Quinine – QT prolongation risk & interactions

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