Generic name: methyldopa

Brand names: Aldomet, Methyldopa

Molecular formula: C10H11N2O2

Molecular weight: 185.20 g/mol

Aldomet is a medication used to treat high blood pressure. It is also known as methyldopa. This medication works by decreasing the amount of norepinephrine and epinephrine in the body. This results in a decrease in blood pressure. Aldomet is available as a tablet, capsule, or liquid. It is usually taken two to four times per day with food. Some common side effects of this medication include dizziness, headache, and fatigue. If these side effects occur, they usually improve with time.

Aldomet

Pharmacokinetics

Methyldopa is rapidly and completely absorbed from the gastrointestinal tract. It is widely distributed into tissues, with highest concentrations in the liver, kidney, heart, and lungs. Methyldopa crosses the blood-brain barrier and placenta. It is metabolized in the liver to alpha-methylnorepinephrine and beta-methylnorepinephrine. These metabolites are excreted in the urine. The elimination half-life of methyldopa is 8-12 hours.

Modes of action

Methyldopa decreases sympathetic nerve outflow from the central nervous system by stimulation of central alpha2 adrenergic receptors. This results in a decrease in heart rate, myocardial contractility, and peripheral vascular resistance. The decrease in blood pressure is gradual and usually occurs within 2 weeks of therapy. Methyldopa also has direct inhibitory effects on smooth muscle, which contribute to its antihypertensive effect.

Clinical Uses

Methyldopa is used for the treatment of hypertension. It may be used alone or in combination with other antihypertensive agents. Methyldopa is also effective in the treatment of gestational hypertension and preeclampsia.

Side Effects

The most common side effects of methyldopa are dizziness, headache, and fatigue. These side effects usually improve with time. Other common side effects include dry mouth, constipation, nausea, and vomiting. If these side effects occur, they usually improve with time. This medication may also cause drowsiness. Do not drive or operate heavy machinery if you experience this side effect. This medication may also cause an increase in liver enzymes. If you experience this side effect, speak to your doctor.

Drug Interactions

Methyldopa may interact with other medications. Tell your doctor all medications and supplements you use. Methyldopa should be used with caution in elderly patients; they may be more sensitive to the effects of the drug. This medication is not recommended for use in children.

Contraindications

Aldomet is contraindicated in patients with hypersensitivity to methyldopa or any other ingredient in the formulation. This medication is also contraindicated in patients with severe liver disease or pheochromocytoma.

Warnings

Methyldopa may cause drowsiness. Do not drive or operate heavy machinery if you experience this side effect. This medication may also cause an increase in liver enzymes. If you experience this side effect, speak to your doctor. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you are pregnant or planning a pregnancy, speak to your doctor about the risks of taking this medication.

Tell your doctor if you have or have ever had liver disease, kidney disease, or pheochromocytoma (a tumor of the adrenal gland). Methyldopa should be used with caution in patients with diabetes mellitus; this medication may cause an increase in blood sugar levels. Methyldopa should be used with caution in patients with a history of depression; this medication may worsen depression. This medication may cause drowsiness. Do not drive or operate heavy machinery if you experience this side effect.

This medication is not recommended for use during pregnancy. If you are pregnant or planning a pregnancy, speak to your doctor about the risks of taking this medication. This medication passes into breast milk. Breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.

Methyldopa may interact with other medications. Tell your doctor all medications and supplements you use. This medication should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Methyldopa crosses the placenta and has been associated with fetal toxicity, including bradycardia, hypotension, and lethargy in newborns. There are no adequate and well-controlled studies of methyldopa in pregnant women. This medication should be used during breastfeeding only if the potential benefit justifies the potential risk to the infant. Methyldopa is excreted in human milk and has been associated with sedation and irritability in nursing infants. If methyldopa is used during breastfeeding, the infant should be monitored for these effects.

Dosage and Administration

Aldomet is available as 250 mg and 500 mg tablets. The usual starting dose is 250 mg two or three times daily. The dose may be increased by 250 mg every 2-3 days until the desired blood pressure lowering effect is achieved or a maximum dose of 2000 mg daily is reached.

The recommended target dose range is 1000-3000 mg/day given in two or three divided doses. Once the optimum response has been determined, a maintenance dosage should be established. The usual maintenance dosage range is 250-1000 mg/day given in two or three divided doses.

Dosage adjustments may be necessary in elderly patients or in patients with hepatic impairment. In general, it is not necessary to adjust the dosage in patients with renal impairment.

Aldomet should be taken with food or milk to reduce the incidence of gastrointestinal side effects.

Aldomet should be used with caution in patients with diabetes mellitus, depression, or kidney disease.

Overdose

Symptoms of overdose include hypotension, tachycardia, and drowsiness. Treatment is supportive and symptomatic. Gastric lavage and activated charcoal may be useful in early stages of toxicity. If hypertension persists, intravenous labetalol or oral nifedipine may be used. Dialysis is not effective.