Sustained-release products may be poorly and erratically absorbed. Metabolized in the liver and inactive metabolites excreted in the urine. Complete AV block. Use with extreme caution in coronary insufficiency and glaucoma. Flushing of face, hypertension, increase in HR and depth of respiration.
Large doses can depress AV and intraventricular conduction, causing serious arrhythmias.
Headache, drowsiness, sedation, vertigo. Both acute and chronic poisoning may result from use of papaverine. Symptoms are extensions of side effects. Delay absorption by giving tap water, milk, or activated charcoal followed by gastric lavage or induction of vomiting and then a cathartic. Maintin BP and take measures to treat respiratory depression and coma.