perphenazine TRILAFON

Class: First Generation Antipsychotic/​Phenothiazine
FDA Indications: Schizophrenia, Behavioral Complications In Patients With Mental Retardation
Off-Label Use: Bipolar Mania
Prescribing
Forms: 2, 4, 8, 16mg tablet; 5mg/mL IM
Dose Range: 0.5-40 mg/day
Starting: 4mg bid for 5-7 days then, if tolerated, 4 mg/day + 8 mg qhs, ↑ thereafter by 4 mg q 5-7 days
Therapeutic: 24 mg (as 8 + 16) in most instances In cases of poor response, can be increased to 32mg (as 12 + 20 or 8 + 8 + 16) but think of increasing frequency first
Stopping: Taper 6-8 weeks, rapid d/c can lead to rebound psychosis
Monitoring:

NAMI drug fact sheet

Precautions
Contraindications: In patients with suspected or established subcortical brain damage, in patients receiving large doses of hypnotics, and in comatose or severely depressed states. Phenothiazines are contraindicated with significant hepatic impairment.
Serious Side Effects: , , , Cardiac Arrhythmias, Neutropenia and/or Agranulocytosis (rare), Hyperprolactinemia
Side Effects: dizziness, visual changes, constipation, orthostatic hypotension, EPS, drowsiness
Pharmacodynamics
1° MOA: Dopamine 2 (D2) Receptor Antagonism In Mesolimbic Area
Target: D2 (high), 5HT2 (very high), H1 (high), α1 (high), M1 (minimal)
Pharmacokinetics
t½: 9.4 (8-12)° TMAX: 1-3°
Substrate of: 2D6; 1A2
Inhibits: 2D6 (weak); Induces:
Active Metabolites: N-Desmethylperphenazine, 7-Hydroxyperphenazine
DDIs
Misc
  • - intermediate-potency
  • - long-established use high margin of safety
  • - has no significant anticholinergic action and ∴ ↓ risk of sedation and orthostatic hypotension
  • - although well known to promote EPS at high doses, its relatively good EPS tolerability at low to medium doses probably reflects the fact that its major metabolite, N-Desmethylperphenazine, which with chronic use attains blood levels 1.5-2 times those of the parent drug, shows modest M1 binding ∴ this might be a drug to start and hold low in order to allow build-up of the metabolite in the expectation of an anti-EPS effect as doses rise
  • - CATIE suggests comparable effectiveness with some atypical antipsychotics
Special Populations

Category C—Although occasionally published reports have linked various phenothiazine compounds with congenital defects, the bulk of the evidence suggests that the therapeutic use of these drugs is low risk for birth defects. However, according to the manufacturer, use of perphenazine in the 3rd trimester may cause extrapyramidal and/ or withdrawal symptoms in the newborn.

A 2009 review examined the potential teratogenic risk of antipsychotic drugs, including perphenazine, in pregnancy (7). No definitive association was found for an increased risk of birth defects or other adverse outcomes. However, the very limited data prevented concluding that these agents were safe in pregnancy.

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic function, concomitant disease or other drug therapy.

No dosage adjustment necessary.


No dosage adjustment necessary.

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Last updated July 08 2018 15:58:23. Disclaimer: This website does not provide medical advice, nor is it a substitute for clinical judgment.