Methyldopa (methyldopa)

Dosage of methyldopa must be adjusted according to the patient's blood pressure response and tolerance. Adverse effects such as drowsiness may be minimized by starting dosage increases in the evening or by giving a larger dose at bedtime than in the morning. Geriatric patients may respond to smaller doses of methyldopa.

Patients with impaired renal function may respond to smaller doses of methyldopa.

Methyldopa is administered orally; methyldopate hydrochloride is administered by IV infusion. IM or subcutaneous administration of methyldopate hydrochloride is not recommended because of unpredictable absorption.

Methyldopate hydrochloride IV infusions are prepared by adding the required dose of the drug to 100 mL of 5% dextrose injection. Alternatively, the required dose may be administered in 5% dextrose injection in a concentration of 100 mg/10 mL. The IV infusion should be administered slowly over a period of 30-60 minutes. ADD-Vantage(R) vials labeled as containing 50 mg/mL of methyldopate hydrochloride should be diluted and administered according to the manufacturer's directions. Vials containing solutions of methyldopate hydrochloride for injection and reconstituted solutions of the drug should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

No dosing information is available for this tab.

No dosing information is available for this tab.

There is no enhanced messaging for this drug.

There are no contraindication interactions for this drug.

There are no severe interactions for this drug.

There are no moderate interactions for this drug.

There is no enhanced messaging for this drug.

There are no contraindication contraindications for this drug.

There are no severe contraindications for this drug.

There are no moderate contraindications for this drug.

There is no enhanced messaging for this drug.

There are no severe adverse reactions for this drug.

There are no less severe adverse reactions for this drug.

No enhanced messaging available.

No enhanced messaging available.

Reproduction studies in mice, rabbits, and rats using oral methyldopa in dosages of 1000, 200, and 100 mg/kg, respectively, have not revealed evidence of harm to the fetus. These dosages are 16.6, 3.3, and 1.7 times, respectively, the maximum daily human dosage when compared on the basis of body weight and 1.4, 1.1, and 0.2 times, respectively, the maximum daily human dosage when compared on the basis of body surface area.

Methyldopa has been used for many years in the management of hypertension in pregnant women, and the drug is generally considered safe for mother and fetus when used in association with careful prenatal management. Uteroplacental blood flow and fetal hemodynamics have been reported to be stable during therapy with the drug. Although no teratogenic effects have been reported, the possibility that methyldopa may cause fetal injury (e.g., secondary to reduced placental blood flow or fetotoxicity) cannot be excluded.

In neonates born to women treated with methyldopa, systolic blood pressure may be decreased during the first 2-3 days after delivery; in some neonates, tremors have also been reported. Studies to date, including a long-term follow-up study, of children born to women who received methyldopa during pregnancy have not revealed evidence of substantial adverse effects of the drug on the offspring; however, in the longest follow-up study, treatment with methyldopa was associated with a smaller head circumference (without an apparent effect on intelligence quotient) in male offspring of those women whose therapy was initiated between 16 and 20 weeks' gestation. At 4 years of age, the developmental delay commonly seen in children born to hypertensive mothers was less evident in those whose mothers received methyldopa during pregnancy than in those whose mothers were untreated. Children born to mothers receiving methyldopa scored consistently higher on indices of intellectual and motor development than children born to untreated hypertensive mothers; however, these differences were not apparent by 7.5 years of age.

Methyldopa should be used during pregnancy only when clearly needed. In addition, excessive reduction in blood pressure should be avoided, and a conservative approach to treatment generally should be followed. (See Hypertension during Pregnancy under Uses: Hypertension.)

Since methyldopa is distributed into milk, the drug should be used with caution in nursing women; the possibility of adverse effects on a nursing infant cannot be excluded. The extent to which methyldopa distributes into milk has not been clearly established, but the amount of drug a nursing infant would ingest is believed to be too small to be clinically important; however, if a woman receiving methyldopa breastfeeds, the infant (particularly if preterm) should be monitored for potential systemic effects of the drug (e.g., decreased respiration, blood pressure, or alertness).

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