Methyldopa

Pharmacological action: 1 Methyldopa is an inhibitor of aromatic amino acid decarboxylase. 2 Only the levorotatory isomer of methyldopa has antihypertensive activity in humans, and the racemic body (DL-?-methyldopa) requires twice the dose to achieve the same antihypertensive effect. Its antihypertensive effect may be through its active metabolite ?-methylnorepinephrine stimulating the inhibitory ?-adrenaline receptors and pseudo-neurotransmitters of the central nervous system, reducing plasma renin activity, and thus reducing arterial blood pressure. 3 Methyldopa can reduce the concentration of 5-hydroxytryptamine, dopamine, norepinephrine, and methylepinephrine in tissues. 4 Methyldopa has no direct effect on cardiac function, and usually does not reduce glomerular filtration rate, renal blood flow, and filtration fraction. 5 Cardiac output remains unchanged at normal heart rate, and some patients experience a slow heart rate. 6 Plasma renin activity decreases during treatment. 7 Methyldopa can reduce supine and standing blood pressure, and postural hypotension rarely occurs. Hypotension during daytime exercise is rare. Carcinogenicity, mutagenicity, reproductive toxicity: Mice and rats were given methyldopa 1800mg/kg/day and 240mg/kg/day (equivalent to 30 times and 4 times the maximum human dose, respectively), and there was no carcinogenic effect for 2 years. In the Ames test, methyldopa did not increase chromosomal aberrations and sister chromatid exchanges in the ovarian germ cells of Chinese hamsters. Male and female rats were given methyldopa 100mg/kg/day, and no fertility was affected. Methyldopa reduces sperm count, sperm motility, and late sperm count. Male rats were given methyldopa 200 and 400mg/kg/day (calculated by body surface area, about 0.5 times and 1 times the maximum daily dose for humans), and the male fertility index decreased. Mice were given methyldopa 1000mg/kg orally, rabbits 200mg/kg, and rats 100mg/kg (calculated by body surface area, equivalent to 1.4 times, 1.1 times, and 0.2 times the daily dose for humans, respectively), and no harmful effects were observed on the fetus.

The main ingredients of this product are: Methyldopa

Used for moderate, severe or malignant hypertension, especially renal hypertension.

1. Common dosage for adults: Oral, 250 mg/time, divided into 2~3 times/day. Adjust the dose once every 2 days to achieve the desired therapeutic effect. Generally, increase the dose at night to reduce the excessive sedative effect of the drug. If used in combination with thiazide diuretics, the dose needs to be reduced, and the initial dose is controlled at 500 mg/day, but the dose of diuretics can remain unchanged. The maintenance dose is 0.5-2g/day, divided into 2-4 oral doses, and the maximum dose should not exceed 3g/day. Because methyldopa has a short duration of action, other antihypertensive treatments should be given within 48 hours after discontinuation of the drug. Drug resistance may occur after 2-3 months of medication, and the efficacy can be restored by giving diuretics. 2. Common dosage for children: Oral, 10 mg/Kg per day, or 300 mg/m2 per body surface area, divided into 2~4 oral doses. Adjust the dose once every 2 days to achieve the required therapeutic effect.

1. Sedation, headache and fatigue occur more often when starting medication and increasing dosage, and are usually transient. 2. Common symptoms include: lower limb edema and dry mouth caused by water and sodium retention. 3. Less common symptoms include: drug fever or eosinophilia, changes in liver function (possibly immune or allergic), mental changes (depression or anxiety, sleep talking, insomnia), decreased sexual function, diarrhea, breast enlargement, nausea, vomiting, and fainting. 4. Occasionally, angina pectoris and heart failure may be aggravated. 5. Rare: prolonged carotid sinus sensitivity and postural hypotension, weight gain, sinus bradycardia, liver function damage, pancreatitis, colitis sialadenitis, tongue pain or black tongue, constipation, abdominal distension, flatulence, hyperprolactinemia, bone marrow suppression, thrombocytopenia, hemolytic anemia, leukopenia, antinuclear antibodies, LE cells, positive rheumatoid factor, positive direct antiglobulin (Coombs) test, myocarditis, pericarditis, vasculitis, lupus-like syndrome, Parkinson's disease, paralysis agitans, slow reaction, involuntary chorea, symptoms of cerebrovascular insufficiency, mental confusion such as dreaminess, sedation, weakness, paresthesia, increased blood urea nitrogen (BUN), joint pain, which may be accompanied by joint swelling, muscle pain, nasal congestion, epidermal necrosis, rash, amenorrhea, male breast development, lactation. 6. Rare: granulocytopenia, which returns to normal after discontinuation of the drug. Fatal hepatocyte necrosis.

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Hunan Xiangyikang Pharmaceutical Co., Ltd.

• Founded in:

  2009-01-05

• Address:

  Datong Lake District, Yiyang City, Hunan Province

• Tax NO.:

  914309006828327274

• Registered Funds:

  10 million yuan

• Email:

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