Pregabalin (Psychiatric Use — GAD)

How it works

It binds the alpha-2-delta subunit of voltage-gated calcium channels, reducing presynaptic calcium influx and the release of excitatory neurotransmitters, which dampens neuronal excitability relevant to anxiety.

Prescribing in practice

• It is a controlled drug with recognised dependence and misuse potential, so assess risk before prescribing, especially in people with a history of substance misuse.
• There is an MHRA warning about serious, potentially fatal respiratory depression when combined with opioids or other CNS depressants, particularly in the elderly or those with respiratory compromise.
• Discontinue gradually to avoid withdrawal symptoms, and reduce the dose in renal impairment as it is renally cleared.

Monitoring

Monitor anxiety response, mood and suicidal ideation, sedation, signs of misuse or dependence, and adjust for renal function as needed.

Counselling the patient

• Do not stop suddenly; the dose should be tapered to avoid withdrawal effects.
• It can cause drowsiness and dizziness, so take care with driving and avoid combining with alcohol or other sedatives.
• Tell your prescriber about any history of dependence and report breathing problems if you also take opioids.

Evidence & guidelines

NICE recommends pregabalin as a treatment option for generalised anxiety disorder when an antidepressant is unsuitable or has not worked, with MHRA cautions on dependence and respiratory depression.