dosage changes. Adjust warfarin dosage based on INR and clinical response. Once a stable INR is documented, the INR can be monitored at the intervals otherwise recommended based on the indication for anticoagulation and co-existing conditions.
Zafirlukast: Zafirlukast inhibits the CYP3A4 isoenzymes and should be used cautiously in patients stabilized on drugs metabolized by CYP3A4, such as simvastatin.
Zileuton: Zileuton is metabolized by the cytochrome P450 isoenzyme 3A4. Although administration of zileuton with other drugs metabolized by CYP3A4 has not been studied, zileuton may inhibit CYP3A4 isoenzymes. Zileuton could potentially compete with other CYP3A4 substrates, including simvastatin.
Zonisamide: Zonisamide is a weak inhibitor of P-glycoprotein (P-gp), and simvastatin is a substrate of P-gp. There is theoretical potential for zonisamide to affect the pharmacokinetics of drugs that are P-gp substrates. Use caution when starting or stopping zonisamide or changing the zonisamide dosage in patients also receiving drugs which are P-gp substrates.
PREGNANCY AND LACTATION
Pregnancy
Ezetimibe; simvastatin is classified as FDA pregnancy category X and is contraindicated for use during pregnancy, because of the potential effects of HMG-CoA reductase inhibitors on cholesterol pathways and the potential for fetal harm. Cholesterol and other products of the cholesterol biosynthesis pathway are essential components for fetal development, including synthesis of steroids and cell membranes. Treatment should be immediately discontinued as soon as pregnancy is recognized. In a prospective review of about 100 pregnancies in women exposed to simvastatin or another structurally related HMG-CoA reductase inhibitor, the incidence of congenital anomalies, spontaneous abortions, and fetal deaths/stillbirths did not exceed what would be expected in the general population. However, atherosclerosis is a chronic process and the discontinuation of lipid-lowering drugs during pregnancy should have little impact on the outcome of long-term therapy of primary hypercholesterolemia. If the patient becomes pregnant while taking this drug, Ezetimibe; Simvastatin should be discontinued immediately and the patient should be apprised of the potential hazard to the fetus. Ezetimibe; Simvastatin should only be administered to females of child-bearing potential, including adolescents at least 1 year post-menarche, when such patients are highly unlikely to conceive and have been informed of the potential hazards. Females should be counseled regarding appropriate methods of contraception while on therapy.
Ezetimibe; simvastatin should be avoided during breast-feeding. Cholesterol and other products of the cholesterol biosynthesis pathway are essential components for infant growth and development, including synthesis of steroids and cell membranes. HMG-CoA reductase inhibitors decrease the synthesis of cholesterol and possibly other products of the cholesterol biosynthesis pathway; therefore, ezetimibe; simvastatin is contraindicated for use during breast-feeding. If pharmacotherapy is necessary in the nursing mother, a nonabsorbable resin such as cholestyramine, colesevelam, or colestipol should be considered. These agents do not enter the bloodstream and thus will not be excreted during lactation. However, resins bind fat-soluble vitamins and prolonged use may result in deficiencies of these vitamins in the mother and her nursing inf |
