“…Two systematic reviews published within the last five years both concluded that quinine is modestly effective (reduces cramp frequency by about a quarter, cramp intensity by a tenth and number of days by a fifth). 3,4 Other pharmacologic measures were found to be either possibly effective (vitamin B complex, naftidrofuryl, calcium-channel blockers) or likely not effective (gabapentin, magnesium). 3 A variety of adverse effects can occur with the usual therapeutic doses of quinine, including cinchonism (marked by tinnitus, high-tone hearing loss, photophobia and other visual disturbances, dysphoria, headache, nausea, vomiting, sweating, dizziness and postural hypotension), hypoglycemia (from the drug's stimulatory effect on pancreatic β cells; most common in the treatment of severe malaria), hypotension (usually related to intravenous infusion of the drug), hearing and visual disturbances (including irreversible loss), gastrointestinal symptoms, cutaneous effects, conduction abnormalities (mild prolongation of the corrected QT interval, which is rare unless plasma levels are elevated), arrhythmias and hemolysis (from hypersensitivity or in patients with G6PD deficiency).…”