When a patient complains of severe pruritus at first presentation, consider pharmacotherapy in conjunction with nonpharmacotherapeutic options. Several of the more effective topical therapies for pruritusa are listed in TABLE 4.20 Well-known systemic agents for this purpose are reviewed below and listed in TABLE 5.7
Systemic treatment
Antihistamines. A staple in the treatment of pruritus for many years, antihistamines are not effective for all causes; however, they are effective in treating paraneoplastic pruritus.20 First-generation antihistamines, with their sedating effect, can be useful for patients who experience generalized pruritus at night.20
Anticonvulsants. Gabapentin and pregabalin are analogs of the neurotransmitter gamma-aminobutyric acid.20 This drug class is helpful in neuropathic pruritus specifically caused by impingements, such as brachioradial pruritus and notalgia paresthetica.20 In addition, of all systemic therapies used to treat uremic pruritus, gabapentin has, in clinical trials, most consistently been found effective for uremic pruritus.6 (Note: Use renal dosing of gabapentin in patients with renal failure.)
Antidepressants. Selective serotonin reuptake inhibitors (SSRIs; eg, fluvoxamine, paroxetine, and sertraline) might cause itch to subside by increasing the serotonin level, which, in turn, works to decrease inflammatory substances that cause itch.7 SSRIs have been used to treat patients with psychogenic pruritus, cholestatic pruritus, and paraneoplastic pruritus.7
Tricyclic antidepressants (eg, amitriptyline and doxepin) lessen the itch by antagonizing histamine receptors and through anticholinergic mechanisms. Tricyclics are best used in the treatment of psychogenic and nocturnal itch.7
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