but rarely cause disease; If the immune response is slow, however, they move into cells and then are missed by immune cells
–Cause of Listeriosis, a lethal food bourne illness with mortality rate of 25%; Can invade CNS
–Tx: Ampicillin (often with Gentamicin)

•Cornybacterium diptheriae
–Toxin producing (2nd most lethal toxin to humans) causes Pharyngitis w/heart/CNS damage
–Tx: Antitoxin + PCN (Erythromycin if PCN allergic)

•Bacillus anthracis
–This anaerobic bacteria is the cause of Anthrax (meaning Coal = large black lesions)
–Lives in soil, and can be ingested by grazing animals where it causes rapid death (is then possible to inhale or ingest the bacteria from dead animals)
–Tx: PCN; (Cipro or Doxycycline if PCN allergic)

•Clostridium (anaerobic species)
C. difficile
•Overgrowth in gut after Antibiotic treatment (Clindamycin, 3/4 Gen Cephs, Amp/Amox), causes Pseudomembranous Colitis•Tx: PO Metronidazole (or PO Vancomycin if relapse after taking Metro)
–C. tetani
•Toxin producing (3rd most lethal toxin to humans) causes PNS blockade (Tetany, Seizure, Death)
•Tx: Toxin irreversible once bound, so rapid treatment with PCN or Metronidazole imperative
–C. botulinum
•Toxin producing (Most lethal toxin to humans; 500 g could kill the entire world) that causes Botulism (a nerve blockade disease that leads to rapid paralysis and death)
•Bacteria can not survive in high oxygen or acidic environment, so usually ingesting bacteria not fatal as they are killed rapidly in GI tract; Must ingest toxins to have effects
•Infants (pre solid food) have a less acidic GI tract, so things harboring this bacteria (honey) can deliver the organism, which is then allowed to grow in more basic pH GI tract
•Tx: Hardy bacteria are not killed by antibiotics; Antitoxin very hard to find so Mechanical Ventilation and removal of cause (i.e. vomiting or debridement of wound) usually only thing possible




Gram Negative Cocci

Neisseria meningitidis (aka Meningococcus)
–Common cause of meningitis; Also Meningococcemia (a rapidly fatal sepsis that kills over 50% of effected infants) and DIC
–Tx: PCN G (Ceftriaxone if PCN allergic) ; Best treatment is prevention with vaccine

Neisseria gonorrhea–Cause of the STD Gonorrhea, as well as Conjunctivitis in newborn of infected mom
–Tx: Ceftriaxone (or Ciprofloxacin) and Azithromycin for possible concurrent Chlamydia

•Moraxella catarrhalis
–Causes URI and Otitis Media, as well as Pneumonia in smokers; Also COPD exacerbations
–Tx: Augmentin and Erythromycin
•Also susceptible to 2/3 Gen Cephs, Quinolones, Bactrim




Gram Negative Rods

A very common bug to recognize during your NCLEX or USMLE studying. It is useful to divide this class into the usual medical pathologies caused by each

•Urinary pathogens

–E. coli
•Normal intestinal flora cause 90% of UTI; Also Pyelonephritis
•Pathogenic varieties are not normal flora and can cause Infectious diarrhea, Hemolytic Anemia
•Tx: Ciprofloxacin or Bactrim (Zosyn also effective)

–Proteus
•Causes UTI, in addition to renal calculi (struvite, CaCO3)
•Tx: Levaquin or Bactrim (Often treated without knowing you are treating Proteus)

Respiratory pathogens

Haemophilus influenzae

•Cause: Pneumonia, AOM; Also Sepsis, Meningitis, Cellulitis
•Tx: Azithromycin
–Also susceptible to po 3/4 Gen Cephs, Augmentin, Doxycycline, Quinolones, Carbapenems
Klebsiella pneumoniae
•Usually only pathogenic in hospitalized immunocompromised causing Pneumonia and/or Sepsis
•Rapid resitance develops, especially against Cephalosporins and Quinolones
•S/S: Profuse, Jelly-like, Bloody sputum and high mortality rate
•Tx: Carbapenems or Zosyn

–LegionellaPneumonia, derived airborn from water ducts, air conditioning units, water towers
•Tx: Macrolide (or Quinolone or Doxycycline)

Pseudomonas aeruginosa
•Opportunistic infection causes Pneumonia, Sepsis, UTI, Right side Endocarditis, Osteomyelitis in Diabetic foot ulcers•First s/s often overwhelming Gram negative sepsis; 2nd most common cause of infection in ICU
•Extremely resistant to many drugs; All effective drugs IV, except Cipro and Levaquin so their use is severely restricted to avoid development of resistant strains
•Tx: Ceftazidime and Gentamycin (or Imipenem or Zosyn- varies widely between hospitals)
–Also susceptible to the following: Tobramycin, Cefipime, Colistin, Aztreonam

Acinetobacter
Pneumonia, Sepsis, Shock common, Up to 70% mortality; Can live 3 weeks on dry surface
•Tx: Imipenem
–Colistin or Doxycycline is alternative

Gastrointestinal pathogens

Helicobacter Pylori

•Common cause of Peptic Ulcer Disease
•Tx: (CAP) Clarithromycin, Amoxicillin, PPI (proton pump inhibitor)

Salmonella
•Common cause of Diarrhea; Some forms also cause Typhoid or Sepsis
Ciprofloxacin (rule out C.Dif with any infectious diarrhea)

Shigella
•Causes bloody, purulent diarrhea in nursing homes and preschools
•Tx: Ciprofloxacin

Vibrio Cholera
•Causes rice water diarrhea, with death from dehydration
•Tx: Doxycycline, fluids and electrolytes

–Yersenia•One form causes diarrhea; Another form causes Bubonic Plague
•Tx: Gentamicin

•GNR and Sepsis: Notes of Interest
–Many GNR have endotoxins, which are actually components of their cell wall
•When antibiotics begin their destruction, these toxins are released into the bloodstream in massive quantities, leading to Sepsis (Massive immune response) and eventually Septic Shock (Low BP and organ dysfunction)
•For this reason, Bacteremia (bugs in blood) with GNR is among the most serious of diseases, and should be treated aggresively in an ICU
•With Shock and 2 organs dysfunctioning the mortality rate is over 40%; With each additional organ dysfunction add 15%
Sepsis is the #1 killer in the ICU, but is more preventable than you would think; The dirty source, is more often than not, indwelling catheters, so take extreme care with hygiene if you are ICU bound!!!