DRUG CLASS: Gabapentin –an anticonvulsant, Nortriptyline –tricyclic anti-depressant

MECHANISM OF ACTION:

 Gabapentin - Gabapentin crosses several lipid membrane barriers via system L amino acid transporters. In vitro, gabapentin modulates the action of the GABA synthetic enzyme, glutamic acid decarboxylase (GAD) and the glutamate synthesizing enzyme, branched-chain amino acid transaminase.

Nortriptyline - Traditionally believed to increase the synaptic concentration of serotonin and/or norepinephrine in the central nervous system by inhibition of their reuptake by the presynaptic neuronal membrane. Inhibits the activity of histamine, 5-hydroxytryptamine, and acetylcholine. 

It increases the pressor effect of norepinephrine but blocks the pressor response of phenethylamine. However, additional receptor effects have been found including desensitization of adenyl cyclase, down regulation of beta-adrenergic receptors, and down regulation of serotonin receptors.

INDICATIONS & DOSAGE:  As Directed by the Physician