Medical Editor: John P. Cunha, DO, FACOEP Last updated on RxList: 12/7/2022

Drug Summary

What Is Papaverine?

Papaverine Hydrochloride Sustained Release Capsules is a vasodilator drug that relaxes veins and arteries, which makes them wider and allows blood to pass through them more easily and is used for the relief of cerebral and peripheral ischemia associated with arterial spasm and myocardial ischemia complicated by arrhythmias.

What Are Side Effects of Papaverine?

Papaverine may cause serious side effects including:

  • hives,
  • difficulty breathing,
  • swelling of your face, lips, tongue, or throat,
  • upper stomach pain,
  • loss of appetite,
  • dark urine,
  • clay-colored stools,
  • yellowing of the skin or eyes (jaundice),
  • skin rash,
  • bruising,
  • severe tingling,
  • numbness,
  • pain,
  • muscle weakness,
  • severe headache,
  • blurred vision,
  • fast heart rate,
  • pounding in your neck or ears,
  • anxiety,
  • shortness of breath,
  • extreme drowsiness,
  • vision changes, and
  • pain, swelling, or redness where the medicine was injected

Get medical help right away, if you have any of the symptoms listed above.

Side effects of Papaverine include:

  • nausea,
  • stomach discomfort,
  • loss of appetite,
  • dizziness,
  • drowsiness,
  • tiredness,
  • headache,
  • skin rash,
  • decreased appetite,
  • diarrhea,
  • constipation,
  • increased sweating,
  • facial flushing (warmth, redness, or tingly feeling),
  • general discomfort or feeling of being unwell (malaise),
  • spinning sensation (vertigo),
  • increased heart rate,
  • slight increase in blood pressure, and
  • irregular heartbeats.

Seek medical care or call 911 at once if you have the following serious side effects:

  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheartedness, or passing out;
  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

Dosage for Papaverine

Papaverine hydrochloride is administered intravenously (IV) 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.

What Drugs, Substances, or Supplements Interact with Papaverine?

Papaverine hydrochloride injection may interact with levodopa (Larodopa, Atamet, Parcopa, Sinemet). Other drugs may interact with papaverine injection. Tell your doctor all prescription and over-the-counter medications and supplements you use.

Papaverine During Pregnancy or Breastfeeding

During pregnancy, Papaverine should be used only if prescribed. It may be harmful to a fetus. It is unknown if this drug passes into breast milk or if it could harm a nursing baby. Consult your doctor before breastfeeding.

Additional Information

Our Papaverine hydrochloride injection Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

Drug Description


Papaverine hydrochloride, C20H21NO4•HCl, is a white, crystalline powder, odorless, with a slight bitter taste and is soluble in water.

Each capsule contains: papaverine hydrochloride USP 150 mg.

Chemically, it is Isoquinoline,1-[(3,4-dimethoxyphenyl)methyl]-6,7-dimethoxy-, hydrochloride. It has a molecular weight of 375.85. It has the following structural formula:

Papaverine Hydrochloride Structural Formula Illustration

Manufactured in a special base which is designed for prolonged release. Each capsule also contains the following inactive ingredients: FD&C blue No. 1, FD&C red No. 40, gelatin, pharmaceutical glaze, povidone, silicon dioxide, sodium lauryl sulfate, corn starch, sucrose and talc.

Indications & Dosage


For the relief of cerebral and peripheral ischemia associated with arterial spasm and myocardial ischemia complicated by arrhythmias.


One capsule every 12 hours. In difficult cases administration may be increased to one capsule every 8 hours or two capsules every 12 hours.


Papaverine Hydrochloride Sustained Release Capsules are supplied as: 150 mg brown and clear capsules, imprinted E 5156 and are available in bottles of 100, 500 and 1000.


Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].

Protect from moisture.

To report SUSPECTED ADVERSE REACTIONS, contact Sandoz Inc. at 1-800-525-8747 or FDA at 1-800-FDA-1088 or

Manufactured for: Sandoz Inc. Princeton, NJ 08540. Manufactured by: Epic Pharma, LLC. Laurelton, NY 11413. Rev. 11/08.

Side Effects & Drug Interactions


Although occurring rarely, the reported side effects of papaverine include nausea, abdominal distress, anorexia, constipation, malaise, drowsiness, vertigo, sweating, headache, diarrhea, skin rash, flushing of face, increase in heart rate and depth of respiration and slight increase in blood pressure.


No information provided.

Warnings & Precautions


No information provided.


Use with caution in patients with glaucoma. Hepatic hypersensitivity has been reported with gastrointestinal symptoms, jaundice, eosinophilia and altered liver function tests. Discontinue drug if these occur.

Overdose & Contraindications


No information provided.


Large doses can depress atrioventricular and intraventricular conduction and thereby produce serious arrhythmias.

Clinical Pharmacology


The main actions of papaverine are exerted on cardiac and smooth muscle. Like quinidine, papaverine acts directly on the heart muscle to depress conduction and prolong the refractory period. Papaverine relaxes various smooth muscles. This relaxation may be prominent if spasm exists. The muscle cell is not paralyzed by papaverine and still responds to drugs and other stimuli causing contraction. The antispasmodic effect is a direct one and unrelated to muscle innervation. Papaverine is practically devoid of effects on the central nervous system.

Papaverine relaxes the smooth musculature of the large blood vessels, especially coronary, systemic peripheral and pulmonary arteries. 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.

The direct actions of papaverine on the heart to depress conduction and irritability and to prolong the refractory period of the myocardium provide the basis for its clinical trial in abrogating atrial and ventricular premature systoles and ominous ventricular arrhythmias. The coronary vasodilator action could be an additional factor of therapeutic value when such rhythms are secondary to insufficiency or occlusion of the coronary arteries.

In patients with acute coronary thrombosis, the occurrence of ventricular cardiac arrhythmias is serious and requires measures designed to decrease myocardial irritability. Papaverine may have advantages over quinidine used for a similar purpose, in that it may be given in an emergency by the intravenous route, does not depress myocardial contraction or cause cinchonism and produces coronary vasodilation.

Medication Guide


No information provided. Please refer to the PRECAUTIONS sections.

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