Acetophenazine
Pronunciation
(a set oh FEN a zeen)
Synonyms
Acetophenazine Maleate
Generic Available
No
Use
Management of manifestations of psychotic disorders
Restrictions
Not available in U.S.
Pregnancy Risk Factor
C
Contraindications
Hypersensitivity to acetophenazine or any component of the formulation; blood dyscrasias and bone marrow suppression; patients in coma or brain damage
Adverse Reactions
>10%:
Cardiovascular: Hypotension, orthostatic hypotension
Central nervous system: Pseudoparkinsonism, akathisia, dystonias, tardive dyskinesia, dizziness
Gastrointestinal: Constipation
Ocular: Pigmentary retinopathy
Respiratory: Nasal congestion
Miscellaneous: Diaphoresis (decreased)
1% to 10%:
Dermatologic: Increased sensitivity to sun, rash
Endocrine & metabolic: Changes in menstrual cycle, breast pain, libido (changes in)
Gastrointestinal: Weight gain, nausea, vomiting, stomach pain
Genitourinary: Difficulty in urination, ejaculatory disturbances
Neuromuscular & skeletal: Trembling fingers
<1%: Agranulocytosis, cholestatic jaundice, cornea and lens changes, discoloration of skin (blue-gray), galactorrhea, hepatotoxicity, impairment of temperature regulation, leukopenia, lowering of seizure threshold, neuroleptic malignant syndrome (NMS), pigmentary retinopathy, priapism
Drug Interactions
Aluminum salts: May decrease the absorption of phenothiazines; monitor
Amphetamines: Efficacy may be diminished by antipsychotics. In addition, amphetamines may increase psychotic symptoms; avoid concurrent use.
Anticholinergics: May inhibit the therapeutic response to phenothiazines and excess anticholinergic effects may occur; includes benztropine, trihexyphenidyl, biperiden, and drugs with significant anticholinergic activity (TCAs, antihistamines, disopyramide)
Antihypertensives: Concurrent use of phenothiazines with an antihypertensive may produce additive hypotensive effects (particularly orthostasis)
Bromocriptine: Phenothiazines inhibit the ability of bromocriptine to lower serum prolactin concentrations
CNS depressants: Sedative effects may be additive with phenothiazines; monitor for increased effect; includes barbiturates, benzodiazepines, narcotic analgesics, ethanol, and other sedative agents
Epinephrine: Chlorpromazine (and possibly other low potency antipsychotics) may diminish the pressor effects of epinephrine
Guanethidine and guanadrel: Antihypertensive effects may be inhibited by chlorpromazine
Levodopa: Chlorpromazine may inhibit the antiparkinsonian effect of levodopa; avoid this combination
Lithium: Chlorpromazine may produce neurotoxicity with lithium; this is a rare effect
Metoclopramide: May increase extrapyramidal symptoms (EPS) or risk.
Phenytoin: May reduce serum levels of phenothiazines; phenothiazines may increase phenytoin serum levels
Propranolol: Serum concentrations of phenothiazines may be increased; propranolol also increases phenothiazine concentrations
Polypeptide antibiotics: Rare cases of respiratory paralysis have been reported with concurrent use of phenothiazines
QTc-prolonging agents: Effects on QTc interval may be additive with phenothiazines, increasing the risk of malignant arrhythmias; includes type Ia antiarrhythmics, TCAs, and some quinolone antibiotics (sparfloxacin, moxifloxacin and gatifloxacin)
Sulfadoxine-pyrimethamine: May increase phenothiazine concentrations
Tricyclic antidepressants: Concurrent use may produce increased toxicity or altered therapeutic response
Trazodone: Phenothiazines and trazodone may produce additive hypotensive effects
Valproic acid: Serum levels may be increased by phenothiazines
Ethanol/Nutrition/Herb Interactions
Ethanol: Avoid ethanol (may increased sedation)
Stability
Protect from light; dispense in amber or opaque vials
Mechanism of Action
Acetophenazine is a piperazine phenothiazine antipsychotic which antagonizes the effects of dopamine in the basal ganglia and limbic areas of the forebrain; this activity appears responsible for the antipsychotic efficacy, as well as the production of extrapyramidal symptoms; increases the secretion of prolactin and has a marked suppressive effect on the chemoreceptor trigger zone; also produces peripheral blockade of cholinergic neurons
Pharmacodynamics/Kinetics
Onset of action: 2-4 hours
Duration: ~24 hours
Absorption: Tissue saturation, particularly in high lipid tissues (eg, CNS)
Half-life elimination: 20-40 hours
Dosage
Adults: Oral: 20 mg 3 times/day up to 60-120 mg/day
Hospitalized schizophrenic patients may require doses as high as 400-600 mg/day
Hemodialysis: Not dialyzable (0% to 5%)
Monitoring Parameters
Vital signs; lipid profile, fasting blood glucose/Hgb A1c; BMI; mental status, abnormal involuntary movement scale (AIMS), extrapyramidal symptoms (EPS)
Patient Education
Do not take antacid within 1 hour of taking drug; may cause drowsiness, avoid alcohol; avoid excess sun exposure (use sunblock); rise slowly from recumbent position; use of supportive stockings may help prevent orthostatic hypotension
Nursing Implications
Observe for tremor and abnormal movement or posturing (extrapyramidal symptoms), increased confusion or psychotic behavior, constipation, urinary retention, abnormal gait
Additional Information
Not available in U.S.
Dental Health: Effects on Dental Treatment
No significant effects or complications reported
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Dosage Forms
Tablet, as maleate: 20 mg
References
Peabody CA, Warner MD, Whiteford HA, et al, "Neuroleptics and the Elderly,"
J Am Geriatr Soc
, 1987, 35(3):233-8.
Risse SC and Barnes R, "Pharmacologic Treatment of Agitation Associated With Dementia,"
J Am Geriatr Soc
, 1986, 34(5):368-76.
Saltz BL, Woerner MG, Kane JM, et al, "Prospective Study of Tardive Dyskinesia Incidence in the Elderly,"
JAMA
, 1991, 266(17):2402-6.
Seifert RD, "Therapeutic Drug Monitoring: Psychotropic Drugs,"
J Pharm Pract
, 1984, 6:403-16.
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