Amoxapine
Tricyclic antidepressant (norepinephrine, serotonin reuptake inhibitor; dopamine D2 antagonist; metabolite of the antipsychotic loxapine)
- Major Depression
Features
Dosing
Start 25mg 1 po qhs x4days, 2 po qhs x4days, 3 po qhs x4days then 1 po qam, 3 po qhs; then (start in 16 days) 100mg 2 po qhs
Management
Like maprotiline this tetracyclic is unique in having some dopamine-blocking properties, giving it the unfortunate side effect profile of an antipsychotic (EPS).
TOLERABILITY: ANTICHOLINERGIC: Constipation (treat docusate 100 mg BID + sennosides 8.6 mg; bethanechol 10-25 mg tid if severe), urinary retention (treat bethanechol 25mg tid), dry mouth (treat spry gum tid, biotene; or pilocarpine swish), blurry vision, confusion.
RISKS: HEART: Orthostatic hypotension (treat elastic abdominal binders or support stockings; if severe, fludrocortisone 0.1-0.2 mg qd or midrodine 0.5 mg tid), falls, cardiac arrhythmias; HEPATOTOXICITY: Extremely rare (4 per 100,000 patient-years).
EMR Text
Depression
Amoxapine use based on FDA approval in major depressive disorder.
Amoxapine side effects, including cardiac, hypotension, and hepatotoxicity, reviewed with patient.