UK Clinical Pharmacy Association

Quinine

This monograph does not cover the use of quinine as an antimalarial

Issues for surgery

Nocturnal leg cramps if omitted.

Potential interaction with suxamethonium if continued (see Interactions with common anaesthetic agents).

Risk of QT-interval prolongation if continued (see Interactions with common anaesthetic agents and

Interactions with other common medicines used in the perioperative period).

Advice in the perioperative period

Elective and emergency surgery 

Continue if needed for symptomatic relief of leg cramps.

Post-operative advice

Restart post-operatively, if needed, once enteral intake resumed.

Interactions with common anaesthetic agents

Suxamethonium

The manufacturers advise quinine enhances the neuromuscular effects of suxamethonium. An isolated case report describes recurarisation (increase in neuromuscular block after period of recovery) and apnoea when intravenous quinine was given after reversal of neuromuscular blockade in a patient who had also been given gentamicin. The reason for the reaction is not fully understood but bear in mind the need to be alert for signs of recurarisation in patients given drugs possessing some neuromuscular blocking activity, particularly during the recovery period.

QT-interval prolongation

Quinine prolongs the QT-interval in a dose-dependent manner. Co-administration with other medicines known to prolong the QT-interval must be based on careful assessment of the potential risks and benefits for each patient.

Anaesthetic agents that may be used in the perioperative period that are known to, or predicted to, prolong the QT-interval include:

  • desflurane, isoflurane, sevoflurane - avoid
  • thiopental*

*monitor ECG with concurrent use if risk factors for QT-prolongation are also present (increasing age, female sex, cardiac disease, and some metabolic disturbances, e.g. hypokalaemia).

Interactions with other common medicines used in the perioperative period.

Hypokalaemia

Dexamethasone and hydrocortisone may cause hypokalaemia, increasing the risk of torsades de pointes, which might be additive with the effects of quinine – monitor serum potassium concentrations.

QT-interval prolongation

Quinine prolongs the QT-interval in a dose-dependent manner. Concurrent use with other medicines that can prolong the QT-interval might increase the risk.

Medicines that may be used in the perioperative period that are known to prolong the QT-interval include:

  • ciprofloxacin*
  • clarithromycin*
  • domperidone – avoid
  • droperidol – avoid
  • erythromycin (particularly intravenous)*
  • granisetron – avoid if risk factors
  • haloperidol – avoid
  • loperamide*
  • ondansetron – avoid
  • prochlorperazine (theoretical risk)*

*monitor ECG with concurrent use if risk factors for QT-interval prolongation also present (increasing age, female sex, cardiac disease, and some metabolic disturbances, e.g. hypokalaemia)

Ototoxicity

Concomitant use of quinine and aminoglycosides e.g. gentamicin, vancomycin may increase the risk of ototoxicity.

Whilst single surgical prophylactic doses should not pose a problem, continued post-operative treatment may require close monitoring

Further information

Quinine bisulphate tablets contain less quinine than the same dose of quinine sulfate, however, this is not clinically significant for nocturnal leg cramps. It is common practice to use the two preparations interchangeably within the hospital setting, dependent on local stock holdings.

References

Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 19th June 2024]

Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 19th June 2024]

Summary of Product Characteristics – Quinine Sulphate 200mg Tablets. Strides Pharma UK Ltd. Accessed via www.medicines.org.uk 19/06/2024 [date of revision of the text July 2022]