| Drug class | Drugs potentially affected by grapefruit | Effects of interaction |
| Antiarrhythmics | Amiodarone (cordarone)disopyramide (norpace), quinidine | Increased plasma concentrations of amiodarone may cause thyroid or pulmonary toxicity, liver injury, prolongation, proarrhythmic disordersand bradycardia. Increased plasma concentration of quinidine and disopyramide may be cardiotoxic causing torsades depointes. |
| Calcium channel blockers | Felodipine (plendil), nicardipine (cardene)nifedipine (procardia), nimodipine (nimotop), nisoldipine (sular) | Increased plasma concentration may lead to flushingperipheral edema, headaches, tachycardia, symptomatic hypotensionand myocardial infarction in rare cases. |
| Statins | Atorvastatin (lipitor), lovastatin (mevacor)simvastatin (zocor) | Increased plasma concentration may cause headaches, gastrointestinal complaints, hepatic inflammation, and myopathies (e.g., rhabdomyolysis). |
| Immunosuppressants | Cyclosporine (sandimmune, neoral)tacrolimus (prograf) | Increased drug exposure without effects on peak concentration may cause increased adverse events or toxicity evidenced by renal toxicityhepatic toxicity, and increased immunosuppression. |
| Protease inhibitors | Saquinavir (fortovase) | Increased plasma concentrations may cause increased side effects such as headache, fatigue, insomnia, and anxiety. |