Pregabalin and Gabapentin are non-natural, branched chain amino acids. Both are chemical analogues of gama-aminobutyric acid (GABA); however, neither drug has activity in GABAergic neuronal systems. Both these drugs are efficacious in certain types of neural pain control.

Dosage: The treatment for neuropathic pain with Gabapentin is usually initially started with one dose of 300 mg per day.It can be given orally at a dose of 300-1200 mg 3 times per day. Maximum dose should be 3600 mg per day.

The suggested maximum therapeutic dose of Pregabalin in neuropathic pain associated with diabetic peripheral neuropathy is 300 mg per day; it can be initiated at a dose of 50 mg thrice a day. The dose of the drug can be increased up to 300 mg per day within a week of starting the treatment. 

For neuropathic pain associated with spinal cord injury, the recommended therapeutic dose of Pregabalin should be 150 to 600 mg daily. The suggested starting dose is 75 mg twice per day. The dose might be increased to 150 mg twice/day within one week of starting treatment. In patients having suboptimal pain relief after 2 to 3 weeks of treatment with 150 mg twice daily, the dose might be increased up to 300 mg twice/day.^[1]

Excretion: It is estimated that elimination half-life parameter for the two drugs are same. The elimination half-life for Gabapentin is estimated to be in the range of 5-7 hours, and that for Pregabalin is about 6.3 hours, indicating that both drugs can reach a steady state within 24-48 hours.

Adverse effects: Generally, Pregabalin and Gabapentin are well tolerated. Dizziness is the most frequently reported negative effect of Pregabalin, followed by somnolence, which accounts for the most frequent reason for treatment discontinuation. The negative effects of both the drugs are dose-dependent and are reversible.