Gabapentin (Neurontin®, Gralise®)

Overview

Gabapentin is a neuronal calcium channel blocker and GABA synthesis/degradation modulator used in the treatment of epilepsy involving non-generalizing partial seizures, as well as post-herpetic neuralgia (PHN).  The mechanisms of gabapentin-mediated analgesia and antiepileptic activity are not completely understood, although the drug appears to inhibit presynaptic voltage-gated calcium channels, decrease neuronal excitability, and reduce spurious synaptic activity.  Gabapentin also stimulates GABA synthesis via activation of the glutamate decarboxylase enzyme, and inhibits GABA degradation by antagonizing GABA transaminase. This increases synaptic GABA levels,  raises the seizure threshold, and inhibits pain signal transduction in peripheral nociceptive pathways.

Gabapentin, like other anti-epileptic medications, has been linked to a higher risk of suicidal thoughts following initiation of therapy.  Patients receiving anti-epileptic therapies should be monitored for worsening depression and other adverse psychiatric effects.  More common side effects include somnolence and GI upset.

Gabapentin has off-label uses in other conditions including fibromyalgia, non-PHN neuropathic pain, and alcohol dependence.

In Plain English

Gabapentin reduces excessive electrical activity in the brain,  as well as in nerves that transmit pain.  This can help control seizures and certain painful conditions.

Clinical Considerations

gabapentin

Figure 1. Gabapentin clinical considerations at a glance

 

Evidence Basis

 

Gabapentin In the News

  • 2018 CBS News: https://www.cbsnews.com/news/gabapentin-opioid-alternative-doctors-warning-about-drug/

 

Citations

  1. Wishart DS, Feunang YD, Guo AC, Lo EJ, Marcu A, Grant JR, Sajed T, Johnson D, Li C, Sayeeda Z, Assempour N, Iynkkaran I, Liu Y, Maciejewski A, Gale N, Wilson A, Chin L, Cummings R, Le D, Pon A, Knox C, Wilson M. DrugBank 5.0: a major update to the DrugBank database for 2018. Nucleic Acids Res. 2017 Nov 8. doi: 10.1093/nar/gkx1037
  2. Epocrates Rx Online [Internet database]. San Mateo (CA): Epocrates, Inc. 2003. Retrieved at mobile.epocrates.com. Web-based; continuous content updates. Accessed 2018 May 11.
  3. “Prescription Prices, Coupons & Pharmacy Information – GoodRx.” Prescription Prices, Coupons & Pharmacy Information – GoodRxhttp://www.goodrx.com
  4. “DailyMed.” U.S. National Library of Medicine, National Institutes of Health, dailymed.nlm.nih.gov/dailymed/.

 

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