Description of the medicine: Papaverine (Papaverinum)
Alkaloid contained in opium. Currently obtained synthetically. Available in the form of papaverine hydrochloride (Paraverini hydrochloridum).
By its chemical structure, it is 6, 7-dimethoxy-1- (3, 4-dimethoxybenzyl) -isoquinoline hydrochloride.
White crystalline powder with a slightly bitter taste. Slowly soluble in water (1:40), little in alcohol. Aqueous solutions (pH 3, 0 - 4, 5) are sterilized at + 100 ° C for 30 minutes.
Papaverine is a myotropic antispasmodic. It lowers the tone and reduces the contractile activity of smooth muscles and therefore has a vasodilating and antispasmodic effect.
In large doses, it reduces the excitability of the heart muscle and slows down intracardiac conduction.
The mechanism of action of papaverine is not clear enough. In recent years, it has been established that it is an inhibitor of the phosphodiesterase enzyme and causes intracellular accumulation of cyclic 3 ', 5'-adenosine monophosphate (see Theophylline).
The accumulation of cAMP ultimately leads to a violation of contractility of smooth muscles and their relaxation in spastic conditions.
The effect on the central nervous system is poorly expressed, only in large doses does it have a certain sedative effect.
Papaverine is widely used as an antispasmodic for smooth muscle spasms of the abdominal organs (with pylorospasm, cholecystitis, spastic colitis, urinary tract spasms), bronchi (usually in combination with other bronchodilators), as well as for peripheral vascular spasms (endarteritis, etc.) and cerebral vessels.
Previously, papaverine was relatively widely used orally for the prevention of angina attacks. The drug has some effect, but at present, more effective antianginal drugs are used for this purpose.
Sometimes papaverine is used parenterally (under the skin, intramuscularly, rarely in a vein) in combination with promedol or other analgesic and antispasmodic drugs to relieve angina attacks.
Papaverine hydrochloride is prescribed orally, under the skin, intramuscularly, intravenously and rectally.
Inside, adults take 0.04 - 0.08 g (40 - 80 mg) 3-4 times a day; children - also 3-4 times a day: from the age of 6 months to 2 years - 0.005 g (5 mg) per reception, 3-4 years - 0.005 - 0.01 g, 5-6 years - 0, 01 g, 7 - 9 years old - 0.01 - 0.015 g each, 10 - 14 years old - 0.015-0.02 g each.
If vomiting or difficulty swallowing is prescribed in the form of suppositories, 0.02-0.04 g 2-3 times a day (adults).
1 to 2 ml (usually 2 ml) of a 2% solution is injected under the skin and intramuscularly into adults, and intravenously - in the same dose (very slowly!), Diluting a 2% solution of papaverine hydrochloride in 10 - 20 ml of isotonic sodium chloride solution. Children are given in smaller doses according to age.
Higher doses for adults inside: single 0.2 g daily 0.6 g; under the skin, intramuscularly and into a vein: single 0.1 g daily 0.3 g