Loxapine

From Anvita Health Wiki

Contents 1 Introduction 2 Indications 3 Contraindications 4 Dosage 5 Pharmacokinetics 6 Adverse-effects 7 Drug-interactions 8 Mechanism-of-action 9 More General Terms 10 Additional Terms 11 Internet Database 12 References

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
  

• pregnancy category = c
• safety in lactation = ?

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

• blurred vision, dry mouth, confusion

• 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, pruritis, 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 adverse effects of antipsychotic agents

Drug-interactions

• (see chlorpromazine)
  
• drug interaction(s) of antipsycotics with benzodiazepines

Mechanism-of-action

• intermediate/high potency antipsychotic
• has antidepressant properties
• see chorpromazine

More General Terms

• antipsychotic agent

Additional Terms

• chlorpromazine (Thorazine, Ormazine, Propaphenin, Sonazine, Chloractil)

Internet Database

PubChem: 3964
PubChem: 71399
PubChem: 71400

References

1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
2. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
3. Kaiser Permanente Northern California Regional Drug Formulary, 1998
4. Schneeweiss S et al, Risk of death with use of conventional versus atypical antipsychotic drugs among elderly patients. CMAJ 2007, 176:627 PMID: [1]

loxapine (Loxitane, Dibenzoazepine, Cloxazepin)