Top 100 Drug Interactions Flashcards
N-acetylcysteine
No clinically significant drug interactions
Acetaminophen
CYP inducers (PS PORCS)- such as phenytoin and carbamazepine- increase rate of NAPQI production/liver toxicity, after acetaminophen overdose
acyclovir
Probenecid and interferon increase acyclovir concentrations.
adenosine
Dipyridamole blocks cellular reuptake of adenosine. Theophylline is a competitive agonist at adenosine receptors.
epinephrine
Beta-blockers can induce widespread vasoconstriction.
Aldosterone antagonists
ACE inhibitors; ARBs and other K-elevating drugs/supplements increase hyperkalemia risk.
Antacids/alginates
- Divalent ions reduce serum concentration of drugs such as bisphosphonates, levothyroxine, tetracyclines, digoxin, and PPIs. Take antacid either 4 hours before or 2 hours after taking this medication.
- Antacids increase the alkalinity of urine and so increase lithium and aspirin excretion.
Albendazole
- Plasma concentrations are lowered by phenytoin and carbamazepine.
- Cimetidine increases albendazole concentration.
Allopurinol
- Toxicity risk of mercaptopurine/azathioprine increases because allopurinol inhibits xanthine oxidase.
- Amoxicillin increases skin rash risk.
- ACE inhibitors and thiazide diuretics increase the risk of hypersensitivity reactions.
Alpha blockers
- Other blood pressure-lowering drugs increase the risk of first-dose hypotension and hypotension risk generally thereafter.
Aminoglycosides
- Loop diuretics/vancomycin increase ototoxicity risk.
- Cyclosporine, platinum chemotherapy, cephalosporins, and vancomycin increase kidney toxicity risk.
Aminosalicylates (sulfasalazine, mesalazine, olsalazine, balsalazide)
- PPIs increase gastric pH and so may affect gastric coating of aminosalicylates.
- Lactulose reduces stool pH and so can prevent 5-ASA release into the intestine.
Amiodarone
Amiodarone increases the plasma concentration of digoxin, diltiazem and verapamil (increasing risk of AV block, bradycardia and heart failure)
ACE inhibitors/ARBS
- Hyperkalemia risk increases when taken with other K-elevating drugs/supplements.
- Renal failure risk increases when taken with NSAIDs.
Amphotericin B
- Increased risk of flucytosine toxicity
- Increased renal toxicity with cisplatin/diuretics
- Increased risk of hypokalemia with corticosteroids
- Renal damage with aminoglycosides/other nephrotoxic drugs
Antidepressants
- Serotonin syndrome with taken with other serotonergic drugs, such as MAO inhibitors.
- TCAs augment antimuscarinic and sedative effects of other drugs.
Antiemetics: H1 antagonists (diphenhydramine, meclizine, promethazine, doxylamine succinate)
- Sedation risk increases when taken with other sedative drugs (benzos, etc.)
- Anticholinergic effects are more pronounced when taken with ipratropium/tiotropium
Antiemetics (prochlorperazine, chlorpromazine)
- QT prolongation risk increases when taken with antipsychotics, quinine, SSRIs, macrolides, fluoroquinolones, and ciprofloxacin
Antifungal Drugs: fluconazole
- Fluconazole inhibits CYP enzymes- increasing plasma concentration of phenytoin, carbamazepine, warfarin, simvastatin, and sulfonylureas.
- Reduces the antiplatelet effect of clopidogrel.
- Risk of arrhythmias increases with taken with QT-prolonging drugs.
Antihistamines (H1 antagonists)
1st gen: diphenhydramine (Benadryl) and hydroxyzine (Vistaril/Atarax)
2nd gen: fexofenadine (Allegra), loratadine (Claritin), cetirizine (Zyrtec)
- No major drug interactions.
Loperamide
P-glycoprotein inhibitors (quinidine, ritonavir, ketoconazole) increase loperamide levels.
Antimuscarinics (cardiovascular: atropine, hyoscine butylbromide)
(genito-urinary: oxybutynin, tolterodine, solifenacin)
- Antimuscarinic effects more pronounced when taken with other drugs with the same effects, such as tricyclic antidepressants.
Antipsychotics: typical and atypical drugs
Avoid with QT-prolonging drugs. Avoid with dopamine-blocking antiemetics.
Aspirin
Antiplatelet and anticoagulant drugs increase bleeding risk.