Cinchonism

The cardiovascular adverse effects associated with quinidine therapy are hypotension and tachycardia, both of which are related to its a-adrenoceptor blocking actions. The tachycardia may be a reflex adjustment to the fall in blood pressure or may also be a direct action of the dmg on sympathetic nerve terminals leading to an increased release of NE. Quinidine also produces ringing in the ears (cinchonism) (1,2). 

It will be seen from the foregoing that there is no systematic nomenclature for these compounds. Some of them have been isolated by several workers and with the impression that they were new substances have been given new names, and this applies especially to the two isocinchonines and dihydrocinchonine. It will be noticed that instead of the two geometrical isomerides required by formula (Ga) there are three cinchon-hydrines. The a- and jS-forms are well-defined crystalline substances, but the supposed y-form (see table, p. 452) is amorphous and its authenticity doubtful. Eormula (E) requires two geometrical isomerides, but quinidine... 

The use of quinine can cause cinchonism at full therapeutic doses. Cinchonism is a group of symptoms associated with quinine, including tinnitus, dizziness, headache, gastrointestinal disturbances, and visual disturbances. These symptoms usually disappear when the dosage is reduced. Other adverse reactions include hematologic changes, vertigo, and skin rash. 

Quinidine Cinchonism, diarrhea, abdominal cramps, nausea, vomiting, hypotension, TdP, aggravation of underlying HF, conduction disturbances or ventricular arrhythmias, fever, hepatitis, thrombocytopenia, hemolytic anemia... 

Barrocas AM, Cymet T. (2007) Cinchonism in a patient taking quinine for... 

The scope of Michael additions with catalysts containing cyclohexane-diamine scaffolds was broadened by Li and co-workers [95]. When screening for a catalyst for the addition of phenylthiol to a,p-nnsatnrated imides, the anthors fonnd that thiourea catalyst 170 provided optimal enantioselectivities when compared to Cinchon alkaloids derivatives (Scheme 41). Electrophile scope inclnded both cyclic and acyclic substrates. Li attributed the enantioselectivity to activation of the diketone electrophiles via hydrogen-bonding to the thiourea, with simultaneous deprotonation of the thiol by the tertiary amine moiety of the diamine (170a and 170b). Based on the observed selectivity, the anthors hypothesized that the snbstrate-catalyst... 

Cinchonism characterized by giddiness, headache, tinnitus with hearing deficits, nausea, diarrhoea and blurring of vision becomes manifest if serum levels exceed 10 pg/ml. Rapid intravenous administration may cause cardiotoxicity with hypotension and arrhythmias. 

Large doses of quinidine can produce a syndrome known as cinchonism, which is characterized by ringing in the ears, headache, nausea, visual disturbances or blurred vision, disturbed auditory acuity, and vertigo. Larger doses can produce confusion, delirium, hallucinations, or psychoses. Quinidine can decrease blood glucose concentrations, possibly by inducing insulin secretion. 

L E. Quinidine. These are the classic signs of cinchon-ism and are adverse effects of quinidine and quinine, constituents of the cinchona tree. Some of these effects could be seen as toxic effects of phenytoin. However, auditory acuity is associated with cinchonism and not with phenytoin toxicity. Nausea but not the other effects could be associated with ciprofloxacin. Excessive drowsiness would be expected if diazepam were involved. These effects would not be expected with the estrogen replacement therapy. 

Mild cinchonism (ringing in ears, blurred vision, hearing loss) or severe cinchonism (headache, verfigo, diaphoresis, lighf-headedness, photophobia, confusion, delirium)... 

Nausea, headache, tinnitus, slight visual disturbances (mild cinchonism) Occasional... 

Overdosage (severe cinchonism) may result in cardiovascular effects, severe headache, intestinal cramps w/vomiting and diarrhea, apprehension, confusion, seizures, blindness, and respirafory depression. 

Assess level of hearing, visual acuity, presence of headache/tinnitus, nausea and report adverse effects promptly (possible cinchonism)... 

Adverse effects include SA block or arrest, high grade AV block, ventricular tachycardia, arrhythmia or ventricular asystole, polymorphic ventricular tachyarrhythmia, hypotension (particularly when given IV), cinchonism, tinnitus, loss of hearing, gastrointestinal upset, severe headache, diplopia, photophobia, etc. 

Adverse effects include nausea, vomiting, epigastric discomfort, skin rash, itching, hypotension, haemolysis, blurred vision, vertigo, tinnitus and cinchonism. 

Despite being a wonder drug against malaria, quinine in therapeutic doses can cause various side-effects, e.g. nausea, vomiting and cinchonism, and in some patients pulmonary oedema. It may also cause paralysis if accidentally injected into a nerve. An overdose of quinine may have fatal consequences. Non-medicinal uses of quinine include its uses as a flavouring agent in tonic water and bitter lemon. 

Gastrointestinal adverse effects of diarrhea, nausea, and vomiting are observed in one third to one half of patients. A syndrome of headache, dizziness, and tinnitus (cinchonism) is observed at toxic drug concentrations. Idiosyncratic or immunologic reactions, including thrombocytopenia, hepatitis, angioneurotic edema, and fever, are observed rarely. 

Antiarrhythmic therapy carries with it a number of risks. In some cases, the risk of an adverse reaction is clearly related to high dosages or plasma concentrations. Examples include lidocaine-induced tremor or quinidine-induced cinchonism. In other cases, adverse reactions are unrelated to high plasma concentrations (eg, procainamide-induced agranulocytosis). For many serious adverse reactions to antiarrhythmic drugs, the combination of drug therapy and the underlying heart disease appears important. 

Quinidine Similar to procainamide but more toxic (cinchonism, torsade) rarely used ... 

Quinine is a naturally occurring alkaloid obtained from Cinchona bark, with a mechanism of action similar to that of chloroquine. Quinine is very useful in treating chloroquine-resistant Plasmodium falciparum. In toxic doses, it may cause cinchonism characterized by tinnitus, headache, nausea, and visual disturbances. 

Quinine is a cinchona alkaloid that acts rapidly against all four species of Plasmodium. It is used to treat protozoal infections and leg cramps, and as a bitter and flavoring agent. However, the drug is not used prophylactically for malaria. Quinines are contraindicated in patients with a history of hypersensitivity to quinine or quinidine. They should not be used in the presence of hemolysis and should be used with caution in patients with atrial fibrillation, cardiac conduction defects, or heart block. Quinine administration in myasthenia gravis may aggravate the disease, hence it should be avoided. Quinine can be used in pregnancy.37 Intravenous infusion of quinine should be slow, and the patient should be monitored for cardiotoxicity.38 Cinchonism, which is characterized by tinnitus, GI disturbances, and impaired vision may occur with therapeutic doses of quinine.39... 

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