While it is found in the opium poppy, papaverine differs in both structure and pharmacological action from the analgesic morphine and its derivatives (such as codeine).

[6][7] Papaverine, when injected in penile tissue, causes direct smooth muscle relaxation and consequent filling of the corpus cavernosum with blood resulting in erection.

[22] Frequent side effects of papaverine treatment include polymorphic ventricular tachycardia, constipation, interference with sulphobromophthalein[citation needed] retention test (used to determine hepatic function), increased transaminase levels, increased alkaline phosphatase levels, somnolence, and vertigo.

Rare side effects include flushing of the face, hyperhidrosis (excessive sweating), cutaneous eruption, arterial hypotension, tachycardia, loss of appetite, jaundice, eosinophilia, thrombopenia, mixed hepatitis, headache, allergic reaction, chronic active hepatitis, and paradoxical aggravation of cerebral vasospasm.

The codecarboxylate is sold under the name Albatran,[citation needed] the adenylate as Dicertan,[citation needed] and the hydrochloride salt is sold variously as Artegodan (Germany), Cardioverina (countries outside Europe and the United States), Dispamil (countries outside Europe and the United States), Opdensit (Germany), Panergon (Germany), Paverina Houde (Italy, Belgium), Pavacap (United States), Pavadyl (United States), Papaverine (Israel), Papaverin-Hamelin (Germany), Paveron (Germany), Spasmo-Nit (Germany), Cardiospan, Papaversan, Cepaverin, Cerespan, Drapavel, Forpaven, Papalease, Pavatest, Paverolan, Therapav (Canada[25]), Vasospan, Cerebid, Delapav, Dilaves, Durapav, Dynovas, Optenyl, Pameion, Papacon, Pavabid, Pavacen, Pavakey, Pavased, Pavnell, Alapav, Myobid, Vasal, Pamelon, Pavadel, Pavagen, Ro-Papav, Vaso-Pav, Papanerin-hcl, Qua bid, Papital T.R., Paptial T.R., Pap-Kaps-150.

[citation needed] In Hungary, papaverine and homatropine methylbromide are used in mild drugs that help "flush" the bile.