Quinine – QT prolongation risk & interactions

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Despite repeated warnings about an unfavourable balance between risks and benefits, prescribing of quinine salts in NECS stakeholder CCGs has remained remarkably constant in recent years.

The MHRA have issued a reminder about the potential for quinine to effect the QT interval,  along with updated information about interactions – particularly with anticonvulsant drugs.

Advice for healthcare professionals:

  • be aware of dose-dependent effects on the QT interval and use caution if prescribing quinine in patients:
    • with conditions that predispose to QT prolongation such as pre-existing cardiac disease or electrolyte disturbance
    • taking other medicines that could prolong the QT interval
    • with atrioventricular block
  • monitor patients closely if administration of quinine with phenobarbital or carbamazepine is necessary; serum levels of these anticonvulsant medicines could become raised and cause anticonvulsant toxicity
  • consult the Summary of Product Characteristics for a full list of interacting medicines and potential adverse reactions
  • report suspected adverse drug reactions with quinine on a Yellow Card