Summary Safety Review - Gabapentin - Assessing the Potential Risk of Serious Breathing Problems

September 16, 2016

Product

Gabapentin

Potential Safety Issue

Serious breathing problems (respiratory depression)

Key Messages

• Gabapentin belongs to the family of medicines called antiepileptic drugs and is used for treating epilepsy (seizures).
• While reviewing information provided by the manufacturer, Health Canada found cases of serious breathing problems in patients treated with gabapentin.
• Health Canada's review concluded that there is evidence supporting a risk of serious breathing problems when gabapentin is used. Health Canada recommended updates to the product information for gabapentin to warn about this risk.

Overview

In 2014, the product information for gabapentin products was updated to warn about the risk of serious breathing problems (respiratory depression) when it is used with an opioid. While reviewing safety information given by the manufacturer for this change, Health Canada found cases of respiratory depression in patients treated with gabapentin alone. Therefore, this current safety review was carried out to assess the possibility of the same concerns in patients using gabapentin alone (when not taken with opioids) and to find out if more safety measures were needed.

Use in Canada

• Gabapentin belongs to the family of medicines called antiepileptic drugs and is used for treating epilepsy (seizures) when other treatments have not worked.
• Gabapentin has been marketed in Canada since 1994 under the brand name Neurontin and generic products are also available. It is available by prescription only. In 2015, approximately 3.9 million prescriptions (new and refills) were filled.

Safety Review Findings

• At the time of the review, Health Canada received 1 Canadian report^a where gabapentin use was considered related to respiratory depression.
• Health Canada is aware that in other countries gabapentin has approved uses other than for the treatment of epilepsy.
• The review gathered an additional 20 international reports related to serious breathing problems associated with gabapentin use from the scientific and medical literature as well as information received from drug manufacturers. In these reports, the drug was used in some patients for treating epilepsy and in other patients for other uses including pain management. Some reports described that when the patient stopped using gabapentin the breathing problems went away and when the medication was restarted the breathing problems reappeared. This finding supports that gabapentin use may have contributed to the side effects.
• The review also found that patients having lung, kidney or nervous system diseases that impact breathing, as well as those that are elderly, or using other drugs that can affect breathing are at higher risk of serious breathing problems.

Conclusions and Actions

• Health Canada's safety review concluded that there is evidence of a link between the use of gabapentin, in general, and the risk of serious breathing problems.
• Health Canada will work with manufacturers to update the product information to further warn about the risk of serious breathing problems. Health Canada will also issue a notice in the Health Product InfoWatch when the product information is updated.
• Health Canada continues to monitor safety information involving gabapentin, as it does for all health products on the Canadian market, to identify and assess potential harms. Health Canada will take appropriate and timely action if and when any new health risks are identified.

Additional Information

The analysis that contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what is known about the use of this drug both in Canada and internationally.

For additional information, contact the Marketed Health Products Directorate.

References