What does quinidine mean?
Quinidine is an alkaloid derived from the bark of the cinchona tree and a member of the class of drugs known as class I antiarrhythmics. It is used to treat or convert certain abnormal heart rhythms, particularly some forms of atrial fibrillation or flutter. Historically, quinidine was also important in the treatment of malaria, before more effective and generally safer antimalarial medicines became available. Its clinical use is now limited because it can cause serious adverse effects, including unexpected changes in heart rhythm, low blood pressure, and syncope. Quinine is a chemically related cinchona alkaloid, but the medicines are not interchangeable: quinine is now used chiefly for nocturnal leg cramps, while quinidine has a distinct role in cardiac treatment. The word is most often encountered in medical contexts, particularly when describing quinidine toxicity or an adverse reaction to treatment.
nounAn alkaloid obtained from cinchona bark and used in the form of its salts as an antiarrhythmic medicine to treat certain abnormal heart rhythms. It has also been used as an antimalarial drug.
- A cinchona-derived alkaloid used as an antiarrhythmic drug to treat or convert certain abnormal cardiac rhythms.
- A bitter alkaloid related to quinine that has also been used in the treatment of malaria.
"The physician prescribed quinidine after an ECG confirmed an irregular atrial rhythm."
"Quinidine may be used to restore a normal heart rhythm when other treatments are unsuitable."
"Before the discovery of more modern antiarrhythmic medicines, quinidine was widely prescribed for malaria and other febrile illnesses."
The plural is uncommon and generally denotes different quinidine substances or preparations.
"The researchers compared the effects of several quinidines on cardiac tissue."
Quinidine is a close chemical relative of quinine, but the two medicines have very different modern uses: one is chiefly an antiarrhythmic, while the other is best known for treating night-time leg cramps.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does quinidine come from?
Quinidine is named within the family of alkaloids obtained from cinchona bark, which also gave English the name quinine. The element -idine is a chemical suffix used in names adopted for cinchona alkaloids. The words quinology, quinologist, and quinism likewise belong to the same etymological family, ultimately associated with the Quechua word for cinchona bark through Spanish.
How quinidine is actually used
Quinidine is a prescription medicine associated with potentially serious adverse effects, including cardiac arrhythmias and low blood pressure. The name usually denotes the medicinal alkaloid or its pharmaceutical salts rather than a naturally occurring object.
Easily confused with quinidine
Quinidine is a distinct cinchona alkaloid and antiarrhythmic drug, whereas quinine is a related alkaloid now used chiefly for leg cramps and historically as an antimalarial.