Tacrolimus-induced generalized tremor with excellent response to primidone

Tacrolimus treatment is associated with a range of neurological adverse effects. Neurotoxicity caused by tacrolimus may result in subacute onset of tremor in a subset of patients. The commonly reported tremor phenomenology associated with tacrolimus neurotoxicity is the action tremor of bilateral upper limbs with or without rest tremor. Tremor may occur even if the plasma concentration of tacrolimus is within the therapeutic range. In this report, we highlight a case of tacrolimus-induced tremor, in which, in addition to having action and rest tremor of the upper limbs, the patient had vocal, lingual, and lower limb tremor. We demonstrate how drug cessation and temporary administration of primidone remarkably improved the tremor.