Dopaminergic drugs
Last reviewed: 23.04.2024
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Levodopa. Dioxyphenylalanine (DOPA or DOPA) is a biogenic substance formed in the body from tyrosine and is a precursor of dopamine, which in turn is converted into noradrenaline and then into adrenaline. Levodopa is well absorbed when taken orally, with the maximum concentration in the blood plasma created after 1-2 hours. It is allocated largely by the kidneys, less with feces.
The drug is administered orally during or after a meal. The initial dose is usually 0.25 g, every 2-3 days the dose is increased by 0.25 g to a daily dose of 3 g.
The drug reduces psychomotor and emotional reactions.
Studies have shown that levodopa, restoring the activity of the sympathetic nervous system, contributes to the faster disappearance of symptoms of heart failure and speeds up the reparative processes. After the course of treatment with levodopa, the excretion of dopamine increased by 3.4 times, and the excretion of norepinephrine by 65%, which indicates a significant increase in the biosynthesis intensity of both dopamine and norepinephrine. The adrenaline excretion remained unchanged. Accordingly, the norepinephrine / adrenaline ratio is increased by a factor of 1.5.
Levodopa stimulates the synthesis of noradrenaline, thereby contributing to a faster disappearance of symptoms of heart failure. Identical patterns are observed in a number of complications of pregnancy and childbirth - the ratio of noradrenaline / adrenaline is violated, and therefore the use of levodopa is effective in preventing the weakness of labor.
In experiments on rats, mice and rabbits, there was no embryophototoxic or teratogenic effect, even in doses of 75-150-300 mg / kg, the drug administered to rats on days 6-15 of pregnancy did not adversely affect the fetus.
Levodopa is successfully used in doses of 0.25-2 g / day in complex therapy for miscarriage.
When using the drug, various side effects can occur in the form of dyspeptic phenomena (nausea, vomiting, loss of appetite), orthostatic hypotension, arrhythmia, headache, involuntary movements, anxiety, tachycardia.
Form release: capsules and tablets of 0.25 and 0.5 g in packages of 100 and 1000 pieces.
Methyldofa (methyldopoum, dopegit). The predecessor of the "false" adrenergic mediator of a-methylnoradrenaline, the inhibitor of dofa-decarboxylase, methyldopa, like clonidine, inhibits synaptic impulses and causes a decrease in blood pressure. Hypotension is accompanied by a slowdown in heart rate, a decrease in cardiac output and peripheral resistance.
Methyldopa is used as an antihypertensive agent that reduces peripheral vascular resistance and is effective in hypertensive disease. The drug does not have a stronger hypotensive effect than sympatholytic drugs, but it is better tolerated and causes fewer side effects. Therefore, it is increasingly used in the treatment of hypertension in pregnancy, childbirth, the postpartum period, without having a negative impact on the mother's body, the condition of the fetus and the newborn. It is not yet clear whether methyldopa passes through the placental barrier, but its use in the last trimester of pregnancy has not revealed fetoembritoxic or teratogenic effects.
Assign methyldopa inward in the form of tablets of 0.25 g. Usually start with 0.25-0.5 grams per day, then increase the dose to 0.75-1 g, and with insufficient effect - up to 1.5-2 g in day.
It should be taken into account that the effect of methyldof is short and after the drug is discontinued the arterial pressure rises again.
Product: tablets of 0.25 grams in a package of 50 pieces.
[