Chloroquine: Price, Dosage & Where to Buy

Chloroquine is an antimalarial medicine used mainly to treat uncomplicated malaria caused by parasites that are sensitive to it. It can also prevent malaria in areas where chloroquine resistance is absent, but it is not suitable for every destination or type of malaria. Chloroquine requires a prescription in the United Kingdom, and generic versions are available.

Chloroquine acts on malaria parasites while they are inside red blood cells. These parasites break down haemoglobin, the substance that carries oxygen in blood, and this process releases material that is harmful to them. Chloroquine interferes with the parasites' ability to make that material harmless, allowing it to build up and damage them.

This action helps explain why chloroquine works against susceptible blood-stage parasites but does not clear the dormant liver stages responsible for relapses in some types of malaria. Resistant parasites can survive despite treatment.

Chloroquine treats uncomplicated malaria caused by susceptible strains of Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale and Plasmodium vivax. It is also used to prevent malaria in geographical areas where resistance to chloroquine is not present. Resistance is widespread in P. falciparum and has also been reported in P. vivax, so its suitability depends on the parasites present in the area concerned.

Chloroquine is not intended for complicated malaria, including malaria involving the brain or acute kidney failure. It does not act against dormant liver-stage parasites in P. vivax or P. ovale infections, so additional treatment is needed to prevent relapses. Another listed use is extraintestinal amoebiasis, an infection caused by amoebae outside the intestine.

The label lists oral tablets containing 250 mg or 500 mg, and coated oral tablets containing 500 mg. The label lists 250 mg chloroquine phosphate as equivalent to 150 mg chloroquine base. Dose descriptions distinguish between phosphate salt and base, which are not interchangeable amounts.

The label lists adult malaria prevention as 500 mg (= 300 mg base) once per week, on the same day each week. The label lists prevention beginning two weeks before exposure where possible and continuing for eight weeks after leaving the affected area. The label lists adult uncomplicated malaria treatment as an initial 1 g salt (= 600 mg base), followed by 500 mg (= 300 mg base) after six to eight hours and 500 mg (= 300 mg base) on each of two consecutive days.

Children's regimens are calculated by body weight and must not exceed the adult dose. The label lists adult extraintestinal amoebiasis treatment as 1 g salt (600 mg base) daily for two days, followed by 500 mg (300 mg base) daily for at least two to three weeks.

Store at 20-25°C in a tight, light-resistant container. Protect the tablets from light and moisture to maintain quality. Keep the medicine out of the sight and reach of children.

A missed dose may interrupt the planned malaria prevention or treatment schedule. General pharmacy advice is not to double a dose to make up for a missed one. Ask a pharmacist or prescriber how to resume the schedule, particularly during treatment for an active infection or if the timing is uncertain.

The label does not specify pregnancy or breastfeeding data. Anyone who is pregnant, planning a pregnancy or breastfeeding should discuss chloroquine with a doctor or pharmacist so that its suitability can be considered before treatment.