Researchers have called for greater vigilance among clinicians prescribing pregabalin for pain, after their figures showed a 10-fold rise in ambulance attendances related to its misuse.

Of particular concern was a finding that two-thirds of pregabalin-related ambulance call-outs were for people who had also used sedatives, putting then at high risk of harm, said addiction researchers from Monash University, Victoria

In a retrospective analysis of ambulance call outs in Victoria, they found pregabalin-related attendances increased from 0.28 cases per 100,000 population to 3.32 cases per 100,000 between 2012 and 2017, with a total of 1,201 call-outs.

The ten-fold rise in ambulance attendances correlated strongly with the rise in pregabalin prescribing in Australia, where PBS prescription numbers had risen from 678,000 in 2013 – the first year it was listed for use in neuropathic pain –  to 3.7 million in 2017.

Almost 90% of people involved in pregabalin attendances required transport to hospital, usually because they had combined the drug with sedatives such as benzodiazepines, alcohol or opioids and had life-threatening respiratory or CNS depression.

Writing in the MJA, the study authors said it was also notable that in almost half the cases the pregabalin users had contraindications to its use such as a history of drug or alcohol misuse or psychiatric problems.

“Clinicians should ensure that consumers are aware of the risks of these interactions, and be particularly cautious when considering prescribing pregabalin for patients who are taking other sedatives. They should also direct patients to the NPS MedicineWise guidelines on how to safely take pregabalin

The study was unable to say whether the pregablin involved in cases of misuse was obtained on prescription or by diversion or other illegal means.

“Nevertheless, our findings suggest that there is a group of people who are likely to misuse pregabalin, and may be at risk of its undesirable psychiatric side effects. Clinicians should carefully review the indications for prescribing pregabalin and remind patients that it is illegal to give their medications to other people,” the researchers said

They suggested Australia may need to follow other jurisdictions that are taking active steps to regulate pregabalin availability because of misuse, such as the UK reclassifying it as a controlled drug. They also call for pregabalin to be included in the real-time prescription monitoring programs being rolled out at state level.