Table 2 List of major drug–drug interactions with their potential risks
Interacting drugs | Number of patients | Documentationa | Potential risks |
|---|---|---|---|
Anti TB(HRZ) + phenytoin | 2 | Good | Decreased phenytoin and/or rifampin exposure |
Aspirin + cimetidine | 1 | ND | |
Aspirin + clopidogrel | 5 | Fair | Increased risk of bleeding |
Aspirin + enoxaparin | 2 | Good | Increased risk of bleeding |
Aspirin + fluoxetine | 1 | Good | Increased risk of bleeding |
Aspirin + omeprazole | 1 | ND | |
Ciprofloxacin + amitriptyline | 1 | Fair | Increased risk of QT interval prolongation |
Ciprofloxacin + doxorubicin | 1 | Fair | Increased doxorubicin exposure |
Clarithromycin + amitriptyline | 1 | Fair | Increased risk of QT-interval prolongation |
Clarithromycin + amlodipine | 1 | Excellent | Increased amlodipine exposure |
Clarithromycin + digoxin | 2 | Excellent | Digoxin toxicity (nausea, vomiting, arrhythmias) |
Clarithromycin + nifedipine | 1 | Moderate fair | Increased nifedipine plasma concentrations |
Clarithromycin + tramadol | 3 | Fair | Increased risk for seizures, serotonin syndrome, and opioid-related toxicity |
Clarithromycin + atorvastatin | 1 | Good | Increased risk of myopathy or rhabdomyolysis |
Clopidogrel + cimetidine | 3 | Fair | Reduction in clinical efficacy of clopidogrel |
Clopidogrel + diclofenac | 1 | Excellent | An increased risk of bleeding |
Clopidogrel + omeprazole | 1 | Excellent | Reduction in clinical efficacy of clopidogrel and increased risk for thrombosis |
Cyclophosphamide + allopurinol | 3 | Good | Cyclophosphamide toxicity (bone marrow suppression, nausea, vomiting) |
Cyclophosphamide + doxorubicin | 3 | Fair | Increased risk of cardiomyopathy |
Heparin + aspirin | 14 | Fair | Increased risk of bleeding |
Heparin + enoxaparin | 1 | Fair | Increased risk of bleeding |
Heparin + clopidogrel | 4 | Fair | Increased risk of bleeding |
Heparin + diclofenac | 1 | Fair | Increased risk of gastrointestinal bleeding |
Heparin + indomethacin | 3 | Excellent | Increased risk of gastrointestinal bleeding; reduced effectiveness of indomethacin for the treatment of patent ductus arteriosus |
Hydralazine + metformin | 1 | ND | |
Hydralazine + norfloxacin | 1 | ND | |
Insulin + norfloxacin | 2 | Fair | Changes in blood glucose and increased risk of hypoglycemia or hyperglycemia |
Insulin + ciprofloxacin | 2 | Fair | Changes in blood glucose and increased risk of hypoglycemia or hyperglycemia |
Potassium chloride + enalapril | 2 | Good | Hyperkalemia |
Simvastatin + azithromycin | 2 | Good | An increased risk of rhabdomyolysis |
Simvastatin + ciprofloxacin | 2 | Good | Increased risk of myopathy or rhabdomyolysis |
Spironolactone + digoxin | 2 | Good | Increased digoxin exposure |
Spironolactone + enalapril | 10 | Good | Hyperkalemia |
Spironolactone + potassium chloride | 4 | Fair | Hyperkalemia |
Tramadol + chlorpromazine | 2 | Fair | Increased risk of seizures |
Tramadol + amitriptyline | 1 | Fair | Increased risk of seizures, serotonin syndrome (hypertension, hyperthermia, myoclonus, mental status changes), opioid toxicity, and increased concentrations of tramadol and decreased concentrations of tramadol active metabolite |
Warfarin + aspirin | 3 | Fair | Increased risk of bleeding |
Warfarin + azithromycin | 2 | Good | Increased risk of bleeding |
Warfarin + ciprofloxacin | 3 | Good | Increased risk of bleeding |
Warfarin + clarithromycin | 3 | Good | Increased risk of bleeding |
Warfarin + metronidazole | 6 | Good | Increased risk of bleeding |
Total | 105 |