Pharmacology 1 Flashcards
Drugs known for drug-drug interactions (4)
- Macrolides (erythromycin, clarithromycin)
- Antifungals (ketoconazole, fluconazole)
- Cimetidine (Tagamet)
- Citalopram (Celexa)
Drugs affected by grapefuit juice (8)
- Statins
- Erythromycin
- CCB (nifedipine, nisolidipine)
- Antivirals
- Amiodarone
- Benzodiazepines (diazepam, triazolam)
- Carbamazepine
- Buspirone
Proton-pump inhibitors (PPIs) safety issues
Increased risk of fx (postmenopausal women), PNA, C diff, hypo-Mg, B12 & iron malabsorption, atorphic gastritis, kidney Dz
Omeprazole (Prilosec) safety issues
PPI: interacts w/ warfarin (Coumadin), diazepam (Valium), carbamazepine (Tegretol), phenytoin (Dilantin), ketoconazole (Nizoral)
Warfarin (Coumadin) safety issues
Interacts w/ “G” herbs (garlic, ginger, ginko, ginseng; other herbs/supplements (feverfew, green tea, fish oil); numerous drug interactions.
Discontinue 7 days prior to surgery
TZDs (thiazolidinediones) safety issues
Cause or exacerbate congestive HF in some Pts; do NOT use if NY Health Association Class III or IV HF
Pioglitazone (Actos) safety issues
TZD: Stop if causes dyspnea, wt gain, cough (HF)
Atypical antipsychotics safety issues:
Risperidone (Risperdal)
Olanzapine (Zyprexa)
High risk of wt gain (monitor wt q 3 mo.), metabolic syndrome, T2DM,
High mortality in elderly Pts
Atypical antipsychotics safety issues:
Quetiapine (Seroquel)
Monitor TSH, lipids, wt/body mass index
Bisphosphonates (osteoclast inhibitor) general safety issues
Erosive esophagitis, abdomin pain
Stop immediately when S/Sx of esophagitis or jaw pain
Take alone upon awakening w/ 8 oz water before breakfast; do not lie down for 30 min afterward; do not mix w/ other drugs; take first thing in the morning before breakfast
Bisphosphonates safety issues:
Alendronate (Fosamax)
Risedronate (Actonel)
Contraindications: Active GI Dz (GERD, PUD), CKD, esophageal stricture/varices
Statins safety issues
Do not mix w/ grapefruit juice; drug-induced hepatitis or rhabdomyolysis higher if mixed w/ azole antifungals
Simvastatin (Zocor) safety issues
High-dose (80 mg) has highest risk of rhabdomyolysis
Chinese decent: higher risk myopathy or rhabdomyolysis when taking > 40 mg/day with niacin
Increased lvl of creatine kinase
Clindamycin (Cleocin) safety issues
Higher risk of CDAD (C. diff associated diarrhea): Flagyl (PO TID x 10-14 days) + probiotics daily (BID x few wks)
Digoxin: Indication
Certain supraventricular tachyarrhythmias & HF 2/2 LV systolic dysfunction
* Not a first-line drug for controlling HR
Digoxin: Therapeutic range
0.5-2.0 ng/mL (i.e. narrow)
Digoxin: S/Sx of overdose
- GI related (anorexia, N/V, abdomin pain)
- Arrhythmias, confusion, visual changes (yellowish green tinged-color vision, scotomas)
Digoxin toxicity: Lab tests
- Digoxin level
- Electrolytes (K, Mg, Ca)
- Hyperkalemia is common in acute toxicity (Critical K vale < 2.5 or > 6.5 mEq/L)
- Creatinine
- Serial EKGs
Warfarin (Coumadin): Pregnancy Cat. & class
Pregnancy Cat. X
Vitamin K agonist
Warfarin (Coumadin): Indication
Prophylaxis & Tx thromboembolic events associated w/ A-fib or heart valve replacement (ie PE, DVT, stroke, thromboemboli)
Warfarin (Coumadin): Duration of action
2-5 days (single dose)
Warfarin (Coumadin): Target value for A-fib
INR 2-3 (ideal INR 2.5)
Warfarin (Coumadin): Initial dose
2-5 mg PO daily
Warfarin (Coumadin): Contraindications
Pregnancy, large esophageal varices, thrombocytopenia, recent eye/brain/trauma surgery, within 72 hrs of major surgery, blood dyscrasias, careful if Hx of GI bleeding
Drug classes that increase bleeding risk
Coumarins: Warfarin (Coumadin)
Direct thrombin inhibitors: Dabigatran (Pradaxa), Rivaroxaban (Xarelto)
Heparin: Heparin, LMW heparin (Lovenox)
Antiplatelet: Clopidogrel (Plavix)
Salicylate: Aspirin, magnesium salicylate, bismuth subsalicylate (Pepto-Bismol)
NSAIDs: Ketorolac (Toradol), naproxen (Aleve), ibuprofen, indomethacin
Cox-2 inhibitor: Celecoxib (Celebrex)
Warfarin (Coumadin): reversal/antidote
Vitamin K
Dabigatran (Pradaxa): reversal/antidote
Idarucizumab (Praxbind)
LMW heparin (Lovenox): reversal/antidote
Protamine sulfate
Clopidogrel (Plavix): reversal/antidote
No reversal agent, but FF plasma seem effective
ACE inhibitors: Contraindications
Eg. Enalapril (Vasotec), Captopril (Capoten)
Avoid mixing w/ potassium supplements
Careful w/ K-sparing diuretics
Dry, hacking cough –> switch to ARB
ARBs (angiotensin receptor blockers): Contraindications
Eg. Valsartan (Diovan), Losartan (Cozaar)
Avoid mixing w/ potassium supplements. Do not combine ARBs w/ ACEIs.
K-sparing diuretics: Contraindications
Higher risk of hyperkalemia if combined w/ ACEI, ARB, or potassium and w/ severe renal Dz
Potassium-sparing diuretics: Names (4)
Triameterene (Dyrenium)
Amiloride (Midamor)
Spironolactone (Aldactone)
Eplerenone (Inspra)
Beta-blockers: Names (4)
Propranolol (Inderal)
Atenolol (Tenormin)
Metoprolol (Lopressor)
indolol (Visken)
Beta-blockers: Contraindication
Pts w/ chronic lung Dz (asthma, COPD, emphysema, chronic bronchitis)
Do not discontinue beta-blockers abruptly 2/2 severe rebound (hypertensive crisis)
Phosphodiesterase 5 (PDE5) inhibitors: Names (3)
Sildenafil (Viagra)
Vardenafil (Levitra)
Tadalafil (Cialis)
Phosphodiesterase 5 (PDE5) inhibitors: Contraindications
- Do not use w/ nitrates (nitroglycerine, isosorbide dinitrate) and some alpha-blockers
- Within 3-6 mo. of MI or stroke
Citalopram (Celexa): Drug Cat., warning
SSRI, antidepressant; doses > 40mg/day can cause QT prolongation
Consistently stable INR within a range: Action
Check q 2-4 weeks
Single out-of-range INR: Action
If out-of-range is equal or < 0.5 below or above therapeutic INR (2-3), continue current dose and check within 1-2 wks
INR < 5 w/ no significant bleeding risk: Action
Omit one dose and/or reduce maintenance dose slightly; recheck INR
One missed warfarin dose: Action
Take the dose ASAP on the same day. Do not double dose the next day
Warfarin (Coumadin): Clinical pearls
- Anticoagulant effects persist for 2-5 days after discontinuation of warfarin
- Asian Pts may require lower starting and maintenence doses
