Tricyclic antidepressant (TCA)
Inhibits reuptake of norepinephrine and serotonin; also has significant antagonism at muscarinic, histamine H1, and alpha-1 adrenergic receptors.
Major depressive disorder (MDD), childhood enuresis
Panic disorder, neuropathic pain, post-traumatic stress disorder (PTSD), augmentation in treatment-resistant depression
Oral tablets
Start at 25–50 mg p.o. daily, given at bedtime or in divided doses; titrate gradually based on response and tolerability
75–200 mg/day for adults (lower pediatric dosing for enuresis, age-dependent)
Metabolized by CYP2D6 and CYP2C19; active metabolite (desipramine); half-life ~11–25 hours
Dry mouth, constipation, urinary retention, blurred vision, dizziness, sedation, weight gain
Cardiac conduction abnormalities, orthostatic hypotension, seizures, delirium, overdose toxicity
Baseline ECG for patients over age 40 or with cardiac history; monitor for orthostasis, anticholinergic burden, and suicidal ideation
Increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults
Use with caution in patients with dementia, post-stroke cognitive impairment, or traumatic brain injury (TBI) due to heightened risk of confusion, delirium, and falls from anticholinergic and hypotensive effects. ECG screening is recommended prior to initiation in adults over 40 or those with cardiac risk factors.