Papaverine hydrochloride

Papaverine hydrochloride is a medicine used for problems with the gastrointestinal tract. It belongs to the category of papaverines and its derivatives.

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Indications Papaverine hydrochloride

It is used in the following situations:

• elimination and prevention of smooth muscle spasms in the area of internal organs against the background of spastic colitis, as well as pylorospasm or cholecystitis;
• elimination of colic in the kidneys and stomach;
• treatment of impotence of vascular origin;
• therapy for obliterating endarteritis and spasms in the cerebral vessels, as well as the extremities (an integral part of combination treatment).

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Release form

The drug is released in the form of a 2% solution for injection, in 2 ml ampoules. There are 10 such ampoules inside the blister plate. The box contains 1 or 2 blisters with ampoules.

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Pharmacodynamics

The drug has antispasmodic and antihypertensive properties.

The action of papaverine is due to its blocking effect on the activity of the PDE4 component. Due to the blockade of the enzyme, the hydrolysis of the cAMP element is stopped, and its values in the cells of smooth muscle vessels and internal organs increase. The cAMP element reduces the volume of calcium ions entering the muscle cells, and in addition, it inactivates the kinase located in the light myosin chains (this is a contractile protein that promotes muscle contraction processes).

The medicine helps to relax the smooth muscles of the vessels and internal organs, and at the same time reduce their tone (respiratory and urogenital system, as well as the gastrointestinal tract). The active substance mainly dilates the arterial vessels and increases the volume of blood flow (this also includes cerebral).

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Pharmacokinetics

When administered intramuscularly and subcutaneously, the drug is completely and quickly absorbed. The medicinally effective values of the drug in plasma are 0.2-2 μg/ml. After repeated administration of the drug, its pharmacokinetic parameters remain the same.

Protein synthesis inside the plasma reaches 90%. The drug easily penetrates histohematic barriers. It forms a depot inside fatty tissues, as well as the liver (inside it, papaverine is biotransformed). The half-life of the drug is 0.5-2 hours.

Excretion occurs with urine, in the form of decay products. A small portion of the drug (less than 0.5%) is excreted unchanged.

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Dosing and administration

The solution is administered in several ways: intramuscularly, subcutaneously or intravenously.

For adults, the required dosage is 20-40 mg (equal to 1-2 ml of a 2% solution), which is administered 2-4 times a day (with a minimum interval of 4 hours between injections). If an intravenous injection of 10 mg of the drug (1 ml) is required, the solution must first be diluted with sodium chloride (10-20 ml of a 0.9% solution). No more than 0.2 g of the solution (10 ml) can be administered per injection, and a maximum of 0.3 g (15 ml) per day in total.

To eliminate impotence of vascular origin, it is necessary to administer an intracavernous injection - in the amount of 10 mg (0.5 ml). The procedure should be carried out 20-30 minutes before the expected sexual intercourse.

People aged 70 years and over can be administered a maximum of 10 mg of the drug at a time (0.5 ml).

For children aged 1-12 years, the solution is administered at a rate of 0.3-0.5 mg/kg 2-3 times/day.

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Use Papaverine hydrochloride during pregnancy

The solution is sometimes used in late pregnancy, shortly before delivery, to reduce uterine hypertonicity and reduce the risk of premature birth.

Contraindications

Among the contraindications:

• infants up to 12 months;
• state of coma or suppression of respiratory activity;
• glaucoma;
• AV block;
• the presence of intolerance to papaverine;
• people over 75 years of age (too high a risk of developing hyperthermia);
• Peyronie's disease (performing intracavernous injections).

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Side effects Papaverine hydrochloride

The use of the solution sometimes causes the following side effects:

• constipation or nausea;
• hyperhidrosis or feeling of drowsiness;
• development of eosinophilia and increased transaminase values;
• AV block, decreased blood pressure, ventricular extrasystole;
• Peyronie's disease or priapism caused by intracavernous injection.

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Overdose

Signs of poisoning occur after injection of a large dose of the solution, especially if the patient has kidney or liver disease. Typically, diplopia, a feeling of drowsiness or weakness, and decreased blood pressure develop.

The drug has no specific antidote. To eliminate the disorder, stop using the drug, perform gastric lavage, give the victim activated carbon and milk, and at the same time carry out symptomatic and supportive treatment procedures. This will help increase blood pressure and eliminate other disorders.

To get rid of priapism, which develops as a result of intracavernous injection of the solution, it is necessary to administer phenylephrine and adrenaline intracavernously. In severe forms of the disease, hemoaspiration is performed, as well as shunting in the area of the vessels of the penis.

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Interactions with other drugs

As a result of the combination with papaverine, the antihypertensive properties of methyldopa are reduced and the effects of alcohol are enhanced.

Smokers have an accelerated metabolism of the substance papaverine, so its plasma values, as well as medicinal properties, are weakened.

Phentolamine enhances the effectiveness of the drug in relation to the cavernous bodies of the penis in case of combined use.

Metamizole with diphenhydramine and diclofenac enhance the antispasmodic effect of papaverine.

Papaverine hydrochloride solutions are not medicinally compatible with glucose solution (due to partial inactivation of the action of papaverine).

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Storage conditions

Papaverine hydrochloride should be kept in a place out of reach of children and sunlight. Temperature indicators – maximum 25ºС.

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Shelf life

Papaverine hydrochloride is allowed to be used for 2 years from the date of release of the therapeutic agent.

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