Pharmacotherapy of neuropathic pain
| Medications | Mechanism of action | Side-effects | Caution |
| Tricyclic antidepressants: amitriptyline, imipramine, clomipramine | Inhibition of monoamine reuptake, blocking of Na channels, action on β2 receptors | Anticholinergic effects, urinary retention especially with BPH, xerostomia, cardiac conduction anomalies, confusion and sedation | Consider presence of underlying cardiac pathology, QT prolongation Glaucoma |
| Serotonin–norepinephrine reuptake inhibitor antidepressants: venlafaxine, duloxetine | Serotonin–norepinephrine reuptake inhibition | Nausea and vomiting, xerostomia and weight gain | If used with tramadol or tapentadol, risk of serotoninergic syndrome Caution when used with liver disease and with hypertension |
| Anticonvulsant calcium channel α-2-δ subunit agonists or gapentinoids: gabapentin, pregabalin | Widely approved, available and utilised for the treatment of neuropathic pain | Sleepiness, negative impact on cognitive function, weight gain, peripheral oedema, especially in the lower extremities | Decrease dose with renal dysfunction |
| Topiramate | Inhibition of γ-aminobutyric acid (GABA)-mediated neurotransmission NMDA antagonist | Also acts on carbonic anhydrase inhibitor with potential risk of nephrolithiasis and acute angle glaucoma Anorexia and possible weight loss Negative effect on cognition | Decrease dose with renal dysfunction |
| Topical preparations: lidocaine patches/ointments, capsaicin patches/ointments | Na channel blocker Substance P depletion from nociceptors TRPV1 (transient receptor potential channel vanilloid agonist) | Erythema, pruritus | Do not apply on open sores High strength 8% formulation used in the management of post-herpetic neuralgia; very painful to apply and rarely needed in cancer pain |
BPH: benign prostate hypertrophy; NMDA: n-methyl-D-aspartate.