loxapine (Loxitane, Dibenzoazepine, Cloxazepin)
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Introduction
Tradename: Loxitane.
Indications
- symptomatic management of psychotic disorders
- may be preferred for paranoid patients
Contraindications
- narrow-angle glaucoma
- bone marrow depression
- severe liver disease
- severe cardiac disease
- severe CNS depression or coma
Dosage
- 12.5-50 mg IM every 4-6 hours, PRN.
- start 10 mg PO BID
- usual effective dose: 60-100 mg//day divided BID-QID
- max 250 mg/day
Tabs: 5, 10, 25, 50 mg.
Liquid: 25 mg/mL.
Pharmacokinetics
- metabolized by liver to many active metabolites
- metabolites excreted in the urine & feces
- elimination 1/2life is 4-5 hours
elimination via liver
elimination via kidney
Adverse effects
- common (> 10%)
- drowsiness
- extrapyramidal symptoms are moderate
- tardive dyskinesia (persistent)
- pseudoparkinsonism
- dystonias
- akathisia
- low anticholinergic & orthostatic hypotensive effects
- less common (1-10%)
- constipation, skin rash, breast enlargement, nausea/vomiting
- uncommon (< 1%)
- tachycardia, arrhythmias, abnormal T-waves with prolonged ventricular repolarization, sedation, restlessness, anxiety, altered central temperature regulation, hyperpigmentation, pruritus, rash, amenorrhea, galactorrhea, gynecomastia, weight gain, adynamic ileus, agranulocytosis*, leukopenia#, retinal pigmentation, urinary retention, overflow incontinence, sexual dysfunction, photosensitivity,
- other
- moderate sedation profile
- neuroleptic malignant syndrome is rare
- QT prolongation
- direct myocardial depression
- seizures (rare)
- increased mortality in elderly
* Most frequent in women in 4th-10th week of therapy
# Usually after large doses for prolonged periods
Drug interactions
(see chlorpromazine)
- drug interaction(s) of antipsychotics & dopamine receptor agonists
- drug interaction(s) of antipsycotics with benzodiazepines
Mechanism of action
- intermediate/high potency antipsychotic
- has antidepressant properties
- see chorpromazine
More general terms
Additional terms
References
- ↑ The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
- ↑ Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
- ↑ Kaiser Permanente Northern California Regional Drug Formulary, 1998
- ↑ Schneeweiss S et al, Risk of death with use of conventional versus atypical antipsychotic drugs among elderly patients. CMAJ 2007, 176:627 PMID: https://www.ncbi.nlm.nih.gov/pubmed/17325327