Pregabalin: Alpha-2-Delta Ligand for Neuropathic Pain and Epilepsy
Pregabalin (Lyrica) binds to the alpha-2-delta (α₂δ) subunit of voltage-gated calcium channels in the CNS, reducing the release of excitatory neurotransmitters. It is approved for neuropathic pain, epilepsy (adjunct), fibromyalgia, and generalised anxiety disorder (EU).
Despite structural similarity to GABA, pregabalin does not bind GABA receptors. It is a Schedule V substance in the US; in Germany some formulations require BtMVV prescription.
Mechanism of Action
Pregabalin binds with high affinity to the α₂δ subunit, reducing calcium influx at nerve terminals. This decreases release of glutamate, substance P, and CGRP — dampening central sensitisation underlying neuropathic pain and anxiety states.
Indications & Use
Peripheral and central neuropathic pain (diabetic neuropathy, postherpetic neuralgia, spinal cord injury pain), adjunct therapy for partial onset seizures, fibromyalgia, and generalised anxiety disorder (EU approval).
Dosage
Neuropathic pain: start 75 mg twice daily or 50 mg three times daily; increase to 150 mg twice daily within 1 week. Maximum 600 mg/day. Dose reduction mandatory for creatinine clearance <60 mL/min — proportional to renal function.
Side Effects
Very common: dizziness, somnolence (especially at initiation). Common: weight gain, peripheral oedema, ataxia, blurred vision, memory impairment, dry mouth. Rare but serious: angioedema, suicidal ideation.
Drug Interactions
CNS depressants, opioids, benzodiazepines: additive sedation and respiratory depression. Alcohol potentiates CNS effects. No significant CYP450 interactions. ACE inhibitors: possible increased angioedema risk.
Contraindications
Hypersensitivity to pregabalin. Caution: renal impairment (dose reduction required), history of substance misuse, congestive heart failure, elderly patients at fall risk.
Frequently Asked Questions
Is pregabalin the same as gabapentin?
Both bind the α₂δ subunit. Pregabalin has more predictable linear pharmacokinetics, ~90% oral bioavailability (vs. ~60% for gabapentin), and more approved indications including fibromyalgia and GAD.
Does pregabalin cause weight gain?
Yes — approximately 5–10% of patients gain weight due to increased appetite and fluid retention. Monitor weight during long-term treatment.
How do I stop pregabalin safely?
Taper over at least 1 week. After prolonged use, a slower taper (several weeks) minimises withdrawal symptoms such as insomnia, nausea, and anxiety.
References
- EMA EPAR — Lyrica (pregabalin)
- NICE Guideline NG173: Chronic Pain
- EFNS Guidelines on Neuropathic Pain
Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice.