The first chemical cure for an infection came from tree bark
Quinine, isolated from Peruvian cinchona in 1820, treated malaria long before germ theory matured. Bark extracts reached Spain by 1636 via Jesuit missionaries; use dates to at least 1632. It remains on the WHO Essential Medicines list—yet since 2006 is no longer first-line when safer options exist.
The alkaloid fights Plasmodium falciparum—including some chloroquine-resistant cases when artesunate is unavailable—and babesiosis. It may be swallowed or given intravenously. Common effects include headache, tinnitus, vision trouble, and sweating; severe risks include deafness, low platelets, and arrhythmia. Pregnancy harm is unclear, but treating malaria with quinine when appropriate is still advised. WHO now prefers artemisinins; quinine is reserved when those are missing. An FDA warning since 2010 has curbed off-label night-cramp prescriptions after life-threatening reactions. It also appears in lupus and arthritis care and can inhibit monoamine oxidase.
Adolph Strecker fixed the molecular formula in 1854; the family is called cinchona alkaloids. Salts—hydrochloride, sulfate, gluconate, and others—travel orally or by IV; gluconate can go intramuscular or rectal. U.S. Qualaquin tablets hold 324 mg sulfate; no injectable quinine is licensed there, so quinidine substitutes. Bars mark tonic with “Q.” Colonial drinkers mixed bitter tonic with gin; today’s soft-drink limits are 83 ppm in the United States, 85 mg/L in Taiwan, 100 mg/L in the European Union—enough for flavor, not reliable prophylaxis.
The leading action model, borrowed from chloroquine, blocks hemozoin formation so toxic free heme kills the parasite; nucleic-acid and protein synthesis and glycolysis may also suffer. Cinchonism clusters headache, sweating, nausea, tinnitus, and color-vision shifts; oral bitterness often triggers vomiting. Narrow therapeutic windows make quinine a frequent cause of drug-induced injury—even beverage traces can strike multiple organs—so it is history’s pioneering anti-infective chemical and a reminder that dose is destiny.
Source: Quinine
