Aimee Etherington

Neuropathic pain is a growing public health issue that affects approximately twelve percent of adults (Sicras-Mainar, Rejas-Gutiérrez, Pérez-Páramo, & Navarro-Artieda, 2016). Individual responses to treatment vary, with only forty to sixty percent of people experiencing therapeutic effects from medication and most requiring a combination of drugs (Bannister et al., 2017). This condition is predicted to increase in the future (Cruccu & Truini, 2017). To uphold the quality of life of people with neuropathic pain, it is essential that the most effective therapy is prescribed. Pregabalin and gabapentin are two drugs within the same family that can be used to treat neuropathic pain. This essay will compare their pharmacological parameters to ascertain which drug is more appropriate for people with this condition.

Pregabalin and gabapentin are both gabapentinoids and therefore have similar mechanisms of action. Bannister et al. (2017) explain that they were developed to be GABA analogues. However, neither binds to GABA receptors. It is not fully understood how they produce an analgesic effect, but it has been established that both drugs bind to the α₂δ subunit of neuronal voltage-gated calcium channels. This subunit is up-regulated after nerve injury. When gabapentinoids bind to the subunit, the release of certain excitatory neurotransmitters such as glutamate, calcitonin gene-related peptide, and substance P is reduced (Calandre, Rico-Villademoros, & Mahmoud, 2016). Because nerve injury causes neuronal hyperexcitability which leads to neuropathic pain, the reduction of these neurotransmitters produces an analgesic effect.

Although they are in the same mechanistic class, pregabalin and gabapentin can produce different therapeutic responses (Markman et al., 2017). The effects of pregabalin in neuropathic pain has been studied more in depth than gabapentin’s. Perhaps this is because gabapentin was used as an anticonvulsant until its analgesic effects were discovered. Neither of these drugs can relieve pain from mechanical and heat sources (Bannister et al., 2017). Kremer et al. (2017) suggests that this is perhaps because they do not act on the body’s opioid system. However, these authors do point out that gabapentin may produce an anti-inflammatory effect by reducing pro-inflammatory cytokines’ expression. It has not been established whether pregabalin is capable of this.