Pregabalin ๐
Always check the BNF link here before prescribing.
- ๐ Pregabalin is an anticonvulsant and analgesic, used as adjunctive therapy in seizures and neuropathic pain.
- Structurally related to GABA, but does not bind GABA receptors; instead it modulates calcium channels.
- Renally excreted (dose adjustment required in renal impairment).
โ๏ธ Mode of Action
- Binds to the ฮฑ2ฮด subunit of presynaptic voltage-gated calcium channels.
- โก๏ธ Reduces calcium influx โ โ release of excitatory neurotransmitters (glutamate, substance P, noradrenaline).
- Results in anticonvulsant, anxiolytic, and analgesic effects.
๐ Indications
- Adjunctive therapy in partial seizures.
- Management of neuropathic pain (e.g. post-herpetic neuralgia, diabetic neuropathy).
- Generalised anxiety disorder (GAD) (licensed indication in the UK).
๐ Dose
- Start: 25 mg BD, titrate upwards.
- Maintenance: 150โ600 mg/day, divided BD (sometimes TDS).
- Adjust dose in renal impairment (reduced clearance).
๐ Interactions
- Few clinically significant interactions (not metabolised by liver enzymes).
- โ ๏ธ Additive sedation when combined with other CNS depressants (opioids, benzodiazepines, alcohol).
โ Contraindications / Cautions
- See BNF for full details.
- Caution in renal impairment (dose adjustment needed).
- Monitor for misuse/abuse โ pregabalin is a Schedule 3 controlled drug in the UK.
โ ๏ธ Side Effects
- ๐ Dizziness, ataxia, drowsiness.
- ๐ง Memory disturbance, attention deficit, mood changes.
- ๐ฎโ๐จ Weight gain, oedema, blurred vision.
- GI: dry mouth, nausea, constipation.
- Musculoskeletal: myalgia, asthenia.
- Rare: liver or pancreatic disturbance, skin rashes.
- โ ๏ธ Reports of euphoria, dependence, and withdrawal on abrupt cessation.
๐ Clinical Pearls
- Pregabalin is often preferred over gabapentin for faster titration and more predictable absorption.
- In GAD, pregabalin can be considered when SSRIs or SNRIs are ineffective or not tolerated.
- Discontinue gradually over โฅ1 week to reduce risk of withdrawal seizures and rebound anxiety.
- Check renal function regularly, especially in elderly patients.
๐ References
