Methyldopa injection dosage and administration

Methyldopa
Methyldopa tablet® FDA Package Insert
Indications and Usage
Dosage and Administration
Contraindications
Warnings
Precautions
Adverse Reactions
Drug Interactions
Use in Specific Populations
Overdosage
Description
Clinical Pharmacology
Nonclinical Toxicology
How Supplied/Storage and Handling
Labels and Packages
Methyldopa injection® FDA Package Insert
Indications and Usage
Dosage and Administration
Contraindications
Warnings
Precautions
Adverse Reactions
Drug Interactions
Use in Specific Populations
Overdosage
Description
Clinical Pharmacology
Nonclinical Toxicology
How Supplied/Storage and Handling
Labels and Packages
Clinical Trials on Methyldopa
ClinicalTrials.gov

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Abdurahman Khalil, M.D. [2]

Dosage and Administration

Methyldopate HCl Injection when given intravenously in effective doses, causes a decline in blood pressure that may begin in four to six hours and last 10 to 16 hours after injection.

Add the desired dose of Methyldopate HCl Injection to 100 mL of Dextrose Injection 5%, USP. Alternatively the desired dose may be given in 5% dextrose in water in a concentration of 100 mg/10 mL. Give this intravenous infusion slowly over a period of 30 to 60 minutes.

Adults: The usual adult dosage intravenously is 250 mg to 500 mg at six hour intervals as required. The maximum recommended intravenous dose is 1 gram every six hours.

When control has been obtained, oral therapy with tablets may be substituted for intravenous therapy, starting with the same dosage schedule used for the parenteral route. The effectiveness and anticipated responses are described in the circular for tablets.

Since methyldopate has a relatively short duration of action, withdrawal is followed by return of hypertension usually within 48 hours. This is not complicated by an overshoot of blood pressure.

Occasionally tolerance may occur, usually between the second and third month of therapy. Adding a diuretic or increasing the dosage of methyldopa frequently will restore effective control of blood pressure. A thiazide may be added at any time during methyldopa therapy and is recommended if therapy has not been started with a thiazide or if effective control of blood pressure cannot be maintained on 2 grams of methyldopa daily.

Methyldopa is largely excreted by the kidney and patients with impaired renal function may respond to smaller doses. Syncope in older patients may be related to an increased sensitivity and advanced arteriosclerotic vascular disease. This may be avoided by lower doses.

Pediatric Patients: The recommended daily dosage is 20 to 40 mg/kg of body weight in divided doses every six hours. The maximum dosage is 65 mg/kg or 3 grams daily, whichever is less. When the blood pressure is under control, continue with oral therapy using tablets in the same dosage as for the parenteral route. (see PRECAUTIONS, Pediatric Use.) Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.