Verapamil grapefruit juice effect

Buspirone (BuSpar) [Anxiolytic] WARNING Closely monitor for worsening depression or emergence of suicidality Uses Short-term relief of anxiety Action Antianxiety antagonizes CNS serotonin receptors Dose Initial 7.5 mg PO bid T by 5 mg q2-3d to effect usual 20-30 mg/d max 60 mg/d Contra w/ MAOI Caution [B, /-] Avoid w/ severe hepatic/renal insuff Disp Tabs SE Drowsiness, dizziness, HA, N, EPS, serotonin synd, hostility, depression Notes No abuse potential or physical/psychologic d endence Interactions T Effects W/ erythromycin, clarithromycin, itraconazole, ketoconazole, diltiazem, verapamil, grapefruit juice effects W/ carbamazepine, rifampin, phenytoin, dexamethasone, phenobarbital, fluoxetine EMS T Sedation w/ concurrent EtOH use grapefruit juice may T risk of adverse effects OD May cause dizziness, miosis, N/V symptomatic and supportive... 

Quazepam (Doral) [C IV] [Sedative/Hypnotic/ Benzodiazepine] Uses Insomnia Action Benzodiazepine Dose 7.5-15 mg PO hs PRN i in elderly hqjatic failure Caution [X, /-] NA glaucoma Contra PRG, sleep apnea Disp Tabs SE Sedation, hangovCT, somnolence, resp depression Interactions T Effects W/ azole antifungals, cimetidine, digoxin, disulfiram, INH, levodopa, macrolides, neuroleptics, phenytoin, quinolones, SSRIs, verapamil, grapefruit juice, EtOH effects W/carbamazepine, rifampin, rifabutin, tobacco EMS Use caution w/ other benzodiazepines, antihistamines, opioids and verapamil, can T CNS depression concurrent EtOH and grapefruit juice use T CNS depression OD May cause profound CNS depression, confusion, bradycardia, hypotension, and altered reflexes flumazenil can be used as antidote activated charcoal may be effective... 

Simvastatin (Zocor) [Anrilipemic/HMG-CoA Reductase Inhibitor] Uses X Cholesterol Action HMG-CoA reductase inhibitor Dose Adults. 5-80 mg PO w/ meals X in renal insuff Peds. 10-17 y 10 mg, 40 mg/daily max Caution [X, —] Avoid concurrent use of gemfibrozil Contra PRG, liver Dz Disp Tabs 5,10, 20, 40, 80 mg SE HA, GI upset, myalgia, myopathy (muscle pain, tenderness or weakness w/ creatine kinase 10 x ULN), Hep Interactions T Effects OF digoxin, warfarin T risk of myopathy/iiiabdomyolysis W/ amiodarone, cyclosporine, CYP3A4 inhibitors, fibrates, HIV protease inhibitors, macrolides, niacin, verapamil, grapefruit juice X effects W/ cholestyramine, colestipol, fluvas-tatin, isradipine, propranolol EMS T Effects of warfarin use amiodarone and... 

Lovastatin (Mevacor/ Altocor) [Antilipemic/HMG-CoA Reductase Inhibitor] Uses Hypercholesterolemia Action HMG-CoA reductase inhibitor Dose 20 mg/d PO w/ PM meal may T at 4-wk intervals to 80 mg/d max or 60 mg ER tab take w/ meals Caution [X, -] Avoid w/ grapefruit juice, gemfibrozil. Contra Active liver Dz Disp Tabs SE HA GI intolerance common promptly report any unexplained muscle pain, tenderness, or weakness (myopathy) Interactions T Effects W/ grapefruit juice T risk of severe myopathy W/ azole antifungals, cyclosporine, erythromycin, gemfibrozil, HMG-CoA inhibitors, niacin T effects OF warfarin >1 effects W/ isradipine, pectin EMS t Risk of photosensitivity Rxns T effects of warfarin concurrent EtOH use t risk of liver tox diltiazem and verapamil can T risk of lovastatin tox OD Unlikely to cause life-threatening Sxs... 

Verapamil, diltiazem, erythromycin, and itraconazole all increase the plasma concentration of buspirone. The plasma concentration is decreased almost 10-fold by rifampicin. Grapefruit juice increases the overall subjective effect of the drug (Mahmood and Saha-jwalla, 1999). 

Fuhr U, Muller-Peltzer H, Kern R, et al. Effects of grapefruit juice and smoking on verapamil concentrations in steady state. Eur J Clin Pharmacol 2002 58(l) 45-53. 

Ho PC, Ghose K, Saville D, Wanwimolruk S. Effect of grapefruit juice on pharmacokinetics and pharmacodynamics of verapamil enantiomers in healthy volunteers. Eur J Clin Pharmacol 2000 56(9-10) 693-698. 

Zaidenstein R, Dishi V, Gips M, et al. The effect of grapefruit juice on the pharmacokinetics of orally administered verapamil. Eur J Clin Pharmacol 1998 54(4) 337-340. 

CALCIUM CHANNEL BLOCKERS GRAPEFRUIT JUICE t bioavailability of felodipine and nisoldipine (with reports of adverse effects), and t bioavailability of isradipine, lacidipine, lercanidipine, nicardipine, nifedipine, nimodipine and verapamil (without reported adverse clinical effects) Postulated that flavonoids in grapefruit juice (and possibly Seville oranges and limes) inhibit intestinal (but not hepatic) CYP3A4. They also inhibit intestinal P-gp, which may t the bioavailability of verapamil Avoid concurrent use of felodipine and nisoldipine and grapefruit juice... 

---