Metoprolol Pregnancy and Breast Feeding Warnings

Metoprolol is also known as: Lopressor, Toprol-XL

Overview

If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Metoprolol Succinate Extended-Release Tablets while you are pregnant. Metoprolol Succinate Extended-Release Tablets is found in breast milk. If you are or will be breast-feeding while you use Metoprolol Succinate Extended-Release Tablets, check with your doctor. Discuss any possible risks to your baby.

Metoprolol Pregnancy Warnings

Metoprolol has been assigned to pregnancy category C by the FDA. Animal studies have revealed decreased embryo and neonatal survival in rats at doses up to 22 times (on a mg/m2 basis) the daily dose of 200 mg in a 60 kg patient, although there was no evidence of impaired fertility or teratogenicity. There are no controlled data in human pregnancy. Metoprolol should only be given during pregnancy when benefit outweighs risk.

Metoprolol readily crosses the placenta. The maternal to fetal serum metoprolol concentration ratio is approximately 1:1. No teratogenic effects have been reported in human pregnancy. In a large study, the incidence of perinatal mortality was 2% of 57 hypertensive women who were treated with metoprolol alone, compared to 8% of 97 patients who were treated with hydralazine alone. No signs or symptoms of beta-blockade were noted in the fetuses or neonates. A case of a pregnant woman successfully treated with metoprolol for pheochromocytoma has been reported. Again, no signs or symptoms of beta-blockade were noted in the newborn. It is recommended that newborns who are exposed in utero to metoprolol should be carefully monitored for signs and symptoms of beta-blockade (bradycardia or hypotension) for at least 48 hours after birth. Incidentally, the plasma clearance (CL/F) of metoprolol is increased during pregnancy, averaging 362 mL/min/kg, compared to 82 mL/min/kg in the same patients postpartum.

Metoprolol Lactation Warnings

Metoprolol is excreted into human milk in very small quantities. Adverse effects on the nursing infant are unlikely. The American Academy of Pediatrics considers metoprolol to be compatible with breast-feeding.

Data from three lactating women who each were taking metoprolol up to 100 mg orally twice a day show that the mean area under the concentration versus time curve (AUC) in milk to AUC maternal serum ratio was 3.6, indicating concentration of metoprolol in human milk. Assuming ingestion of 75 mL of milk per meal, the infant's dose at the time of maximum maternal drug concentration would not exceed 0.05 mg, and would be considerably less at other times. The authors of this study recommended that, unless the nursing infant has impaired renal or hepatic function, breast-feeding need not be interrupted with ordinary doses of metoprolol. Nursing infants should be carefully observed for signs of beta-blockade, however.

Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Wolters Kluwer Health and Drugs.com is accurate, up-to-date, and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This drug information does not endorse drugs, diagnose patients, or recommend therapy. This drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug of drug combination is safe, effective, or appropriate for any given patient. Multum Information Services, Inc. does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. Copyright 2000-2008 Multum Information Services, Inc. The information in contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.