Drotaverine decreases active ionized calcium supply binding to smooth muscle cells due to inhibition of phosphodiesterase and intracellular accumulation of cAMP. It has an apparent and prolonged action on smooth muscles of internal organs and blood vessels and it moderately decreases arterial blood pressure, increases cardiac output (minute volume of heart), and has some antiarrhythmic potential.[5]
Possible side effects include: heating sensation, dizziness, headache (rarely), insomnia. May be observed: arrhythmia (rarely), hypotension, tachycardia, sweating, nausea.[5]
In Israel the product is known under the brand name "No-Spa" by the general public[14] which did not receive a permit to be distributed by the health ministry,[15] however due to high demand local medical counterfeiters have managed to smuggle No-Spa tablets over the years.[15]
In 2008, the Israeli health organization warned consumers against counterfeit No-Spa pills after a smuggler had been arrested at the Ben Gurion Airport with several thousand pills.[16][17]
In 2011, the Israeli patent and trademark office declined the use of No-SPA.[14]
Risks
An article from 2013 described the effects from overdose (in a 19-year-old female) as including vomiting, seizures and fatal cardiac toxicity.[18]
In 2016, the young Russian chess player Ivan Bukavshin died of a massive overdose (or poisoning) of the drug, which was initially thought to be a stroke; the dose detected in his blood was 17 mg/kg.[19]
^Padubidri V, Anand E (2006). Title Textbook of Obstetrics. BI Publications Pvt Ltd. p. 283. ISBN9788172252236.
^Singh KC, Jain P, Goel N, Saxena A (January 2004). "Drotaverine hydrochloride for augmentation of labor". International Journal of Gynaecology and Obstetrics. 84 (1): 17–22. doi:10.1016/s0020-7292(03)00276-5. PMID14698825. S2CID43824027.