Asthma drugs made EZ

Pharmacology is often considered a dirty word in nursing and medical school, and unfortunately the NCLEX and the USMLE loves to test you on this. One subject we recently tackled in our NCLEX review course was the treatment of Asthma. Here is a summary of what we talked about...


Obstructive Pulmonary Disease (Asthma, COPD)•Medications: Site of Action
1.Adrenergic Agonists (Albuterol, etc)
2.Anticholinergics (Ipratroprium Bromide)
3.Xanthines (Theophylline)
4.Corticosteroids (Beclomethasone, etc)
5.Mast Cell Stabilizers (Cromolyn)
6.Leukotriene Antagonists (Montelukast-Singulair)


key to above figure: Allergen+IGE causes Mast cell to release histamine and leukotrienes which then seep out of blood stream and cause immune cells to inflame bronchioles. Various drugs work at different steps of this process. Some stop mast cells from releasing their products, some stop the products from leaving the blood stream, and some stop the products from causing the inflammation in the bronchioles. All three of these work directly on the immune system. On the other side of that, some drugs directly open the airway, not effecting the immunity at all. See below for the most critical details on these drugs and when we use them...

Obstructive Pulmonary Disease: Bronchodilators
1.Adrenergic Agonists (Albuterol, etc)
•Selective B2 agonists directly dilate airway; DOC for acute attack
•Albuterol: PO, inhaled via MDI; NOT for maintenance therapy
•Levalbuterol (Xopenex): Possibly less cardiac SE
•Salmeterol: Long acting (12hrs) for night s/s
•Terbutaline: Also relaxes uterus, tocolytic for premature labor

2.Anticholinergics (Ipratroprium Bromide) *technically not a dilator
•Atrovent is often combined with Adrenergics to tx COPD, as scarred airways need extra help dilating
•Slow onset, long acting best used for prevention, not acutely
•SE: Dry mouth, GI distress

3.Xanthines (Theophylline)
•Similar to Caffeine, causes bronchodilation, CNS stimulation of the respiratory center, Inotropy/chronotropy → renal perfusion → urine
•Used in cases where overuse of other bronchodilators has caused decreased effectiveness, especially used with COPD
•Slow onset, long acting best used for prevention, not acutely
•Stimulant C/I with arrhythmias, SZ, hyperthyroid, PUD
•Monitor therapeutic levels (10-20)
•Aminophylline is IV form of Theophylline

Obstructive Pulmonary Disease: Inflammation Modulators
1.Corticosteroids (Beclomethasone, etc)
•Steroids prevent further inflammation of constricted airways
•Available IV, PO or inhaled; Inhaled have benefit of being used at site of constriction without systemic effects (Rinse after!)
•DOC for asthma prevention•Beclomethasone excellent antiinflammatory with few SE
•Patients have died from not being tapered off of systemic steroids when switching to inhaled forms
•Can be used WITH albuterol for acute attacks and is given IV (Solu-Medrol)

2.Mast Cell Stabilizers (Cromolyn)
•Used to prevent the release of inflammatory mediators
•Most effective for exercise or allergen induced bronchospasm
•Also useful to control perennial allergic rhinitis
•Available PO, inhaled, and opthalmic

3.Leukotriene Antagonists (Montelukast-Singulair)
•Leukotriene receptor blockade prevents inflammatory migration into bronchiole tissue
•Used for maintenance, with effects taking up to a week
•SE: Dyspepsia, insomnia, diarrhea, and liver dysfunction
•Other ex. Zafirlukast (Accolate), Zileuton (Zyflo)

Asthma Treatment Protocol (med first introduced)

• Step 1, Mild Intermittent S/S: Short acting B2 agonists prn
• Step 2, Mild Persistent: Inh steroid + short B2 ag prn; Cromolyn + B2 ag prn for children; Theophylline or Montelukast alternative agents if above protocol ineffective
• Step 3, Moderate Persistent: Med dose inh steroid + Salmeterol (long acting B2) + short B2ag prn
• Step 4, Severe Persistent: High dose inh steroid + Salmeterol + Systemic steroid + short B2 ag prn

TB made EZ

Tuberculosis is one of the world's most beatable disease, yet remains one of the biggest killers. It also can be a killer on the NCLEX or USMLE, as these tests commonly have questions related to this infectious disease. Common subjects include the diagnostic tests and antibacterial drugs used in treatment. Lets take a quick look at this subject, and see if we can make TB EZ.

Tuberculosis

•Most common cause of death due to infection worldwide
•Bacteria are unique for their ability to form granulomas in oxygen rich areas of lungs (often the apices due to the higher O2 levels) to protect themselves from elimination
•May stay dormant for years, becoming active w/any insult to immunity
•Spread by droplets (droplet precaution taken) and only contagious when active
•S/S: Fever, night sweats, weight loss, malaise, and hemoptysis (bloody cough)
•DX:

1. • PPD: (+) if above or = 10cm in at risk or above or = 5cm in HIV, transplant, contacts (indicates exposure); The only patients that are + with above 15mm are those that shouldn't have been tested (no risk); Send for CXR if (+)
2. • CXR: (-) take INH 9 mos; Send for BAL if (+) CXR (indicates previous infection)
3. • BAL: (-) take INH 9 mos; (+) start 4 drug treatment protocol as resistance severe with Mycobacterium (indicates active infection)

•Treatment Protocol: (with most common side/adverse effect)

• Drug susceptibility test should be performed initially with culture

1. Isoniazid (INH): Hepatotoxicity
2. Rifampin: Red urine/tears/sputum/sweat
3. Pyrazinamide (PZD): Uricemia/Stones in P
4. Ethambutol: Blindness in Eyes (OR) Streptomycin: Ototoxic, Nephrotoxic

•Length of treatment can be long (up to 2 years) so patient compliance is a HUGE issue and number one cause of Antibiotic resistance present today.
•Stress to patient the fact that compliance to full regime has more than 90% cure rates, but must take meds everyday at same time!

PPD: Measure induration (redness) not just swollen area to detect if exposure has occurred.
Bottom picture shows Chest Xray with Granulomas (cavities) caused by previous TB infection


BAL: Bronchoalveolar lavage or bronchoscopy is the ONLY way of truly diagnosing TB. Think of Bigfoot...no matter how many pictures we have seen of someone that supposedly saw bigfoot, the only way to prove he exists is to capture him. Same way for infectious disease...the only truly positive diagnosis is to capture the bugs and grow them on a culture plate. So don't let them trick you on the test by saying a Positive ppd or chest xray means the patient has TB. Only then do we treat them with the 4 drug combo.