Papaverine
Papaverine is a vasodilator that relaxes smooth muscles in your blood vessels to help them dilate (widen). This lowers blood pressure and allows blood to flow more easily through your veins and arteries. Papaverine is used to treat many conditions that cause spasm of smooth muscle. This includes chest pain, circulation problems, heart attack, or disorders of the stomach or gallbladder. Papaverine is not for use in treating erectile dysfunction (impotence) and should not be injected into the penis. This practice has resulted in painful or prolonged erection that may require surgery to correct.
Mechanism of effect
Perhaps by its direct vasodilating action on cerebral blood vessels, Papaverine increases cerebral blood flow and decreases cerebral vascular resistance in normal subjects; oxygen consumption is unaltered. These effects may explain the benefit reported from the drug in cerebral vascular encephalopathy.
Pharmacodynamic
The most characteristic effect of papaverine is relaxation of the tonus of all smooth muscle, especially when it has been spasmodically contracted. Papaverine Hydrochloride apparently acts directly on the muscle itself. This relaxation is noted in the vascular system and bronchial musculature and in thegastrointestinal, biliary and urinary tracts.
Pharmacokinetics
Papaverine is effective by all routes of administration. A considerable fraction of the drug localizes in fat deposits and in the liver, with the remainder being distributed throughout the body. It is metabolized in the liver. About 90% of the drug is bound to plasma protein. Although estimates of its biologic half-life vary widely, reasonably constant plasma levels can be maintained with oral administration at 6 hour intervals. The drug is excreted in the urine in an inactive form.
Drug indications
vasospasmsDosage
Parenteral administration of papaverine hydrochloride in doses of 1 to 4 mL is repeated every 3 hours as indicated. In the treatment of cardiac extrasystoles, 2 doses may be given 10 minutes apart.
Drug contraindications
complete atrioventricular heart block
Side effects
nausea , Headache , constipation , Tachycardia , abdominal pain , rash , flushing , vertigo , Diarrhea , Hypertension , anorexia , malaise , hepatitis , general discomfort , excessive sedation , cirrhosis
Interactions
Duloxetine , Levodopa/carbidopa , Nicorandil , Valsartan , Sevoflurane , Pentamidine , Sodium Oxybate , Histrelin , Dolasetron , Palonosetron , vandetanib , Dofetilide , Goserelin , Anagrelide , Vasopressin , Halofantrine , Grepafloxacin , Terfenadine , Abarelix , Asenapine , Alfuzosin , Perflutren , Apalutamide , Pitolisant , gilteritinib , glasdegib , Bepridil , bedaquiline , Dasatinib , NesiritideAlerts
1-This product is to be used by or under the direction of a physician. 2-Papaverine Hydrochloride is not indicated for the treatment of impotence by intracorporeal injection. The intracorporeal injection of papaverine hydrochloride has been reported to have resulted in persistent priapism requiring medical and surgical intervention. 3-Papaverine Hydrochloride should be used with caution in patients with glaucoma.
Points of recommendation
The medication should be discontinued if hepatic hypersensitivity with gastrointestinal symptoms, jaundice, or eosinophilia becomes evident or if liver function test values become altered.
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