A Drug Safety Update, issued by MHRA in October 2017, advises of the risk of severe respiratory depression in patients taking gabapentin, even without concomitant opioids.

Gabapentin is an anti-epileptic drug that is clinically indicated for:

  • partial seizures with and without secondary generalization
  • peripheral neuropathic pain such as painful diabetic neuropathy and post-herpetic neuralgia in adults.
Risk of respiratory depression

Reports of patients suffering respiratory depression following use of gabapentin without concomitant use of opioids triggered a European review of gabapentin. This review recommended that product information for gabapentin should be updated to include warnings for severe respiratory depression, the quoted frequency is rare (affecting up to 1 in 1000 patients post marketing).

In the UK 50 yellow card reports were submitted between 19th February 1996 and 1st September 2017 advising of cases of respiratory depression or breathing difficulties in patients taking gabapentin. Of these cases, 17 reports included opioids as concomitant or possibly contributory medicines.

The patient information leaflet for gabapentin products is being updated to include warnings about breathing problems which if severe may require emergency treatment. Patients should be advised of the possibility of this adverse reaction and that if they experience difficulty breathing they should seek medical help.

Patients most at risk of respiratory depression include:

  • elderly patients,
  • patients taking CNS depressants
  • patients diagnosed with:
    • Compromised respiratory function
    • Respiratory disease
    • Neurological disease
    • Renal impairment

Dose reductions may be clinically appropriate in these patient groups to minimise the risk of severe respiratory depression.

Risk associated with concomitant use of opioids

Healthcare professionals should be alert to the increased risk of respiratory depression when gabapentin is used in conjunction with opioid medicines. These patients should be closely observed for signs of CNS depression, such as drowsiness, sedation, and respiratory depression. Patients showing signs of respiratory depression may require the dose of either gabapentin or the opioid to be reduced.

Advice for healthcare professionals
  • Be aware of the risk of CNS depression, including severe respiratory depression, with gabapentin
  • Consider whether dose adjustments might be necessary in patients at higher risk of respiratory depression, including elderly people, patients with compromised respiratory function, respiratory or neurological disease, or renal impairment, and patients taking other CNS depressants
  • Report any suspected adverse reactions on a yellow card yellowcard.mhra.gov.uk/