Gabapentin is licensed for use in neuropathic pain of any cause:
- increase the dose according to the following regimen: 300 mg on day 1, then 300 mg twice daily on day 2, then 300 mg 3 times daily on day 3, then increase according to response in steps of 300 mg daily (in 3 divided doses) to max. 1.8 g daily
- in trials pain scores show that shows that gabapentin reduces pain and improves some quality-of-life measures in patients with a wide range of neuropathic pain syndromes (Serpell, Pain 2002, 99(3):557-66)
Carbamazepine and phenytoin are licensed for the treatment of trigeminal neuralgia:
- phenytoin is reserved for patients who fail to respond to carbamazepine
- trial evidence supports carbamazepine rather than phenytoin
For NICE guidance regarding management of chronic pain (pain that lasts for more than 3 months) then see linked item.
In this guidance (4), NICE state that antiepileptic drugs including gabapentinoids should not be initiated to manage chronic primary pain in people aged 16 years and over.
Notes:
- when withdrawing or switching treatment, taper the withdrawal regimen to take account of dosage and any discontinuation symptoms (3)
- MHRA advice on valproate: In April 2018, we added warnings that valproate must not be used in pregnancy, and only used in girls and women when there is no alternative and a pregnancy prevention plan is in place. This is because of the risk of malformations and developmental abnormalities in the baby (3)
- because of a risk of abuse and dependence, pregabalin and gabapentin are controlled under the Misuse of Drugs Act 1971 as class C substances and scheduled under the Misuse of Drugs Regulations 2001 as schedule 3 (as of 1 April 2019) (3)
Reference: