Nimodipine

Anti-Hypertensives : May increase risk of hypotension. Monitor blood pressure. ( 7.1 ) CYP3A4 Moderate and Weak Inhibitors: May increase risk of hypotension. Monitor blood pressure. Dose reduction of NYMALIZE may be needed. Avoid grapefruit juice. ( 7.2 ) CYP3A4 Moderate and Weak Inducers: May reduce efficacy of NYMALIZE. Dose increase may be needed. ( 7.3 )

7.1 Blood Pressure Lowering Drugs Nimodipine may increase the blood pressure lowering effect of concomitantly administered anti-hypertensives such as diuretics, beta-blockers, ACE inhibitors, angiotensin receptor blockers, other calcium channel blockers, α-adrenergic blockers, PDE5 inhibitors, and α-methyldopa. In Europe, nimodipine was observed to occasionally intensify the effect of antihypertensive drugs taken concomitantly by hypertensive patients; this phenomenon was not observed in North American clinical trials. Blood pressure should be carefully monitored, and dose adjustment of the blood pressure lowering drug(s) may be necessary.

7.2 CYP3A4 Inhibitors Nimodipine plasma concentration can be significantly increased when concomitantly administered with strong CYP3A4 inhibitors. As a consequence, the blood pressure lowering effect may be increased. Therefore, the concomitant administration of NYMALIZE and strong CYP3A4 inhibitors should generally be avoided [ see Warnings and Precautions (5.3) ].

Strong CYP3A4 inhibitors include some members of the following classes: macrolide antibiotics (e.g., clarithromycin, telithromycin), HIV protease inhibitors (e.g., indinavir, nelfinavir, ritonavir, saquinavir), HCV protease inhibitors (e.g., boceprevir, telaprevir), azole antimycotics (e.g., ketoconazole, itraconazole, posaconazole, voriconazole), conivaptan, delavirdine, nefazodone Nimodipine plasma concentration can also be increased in the presence of moderate and weak inhibitors of CYP3A4. If nimodipine is concomitantly administered with these drugs, blood pressure should be monitored, and a reduction of the nimodipine dose may be necessary.

Moderate and weak CYP3A4 inhibitors include alprozalam, ameprenavir, amiodarone, aprepitant, atazanavir, cimetidine, cyclosporine, diltiazem, erythromycin, fluconazole, fluoxetine, isoniazid, oral contraceptives, quinuprestin/dalfopristin, valproic acid, and verapamil. A study in eight healthy volunteers has shown a 50% increase in mean peak nimodipine plasma concentrations and a 90% increase in mean area under the curve, after a one-week course of cimetidine at 1,000 mg/day and nimodipine at 90 mg/day. This effect may be mediated by the known inhibition of hepatic cytochrome P-450 (CYP) by cimetidine, which could decrease first-pass metabolism of nimodipine.

Grapefruit juice inhibits CYP3A4. Ingestion of grapefruit/grapefruit juice is not recommended while taking nimodipine.

7.3 CYP3A4 Inducers Nimodipine plasma concentration and efficacy may be significantly reduced when concomitantly administered with strong CYP3A4 inducers. Therefore, concomitant use of NYMALIZE with strong CYP3A4 inducers (e.g., carbamazepine, phenobarbital, phenytoin, rifampin, St. John's wort) should generally be avoided [see Warnings and Precautions (5.4) ] . Moderate and weak inducers of CYP3A4 may also reduce the efficacy of nimodipine. Patients on these should be closely monitored for lack of effectiveness, and a nimodipine dosage increase may be required.

Moderate and weak CYP3A4 inducers include, for example: amprenavir, aprepitant, armodafinil, bosentan, efavirnenz, etravirine, Echinacea, modafinil, nafcillin, pioglitazone, prednisone, rufinamide, and vemurafenib.

8.1 Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of NYMALIZE in pregnant women. In animal studies, oral administration of nimodipine during pregnancy resulted in adverse effects on development (increased embryofetal mortality, increased incidences of fetal structural abnormalities, decreased fetal growth) at doses equivalent to (rat) or less than (rabbit) those used clinically [see Data ] . In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

The background risk of major birth defects and miscarriage for the indicated population is unknown. Data Animal Data Nimodipine has been shown to have a teratogenic effect in two studies in rabbit. In one study, incidences of malformations and stunted fetuses were increased at oral doses of 1 mg/kg/day and 10 mg/kg/day administered throughout organogenesis but not at 3 mg/kg/day. In the second study, an increased incidence of stunted fetuses was seen at 1 mg/kg/day but not at higher doses (3 mg/kg/day and 10 mg/kg/day). The lowest effect dose in rabbits (1 mg/kg/day) is less than the recommended human dose (RHD) of 360 mg/day on a body surface area (mg/m 2 ) basis.

Nimodipine was embryotoxic, causing resorption and stunted growth of fetuses in rats at 100 mg/kg/day administered orally throughout organogenesis; this dose is approximately 3 times the RHD on a mg/m 2 basis. In two other studies in rats, nimodipine administered orally at 30 mg/kg/day throughout organogenesis and continued until sacrifice (day 20 of pregnancy or day 21 postpartum) was associated with higher incidences of skeletal variation, stunted fetuses, and stillbirths but no malformations; this dose is similar to the RHD on a mg/m 2 basis.