Quinine - Dosing and Indication

Dosing and Indication

As of 2006, quinine is no longer recommended by the WHO as first-line treatment for malaria, and should be used only when artemisinins are not available.

Quinine is a basic amine and is always presented as a salt. Various existing preparations include the hydrochloride, dihydrochloride, sulfate, bisulfate and gluconate. This makes quinine dosing complicated, since each of the salts has a different weight.

The following amounts of each salt form contain equal amounts of quinine:

• quinine base 100 mg
• quinine bisulfate 169 mg
• quinine dihydrochloride 122 mg
• quinine hydrochloride 111 mg
• quinine sulfate (actually (quinine)₂H₂SO₄∙2H₂O) 121 mg
• quinine gluconate 160 mg

All quinine salts may be given orally or intravenously (IV); quinine gluconate may also be given intramuscularly (IM) or rectally (PR). The main problem with the rectal route is the dose can be expelled before it is completely absorbed; in practice, this is corrected by giving a half dose again.

The IV dose of quinine is 8 mg/kg of quinine base every eight hours; the IM dose is 12.8 mg/kg of quinine base twice daily; the PR dose is 20 mg/kg of quinine base twice daily. Treatment should be given for seven days. For at least the IV formulation, a loading dose of 20 mg/kg is required.

The preparations available in the UK are quinine sulfate (200-mg or 300-mg tablets) and quinine hydrochloride (300 mg/ml for injection). Quinine is not licensed for IM or PR use in the United Kingdom. The adult dose in the UK is 600 mg quinine dihydrochloride IV or 600 mg quinine sulfate orally every eight hours. For nocturnal leg cramps, the dosage is 200–300 mg at night.

In the United States, quinine sulfate is commercially available in 324-mg tablets under the brand name Qualaquin; the adult dose is two tablets every eight hours. No injectable preparation of quinine is licensed in the US; quinidine is used instead.