An alkaloid (see ALKALOIDS) obtained from the bark of various species of cinchona trees growing in Peru and neighbouring parts of South America and the East Indies. Its best-known action is in checking the recurrence of attacks of MALARIA, as it destroys malarial parasites in the blood. In fevers it acts as an antipyretic (see ANTIPYRETICS). The drug is also sometimes used in the treatment of cramps. Among its side-effects are ringing in the ears, temporary impairment of vision, and rare disturbance of kidney function leading to renal failure.
Its best-known action is in checking the recurrence of attacks of MALARIA, as it destroys malarial parasites in the blood. In fevers it acts as an antipyretic (see ANTIPYRETICS). The drug is also sometimes used in the treatment of cramps. Among its side-effects are ringing in the ears, temporary impairment of vision, and sometimes disturbance of kidney function leading to renal failure.