Pregabalin and gabapentin are to have enhanced warnings added to the Product Information (PI) and Consumer Medicine Information (CMI) to advise about the risks of misuse.
The TGA is adding Boxed Warnings to advise that pregabalin poses a risk of misuse, while both pregabalin and gabapentin pose risks of abuse and dependence.
The products are indicated for neuropathic pain and epilepsy, have previously raised concerns about risks for misuse and addiction.
Prescribers are advised in the new warnings to assess a patient’s risk of misuse before prescribing pregabalin and to check for history of substance use disorder and signs of abuse or dependence before prescribing pregabalin or gabapentin.
“Monitor patients regularly during treatment, particularly among patients with current or past use of opioids and/or benzodiazepines. In particular, monitor for increases in dosing or drug-seeking behaviours,” the TGA advises health professionals.
The TGA also advises caution when prescribing pregabalin or gabapentin concomitantly with drugs such as opioids due to risk of CNS depression
It says patients who require concomitant treatment with CNS depressants, including opioids, should be carefully observed for signs of CNS depression, such as somnolence, sedation and respiratory depression.
“The decision to impose the Boxed Warnings has been taken after TGA investigation of continuing reports of misuse associated with pregabalin, and abuse and dependence associated with both pregabalin and gabapentin in Australia,” the advisory statement says.
In 2019, a TGA review noted that off-label use of gabapentinoids was occurring for non-neuropathic pain and generalised anxiety disorder. Adverse events reports to the TGA – including deaths – showed there was a a safety signal for the harmful and hazardous use of gabapentinoids.
The Advisory Committee on Medicines (ACM) found that pregabalin appeared to have a higher addictive potential than gabapentin because it is more rapidly absorbed, has a higher affinity for the α2‐δ subunit of presynaptic voltage‐gated calcium channels, and has a longer half‐life. It also accepted evidence that one in seven Australians dispensed pregabalin appeared to be at high risk of misuse.
A previous TGA advisory notice warned of the risk of suicidality with pregabalin.