Methyldopa (Methyldopa)
Overview of Methyldopa
Methyl dopa is a widely used oral antihypertensive agent. Methyldopa is analog of L-dopa. Chemically Methyldopa is identified as L-3-(3, 4-dihydroxyphenyl)-2-methylalanine. After crossing the blood-brain barrier, Methyldopa is decarboxylated to produce alpha-methylnorepinephrine. This metabolite stimulates central inhibitory alpha-adrenergic receptors, thereby reducing peripheral resistance and lowering blood pressure.it also may act as a false transmitter, thereby exerting a direct effect on peripheral sympathetic nerves. Blood pressure decreases are greatest when the patient is standing but are also significant when the patient is supine. Postural hypotension has been reported in patients receiving it. It can cause sodium and fluid retention, and tolerance can develop during long-term therapy.
Indication of Methyldopa
Methyldopa is primarily indicated in conditions like Hypertension, Hypertension in pregnancy, Hypertensive emergencies, Primary hypertension, Renal hypertension, and can also be given in adjunctive therapy as an alternative drug of choice in Postmenupausal flushing.
Contraindication of Methyldopa
Methyldopa is contraindicated in conditions like Hepatic disease,Postural hypotension,Hypersensitivity.
Side Effects of Methyldopa
The severe or irreversible adverse effects of Methyldopa, which give rise to further complications include Thrombocytopenia, Pancreatitis, Granulocytopenia, Depression, Acute colitis.,Methyldopa produces potentially life-threatening effects which include Hemolytic anemia, Hepatitis, Myocarditis. which are responsible for the discontinuation of Methyldopa therapy.,The signs and symptoms that are produced after the acute overdosage of Methyldopa include Bradycardia, Hypotension, Coma, Dry mouth, Hypothermia, Dizziness, Weakness.,The symptomatic adverse reactions produced by Methyldopa are more or less tolerable and if they become severe, they can be treated symptomatically, these include Dizziness, Diarrhea, Fever, Skin rashes, Dry mouth, Sedation, Impotence, Loss of libido, Nasal congestion, Light headedness, Galactorrhea, Eosinophilia, Failure of ejaculation.
Precautions of Methyldopa
The patient should have Hemoglobin, Hemocrit and ESR assessed before and during Methyldopa therapy because of the risk of the hemolytic anemia. The drug should be used with caution in the patient with hemolytic anemia and autoimmune disease, if present, discontinue the therapy. The drug should be used with caution in the patient with hepatic or renal impairment, pheochromocytoma, and cardiovascular or cerebrovascular insufficiency, major Depression. Methyldopa can cause the sedation, so the patient should be warned that impaired physical coordination and /or reduced mental alertness can affect their ability to operate machinery or drive a vehicle.