active substance: methyldopa;
1 tablet contains 250 mg of methyldopa (in the form of sesquihydrate 282 mg);
Dopegyt excipients: magnesium stearate, stearic acid, sodium starch (type A), ethyl cellulose, corn starch, talc.
Dopegyt Dosage form
Basic physical and chemical properties: white or grayish-white color, round, flat, beveled tablets, smooth on one side, with “DOPEGYT” engraving on the other, odorless or almost odorless.
Antiadrenergic drugs of central action.
ATX code С02А В01.
Dopegit (methyldopa) is a centrally acting antihypertensive drug. Its mechanism of action is not fully understood. Once in the central nervous system, the drug has a hypotensive effect due to its active metabolites (alpha-methyl-epinephrine and alpha-methyl-norepinephrine). By stimulating the alpha2-adrenergic receptors of the brain stem neurons, it reduces the tone of the sympathetic nervous system.
Moderately reduces plasma renin levels and total peripheral vascular resistance.
By suppressing the enzyme dopa-decarboxylase, it reduces the synthesis of norepinephrine, dopamine, serotonin and tissue concentration of norepinephrine and adrenaline.
Methyldopa has no direct effect on heart function. Minute blood volume changes little. Does not cause reflex tachycardia, increases the glomerular filtration rate and renal blood flow, as well as the filtration fraction. Reduces the heart rate somewhat. Effectively lowers blood pressure in the supine and standing position, rarely causes orthostatic hypotension.
After oral administration, about 50% of the drug is absorbed in the gastrointestinal tract. Plasma protein binding is insignificant – up to 20%. The maximum decrease in blood pressure occurs 4-6 hours after taking the drug and lasts for 12-24 hours. After repeated administration of the drug, the maximum decrease in blood pressure is observed within 2-3 days. After discontinuation of the drug, blood pressure returns to its previous level within 1-2 days.
Methyldopa is extensively metabolized, mainly in the liver. Its active metabolite, alpha-methylnorepinephrine, is derived from central adrenergic neurons.
In addition, many other metabolites are known that are excreted in the urine.
Approximately 70% of methyldopa is excreted in the urine as methyldopa or its sulfoconjugative. The rest is excreted in the feces in the form of methyldopa. With normal renal function, the elimination half-life is 1.7 hours. Complete elimination of the drug occurs after 36 hours.
Methyldopa is removed from the body by dialysis. With 6-hour hemodialysis, 60% of the absorbed methyldopa can be removed from the circulation, with peritoneal dialysis – 22-39%.
Methyldopa crosses the placental barrier and into breast milk.
Special group of patients
In renal failure, excretion of methyldopa is slowed down according to the degree of kidney damage. In severe kidney damage (without dialysis), the half-life of methyldopa is 10 times less than under normal conditions.
Hypersensitivity reactions to the components of the drug; liver dysfunction associated with previous methyldopa therapy; acute liver dysfunction (including acute hepatitis and active cirrhosis); combined use with MAO inhibitors (MAO) depression of pheochromacytoma; porphyria.
Interaction with other medicinal products and other types of interactions
Dopegit should be used with extreme caution in combination with any of the following drugs:
sympathomimetics (possibly increased vasopressor effect);
oral iron preparations (the bioavailability of methyldopa may decrease);
non-steroidal anti-inflammatory drugs;
The antihypertensive effect of methyldopa is enhanced when used with other antihypertensive drugs, anesthetics.
With simultaneous use with antihypertensive drugs, idiosyncrasy may occur.
Methyldopa and the following drugs may alter each other’s effects:
lithium (possibly increased toxicity of lithium);
levodopa [decrease in antiparkinsonian effect, increase in adverse effects on the central nervous system (CNS)];
alcohol and drugs that depress the central nervous system (the depressing effect on the central nervous system is enhanced);
anticoagulants (the anticoagulant effect increases, the risk of bleeding);
bromocriptine (may adversely affect the concentration of prolactin).