|
| Drugs | Frequency | Severity | Risk of interaction |
|
| Atorvastatin + cimetidine | 22 | Major | Increase the level of anticoagulation |
| Omeprazole + clopidogrel | 18 | Major | Decrease effect of clopidogrel |
| Ceftriaxone + heparin | 15 | Major | Increase effect of atorvastatin |
| Warfarin + metronidazole | 11 | Major | Increase bleeding risk |
| Cimetidine + clopidogrel | 11 | Major | Decrease effect of clopidogrel |
| Warfarin + cimetidine | 8 | Major | Increase effect of warfarin |
| Digoxin + nifedipine | 7 | Significant | Increase the level of digoxin |
| Azithromycin + heparin | 6 | Major | Increase effect of heparin |
| Omeprazole +digoxin | 6 | Major | Increase risk of digoxin level |
| Digoxin + azithromycin | 6 | Major | Increase level of digoxin |
| Morphine + clopidogrel | 6 | Major | Decrease effect of clopidogrel |
| Azithromycin + warfarin | 5 | Major | Increase effect of warfarin |
| Warfarin + ciprofloxacin | 5 | Major | Increase the effect of ciprofloxacin |
| Aspirin + enalapril | 5 | Major | Decrease renal function |
| Enalapril + NPH | 5 | Significant | Increase effect of insulin |
| Warfarin + heparin | 3 | Major | Both increase anticoagulation |
| Dexamethasone + cimetidine | 3 | Major | Increase level of dexamethasone |
| Digoxin + metoprolol | 3 | Major | Increase risk of braycardia |
| Cimetidine + hydrocortisone | 2 | Major | Increase effect of hydrocortisone |
| Dexamethasone + rifampicin | 2 | Major | Decrease effect of dexamethasone |
| Morphine + tramadol | 1 | Major | Increase dependency |
| Omeprazole + isoniazid | 1 | Major | Increase effect of omeprazole |
| Spironolactone + potassium chloride | 1 | Major | Risk of hyperkalemia |
| Omeprazole + rifampicin | 1 | Major | Decrease effect of omeprazole |
| Haloperidol + ondansetron | 1 | Major | Both increase QT interval |
|
