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Antimalarial (quinoline); also historically used for muscle cramps

Quinine: uses, side effects & precautions

Also known as Qualaquin.

Esta información es solo orientativa de carácter general y no constituye un consejo médico. Consulta siempre a un profesional sanitario cualificado para cualquier asunto médico personal. En caso de emergencia, llama al número de emergencias de tu zona.

What it is used for

  • Treatment of malaria, including some severe or resistant cases, often combined with another medicine
  • Limited use for night-time leg cramps in specific situations under medical supervision

How it works

Quinine kills malaria parasites in red blood cells by interfering with their ability to break down and detoxify haemoglobin.

How it is taken

Taken as oral tablets, or given by injection in a hospital for severe malaria. For malaria it is taken as a course, often alongside an antibiotic. Take it exactly as your doctor or pharmacist directs, and complete the course.

No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.

Common side effects

  • Ringing in the ears
  • Temporary hearing changes
  • Headache
  • Nausea
  • Dizziness
  • Blurred vision
  • Flushing

Serious effects — get help

  • A cluster of symptoms called cinchonism (severe ringing in the ears, deafness, blurred vision, confusion) — contact your clinician
  • Sudden drop in blood platelets causing unusual bruising or bleeding — seek urgent care
  • Severe low blood sugar (sweating, confusion, faintness) — seek urgent care
  • Irregular heartbeat or fainting — seek urgent care
  • Severe allergic or skin reaction — seek emergency care
  • Anemia in people with G6PD deficiency — urgent care

If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.

Interactions to watch

  • Other medicines that affect heart rhythm
  • Blood thinners such as warfarin (effect may increase)
  • Antacids (can reduce absorption)
  • Some heart and stomach medicines
  • Other antimalarials

Who should take care

  • Tell your clinician about heart-rhythm problems, ringing in the ears, or hearing loss
  • Mention G6PD deficiency, low platelets, or previous reactions to quinine
  • Report kidney or liver problems
  • Inform your clinician if pregnant or breastfeeding
  • Avoid tonic water as an unmonitored source and discuss all sources of quinine

Frequently asked questions

Why does quinine make my ears ring?
Ringing in the ears and temporary hearing changes are common with quinine and usually ease after the course. Tell your clinician if it is severe or you become confused or notably deaf.
Can I take it for leg cramps?
Its use for leg cramps is limited and only under medical supervision because of safety risks. Do not self-treat cramps with it — ask your clinician.
Why is it sometimes given with an antibiotic?
Pairing quinine with an antibiotic such as a tetracycline or clindamycin can improve cure rates for malaria. Take both exactly as directed.
What bleeding signs should worry me?
Unusual bruising, tiny red spots on the skin, nosebleeds, or bleeding gums can signal a drop in platelets. Seek urgent care if these appear.
Is Quinine safe to take?
For most people it is safe when taken exactly as a doctor or pharmacist advises and as printed on the label. Tell your clinician about your other medicines and health conditions, and seek urgent care for any serious reaction.

Related conditions

Related medicines

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