Quinine

Scientific Name(S): Cinchona succirubra Pav. ex Klotsch (red cinchona), C. calisya Wedd. and C. ledgeriana Moens ex Trim. (yellow cinchona). Family: Rubiaceae

Common Name(S): Red bark, Peruvian bark, Jesuit's bark, China bark, cinchona bark, quina-quina, fever tree

Botany: The cinchonas are evergreen shrubs and trees that grow to heights of 50 to 100 feet. They are native to the mountainous areas of tropical Central and South America, including regions of Bolivia, Costa Rica and Peru. The oblong seed capsule is about 3 cm long and, when ripe, splits open at the base. Each capsule contains from 40 to 50 slender seeds that are so light that approximately 75,000 seeds equal one ounce. In addition, these trees are found in Africa, South America and Southeast Asia. At least one other genus (Remijia) of the same family has been reported to contain quinidine.

History: The dried ground bark of the cinchona plant has been used for centuries for the treatment of malaria, fever, indigestion, mouth and throat diseases, and cancer. The name cinchona is said to be derived from the Countess of Chinchon, the wife of a viceroy of Peru, who it was long believed was cured in 1638 from a fever by the use of the bark; however, the story has been widely disputed. Formal use of the bark to treat malaria was established in the mid-1800s when the British began the worldwide cultivation of the plant in order to assure the continuing availability, which was in danger of extinction in some regions due to overcultivation.

Extracts of the bark have been used to treat hemorrhoids, to stimulate hair growth and to manage varicose veins. Quinine has been used as an abortifacient. Extracts of cinchona have a bitter, astringent taste and have been used as flavoring for foods and beverages. Although the use of quinine for the treatment of malaria has been largely supplanted by treatment with semisynthetic antiinfectives, its use persists in some regions of the world.

Uses of Quinine:

Quinine has been used for the treatment of leg cramps caused by vascular spasm, internal hemorrhoids, varicose veins and pleural cavities after thoracoplasty, malaria, and associated febrile states.

Side Effects of Quinine:

Quinine has been known to cause urticaria, contact dermatitis, and other hypersensitivity reactions.

Toxicology: Ground cinchona bark and quinine have been reported to cause urticaria, contact dermatitis and other hypersensitivity reactions in humans. These reactions also may occur in persons using topical preparations containing cinchona extracts or quinine. The ingestion of these alkaloids can result in the clinical syndrome known as "cinchonism." Persons who are hypersensitive to these alkaloids also may develop the syndrome, which is characterized by severe headache, abdominal pain, convulsions, visual disturbances and blindness, auditory disturbances such as ringing in the ears, paralysis and collapse.

Therapeutic doses of quinine have resulted in acute hemolytic anemia, a limitation for it§ use in a small but significant portion of the population who are glucose-6­phosphate dehydrogenase (G-6-PD) deficient.

Quinidine and related alkaloids are rapidly absorbed from the gastrointestinal tract, and a single 2 to 8 g oral dose of quinine may be fatal to an adult.

Quinine use is discouraged during pregnancy due to fetal and abortifacient effects. Treatment of overdose is generally supportive. Urinary acidification and renal dialysis can be employed if necessary.

Summary: Quinine and its related alkaloids have been used for more than 100 years for the treatment of malaria and associated febrile states. Other alkaloids possess antiarrhythmic activity. Chronic ingestion may lead to cinchonism, and hypersensitivity reactions have been observed.