Quinine - Adverse Effects

Adverse Effects

Quinine can, in therapeutic doses, cause cinchonism; in rare cases, it may even cause death (usually by pulmonary edema). The development of mild cinchonism is not a reason for stopping or interrupting quinine therapy, and the patient should be reassured. Blood glucose levels and electrolyte concentrations must be monitored when quinine is given by injection. The patient should ideally be in cardiac monitoring when the first quinine injection is given (these precautions are often unavailable in developing countries where malaria is endemic).

Cinchonism is much less common when quinine is given by mouth, but oral quinine is not well tolerated (quinine is exceedingly bitter and many patients will vomit after ingesting quinine tablets): Other drugs such as Fansidar (sulfadoxine with pyrimethamine) or Malarone (proguanil with atovaquone) are often used when oral therapy is required. Quinine ethyl carbonate is tasteless and odourless, but is available commercially only in Japan. Blood glucose, electrolyte and cardiac monitoring are not necessary when quinine is given by mouth.

Quinine can cause paralysis if accidentally injected into a nerve. It is extremely toxic in overdose, and the advice of a poisons specialist should be sought immediately.

Quinine in some cases can lead to constipation, erectile dysfunction, or diarrhea.

The New York Times Magazine described a case, presenting with fever, hypotension, and blood abnormalities mimicking septic shock.