Comparative Pharmacology
Head-to-head clinical analysis: ETRAFON 2 25 versus LOXITANE IM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ETRAFON 2 25 versus LOXITANE IM.
ETRAFON 2-25 vs LOXITANE IM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of perphenazine (a typical antipsychotic) and amitriptyline (a tricyclic antidepressant). Perphenazine blocks postsynaptic dopamine D2 receptors in the mesolimbic system, also antagonizes alpha-adrenergic, histaminergic, and muscarinic receptors. Amitriptyline inhibits reuptake of serotonin and norepinephrine at the presynaptic neuronal membrane, enhancing serotonergic and noradrenergic neurotransmission.
LOXITANE IM (loxapine) is a dibenzoxazepine antipsychotic. Its mechanism of action is not fully established but is thought to be mediated via antagonism of central dopamine D2 and serotonin 5-HT2A receptors. It has high affinity for D2, D3, D4, and 5-HT2A receptors and low affinity for D1 receptors. It also has moderate affinity for histamine H1 and alpha1-adrenergic receptors.
One tablet (2 mg perphenazine, 25 mg amitriptyline) orally three or four times daily. Maintenance: 2-4 tablets daily.
Adults: 12.5-50 mg IM every 4-6 hours as needed, not to exceed 150 mg/day.
None Documented
None Documented
Perphenazine: 8-12 hours (terminal); amitriptyline: 15-24 hours (terminal), with nortriptyline active metabolite half-life 18-44 hours. Steady-state achieved in 4-7 days.
Terminal elimination half-life: 8-12 hours. Clinically, steady-state reached in 2-3 days; dosing interval based on q6-12h.
Renal: approximately 25-50% as metabolites and unchanged drug; biliary/fecal: 10-25% as metabolites; the remainder is extensively metabolized via hepatic pathways.
Primarily renal: 70% as metabolites; biliary/fecal: 30% as metabolites and unchanged drug.
Category C
Category C
Antipsychotic/Antidepressant Combination
Antipsychotic