Cinchonism is an adverse reaction to the antiprotozoal drug quinine, manifested by headaches, auditory and visual deficits, as well as tinnitus. The diagnosis is made by confirming recent use of this agent during patient history. Treatment depends on the severity of symptoms and may necessitate hemodialysis in severe cases.
Various side-effects of quinine use exist, but cinchonism includes nausea, vomiting and tinnitus as constitutive features . Flushing, marked visual and auditory abnormalities, as well as abdominal pain and hypersensitivity reactions (ranging from urticaria to bronchospasm and anaphylactic shock) may be encountered .
If patient history reveals history of quinine use, the diagnosis should be made immediately, whereas electrocardiography (ECG) and determination or renal function through measurement of blood urea nitrogen (BUN) and creatinine is recommended to assess the state of the cardiovascular system.
Treatment of cinchonism is mainly in the form of dose reduction or cessation of quinine use, but patients in whom other manifestations of quinine toxicity (for ex. severe central nervous system and renal impairment) can be severe or even life-threatening , hemodialysis may be option, with a goal of prompt removing of the drug from circulation .
Depending on the dose ingested and severity of symptoms, the prognosis may range from self-limiting complaints to life-threatening organ failure . For this reason, a prompt diagnosis is vital to ensure a quick recovery and to prevent further complications.
The exact rates of cinchonism remain unknown. A significant risk factor for this condition, however, is seen in patients with long QT syndrome, renal disease, myasthenia gravis, optic neuritis and G6PD, suggesting that this drug should be contraindicated in these patients .
The exact mechanism of action of quinine is yet to be determined and which mechanisms lead to the development of cinchonism remains unknown .
Proper patient monitoring and dose tapering can significantly reduce the risk of cinchonism .
Cinchonism is a clinical syndrome associated with ingestion of quinine, an antiprotozoal drug that exerts various effects in the body . Quinine is derived from the bark of the cinchona tree that grows in the Andes, South America and its synthetic production started during the 20th century to combat malarial disease . Although the mechanism of action of quinine still remains incompletely understood, analgesic, antipyretic and antiinflammatory properties have been described . This drug (and its stereoisomer quinidine) is very efficient against Plasmodium vivax and ovale species, but not Plasmodium falciparum and it is one of the main drugs against babesiosis . Unfortunately, various side-effects have been observed at regular dosages, one of them being cinchonism, which is characterized by tinnitus, headaches, both auditory and visual deficits and anaphylactic shock in rare cases . The diagnosis is relatively easy to make, whereas treatment may include discontinuation of the drug, dose tapering or hemodialysis . To reduce the risk of cinchonism, quinine should be avoided in patients suffering from cardiac (most importantly long QT syndrome) or renal disease, myasthenia gravis, optic neuritis or glucose-6-phosphate deficiency (G6PD)  , as a more severe reaction to the drug is observed under such circumstances.
Cinchonism is a medical term that is used to describe the appearance of specific symptoms as a result of quinine toxicity. Quinine is a drug derived from the bark of the cinchona tree that grows in the Andes in South America (hence the term cinchonism) and it is primarily used as an antiparasitic agent in treatment of malaria and babesiosis. Its exact mechanism of action remains unknown, but it can cause various adverse affects. Visual and auditory disturbances, tinnitus, headaches, nausea and vomiting are main features of cinchonism, whereas patients with a severe reaction to the drug can develop anaphylaxis (a profound, life-threatening allergic reaction to the drug). The diagnosis should be made as soon as the use of quinine is discovered during patient history taking and discontinuation of the drug (or dose reduction) is sufficient in the majority of cases. To reduce the risk of cinchonism, quinine should never be administered to patients suffering from renal disease, cardiac abnormalities such as long QT syndrome, myasthenia gravis, optic neuritis or glucose-6-phosphate deficiency (G6PD).