The mechanism of action of Methyldopa BP 250mg is probably due to its metabolite alpha-methyInoradrenaline, which lowers arterial pressure by stimulation of central inhibitory alpha-adrenergic receptors, false neurotransmission, and/or reduction of plasma renin activity, Methyldopa BP 250mg reduces both standing and supine blood pressure. Variations in dumai blood pressure, symptomatic postural hypotension and exercise hypotension rarely occur. Careful adjustment of dosage avoids morning hypotension and does not affect the control of afternoon blood pressure. Methyldopa BP 250mg has no direct effect on cardiac heart function, and does not reduce filtration fraction, renin blood flow or glomerular filtration rate. Methyldopa BP 250mg may be given with caution to patients with renal dysfunction. Indications: Methyldopa BP 250mg tablets are indicated for the treatment of hypertension.
Adults: The innitial dose of Methyldopa BP 250mg tablets is usually 250mg two to three times daily for two days. The dose may be increased at intervals of not less than two days by an additional 250-500mg daily until satisfactory control is achieved. The maximum recommended daily dosage is 3g. Methyldopa BP 250mg is mainly excreted by the kidneys therefore patients with renal dysfunction may respond well to lower doses. The requirement of Methyldopa BP 250mg may be reduced by giving a thiazide diuretic concurrently: downward adjustment of dosage should likewise be made at intervals of less than 48 hours, When patients are on other hypotensive agents and it is desired to change them over to Methyldopa BP 250mg, drug interactions must be carefully watched for When Methyldopa BP 250mg is given to patients on other antihypertensives the dose of these agents has to be adjusted to effect a smooth transition. Methyldopa BP 250mg may be used concurrently with Amiloride, Hydrochlorothiazide and beta-blocking agents. Elderly: The initial dose should not exceed 250mg daily. This should be increased slowly as required but not to exceed a maximum daily dose of 2g.
The most frequent side-effect is sedation which may occur even at the starting dose level-
It usually subsides after an effective maintenance dosage has been established. Depression may also occur and corrective treatment with tricyclic antidepressants may antagonise the therapeutic effect of Methyldopa BP 250mg.Serious side-effects due to Methyldopa BP 250mg are rare and this agent is welt tolerated. The following reactions have been reported: Allergic: Drug-related fever and lupus-like syndroms, myocarditis, pericarditis. Cardiovascular: Bradycardia, prolonged carotid sinus hypersensitivity, aggravation of angina pectoris, orthostatic hypotension and oedema. Centra nervous system; Sedation, asthenia or weakness, headache paraesthesia, parkinsonism, involuntary choreoathetotic movements, Bell’s palsy, psychic disturbances, dizziness, light-headedness and symptoms of cerebrovascular insufficiency. Dermatological Rash as in eczema or lichenoid eruption, toxic epidermal necrolysis Gastro-intestinal: Nausea, vomiting, constipation, distention, flatus, colitis,diarrhoea,dry mouth, sore or black, tongue, sialadenitis and pancreatitis. Hepatic; Liver disorders such as abnormal fiver function tests, hepatitis and jaundice. Hematologic: Positive Coombs' test, bone marrow depression, leukopenia, haemolytic anaemia, granulocytopenia, thrombocytopenia, positive tests to LE cells, antinuclear antibody and rheumatoid factor. Miscellaneous: Myalgia, mild arthralgia, decreased libido, nasal stuffiness, rise in blood urea, gynaecomastia, breast enlargement, hyperprolactinemia, lactation, amenorrhoea, failure in ejaculation and impotence. Precautions Methyldopa BP 250mg should be used with caution in patients with impaired kidney or liver function or with a history of haemolytic anaemia of liver disease. Care is also advisable in patients with parkinsonism. Methyldopa BP 250mg is not recommended for pheochromocytoma. It has been reported to aggravate porphyria. It is advisable to make periodic blood counts and to perform liver-function tests at intervals during the first 6 to 12 weeks of treatment or if the patient develops an unexplained fever. Patients taking Methyldopa BP 250mg may produce a positive response to a direct Coombs' test: if blood transfusion is required, prior knowledge of a Coombs' test reaction will aid cross matching. Methyldopa BP 250mg may cause sedation. If affected do not drive or operate machinery. Pregnancy: Although no obvious teratogenic effects have been reported the possibility of foetal injury cannot be excluded and the drug should only be used in women who are or may become pregnant, if there are no safer alternatives and if the degree of hypertension carries risk for the mother or child,
Store below 25℃. Protect from moisture and light. Keep out of reach of children.