Management issues in neuropathic pain
Neuropathic pain is a common complication to cancer, cancer treatment, HIV, and other conditions that may affect the somatosensory nervous system. Neuropathic pain may be present in up to 40% of cancer patients and may persist independently of the cancer and affect the quality of life in disease-free cancer survivors. Particular surgical treatment and chemotherapy may cause chronic persistent neuropathic pain in cancer survivors. The diagnosis of neuropathic pain can be challenging and requires documentation of a nervous system lesion and pain in areas of sensory changes. The pharmacological treatment may include tricyclic antidepressants, selective serotonin noradrenaline reuptake inhibitors (duloxetine or venlafaxine), calcium channel α2↓ agonists (gabapentin or pregabalin), and opioids. Topical lidocaine and capsaicin, NMDA antagonists, carbamazepine, oxcarbazepine, and cannabinoids may be indicated. Due to limited efficacy or intolerable side effects at maximal doses, combination therapy is often required and careful monitoring of effect and adverse reactions is important.