Methyldopa Pharmacology


About Methyldopa
Centrally acting Alpha-2 agonist ,a phenylalanine derivative, Antihypertensive (pregnancy-induced hypertension).
Mechanism of Action of Methyldopa
Methyl dopa gets metabolized in the adrenergic neurons to alpha methyl nor adrenaline which acts centrally by stimulating alpha 2 adrenergic receptors in the vasomotor centre to decrease efferent sympathetic activity and total peripheral resistance. It also inhibits renin release from the kidneys and has some direct action on blood vessels. Since methyl dopa serves as an alternate substrate to L-aromatic amino acid decarboxylase it ultimately decrease the concentration of Dopamine, Nor-adrenaline, Epinephrine and Serotonin in the CNS and periphery.

Pharmacokinets of Methyldopa
Absorption: About half of the drug administered is absorbed orally,
Distribution: Widely distributed, Metabolism: Extensively metabolized in liver & intestinal cells, Excretion: Excreted mainly through urine and some amount is excreted through faeces

Onset of Action for Methyldopa
4 to 6 hours
Duration of Action for Methyldopa
1 to 3 days
Half Life of Methyldopa
Side Effects of Methyldopa
2.Mental depression
3.Dryness of mouth, eyes & nose
4.Cognitive impairment
9.Electrolyte imbalance
10.Postural hypotension
11.Weight gain
15.Drug fever
16.Haemolytic anaemia
Contra-indications of Methyldopa
1.Hypersensitivity to the drug
2.Hepatitis, Cirrhosis or other hepatic disorders
5.Postural hypotension
7.Concurrent administration with MAO inhibitors

Special Precautions while taking Methyldopa
1.Renal impairment
2.Hepatic impairment
3.Haemolytic anaemia
4.Some individuals may show +ve direct coomb`s test
6.Asses blood count and liver function
7.Avoid driving or other jobs requiring mental concentration

Pregnancy Related Information
May be used.
Old Age Related Information
Use with caution.
Breast Feeding Related Information
May be used.
Children Related Information
Use with caution
Indications for Methyldopa
Interactions for Methyldopa
Haloperidol: Adverse mental symptoms and high incidence of sedation.
Levodopa: Effects of levodopa potentiated.
Corticosteroids & Carbenoxolone: Antagonism of hypotensive effects.
Propranolol: Paradoxical hypertensive effect.
Diuretics: Enhanced hypotensive effect.
Nitrates: Enhanced hypotensive effects.
Sympathomimetics: Methyldopa potentiates the pressor effects.
Antipsychotics: Increased risk of extrapyramidal symptoms.
Tolbutamine: Hypoglycaemic effects enhanced.
Sex hormones: Antagonise hypotensive effect.
Lab tests: Interferes with tests for urinary-uric acid by phosphotungstate method. Serum creatinine by alkaline picrate method.
AST by calorimetric methods. False high levels of urinary catecholamines occur interfering with diagnosis of pheochromocytoma.
Typical Dosage for Methyldopa
250mg to 500mg orally 12hourly or 6hourly or
250mg to 500mg I.V. four times daily
10mg/kg/day orally 12hourly or 6hourly or 20 to 40mg/kg/day I.V. in four divided doses

Schedule of Methyldopa
Storage Requirements for Methyldopa
Store at room temperature in a well closed container. Protect from heat and light. Keep out of the reach of children.
Effects of Missed Dosage of Methyldopa
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose
Effects of Overdose of Methyldopa
Treatment is supportive and symptomatic. After 4hours of drug use empty the stomach by induced emesis & gastric lavage. Administer activated charcoal. Perform haemodialysis if required.

Home Delivery for Methyldopa in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including methyldopa.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for methyldopa and other medicines and health products. Home delivery services for methyldopa may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take methyldopa only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for methyldopa before they complete the sale. You can get this information while placing the order for methyldopa with the pharmacy.

Methyldopa is a generic medicine name and there are several brands available for it. Some of the brands for methyldopa might be better known than methyldopa itself. If the pharmacy that's willing to deliver medicines to your home doesn't have methyldopa in stock, you can ask for one of the branded alternatives for methyldopa.