Pimozide

From Anvita Health Wiki

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

Introduction

• Tradename: Orap.

Indications

• suppression of severe motor tics & phonic tics in patients with Tourette's syndrome

Contraindications

• simple tics, not due to Tourette's syndrome
• history of cardiac dysrhythmias
• CNS depression
• blood dyscrasias
• depressive disorders
• parkinsonism

• Caution:

• treatment imposes serious risks to patient
• benefits must outweigh risks
  

• pregnancy category = c
• safety in lactation = -

Dosage

• start 1-2 mg PO QD
• most patients respond to 10 mg/day
• maximum: 20 mg/day

• Tabs: 2 mg.
• Reduction of dose for hepatic insufficiency

Pharmacokinetics

• oral absorption is 40-50%
• protein-binding is 99%
• metabolized in the liver by cyt P450 3A4

• significant 1st pass metabolism in liver

• elimination 1/2life of 55 hours
• time to peak serum concentration: within 6-8 hours
• metabolites excreted in the urine
  

• elimination via liver
• protein binding = 99 %

Adverse-effects

• common (> 10%)

• akathisia, akinesia, extrapyramidal effects, tachycardia, orthostatic hypotension, constipation, drowsiness dry mouth, rash, breast swelling

• less common (1-10%)

• tardive dyskinesia, diarrhea, anorexia, depression, swelling of the face

• uncommon (< 1%)

• jaundice, blood dyscrasias, neuroleptic malignant syndrome

• other

• tumorogenic in animal studies
• altered mental status
• autonomic instability
• lowers seizure threshold
  
• drug adverse effects of antipsychotic agents

Drug-interactions

• increased effect & toxicity of:

• alfentanil, CNS depressants, guanabenz, MAO inhibitors, agents which prolong the QT interval

• may exacerbate adverse effects of anticholinergic agents
• any drug that inhibits cyt P450 3A4 may increase levels of pimozide
• any drug that induces cyt P450 3A4 may diminish levels of pimozide
  
• drug interaction(s) of antipsycotics with benzodiazepines
• drug interaction(s) of citalopram with pimozide

More General Terms

• benzimidazole
• antipsychotic agent

Additional Terms

• cytochrome P450 3A4 (cytochrome P450 C3, nifedipine oxidase, P450-PCN1, NF-25, CYP3A4)
• Gilles de la Tourette's syndrome

Internet Database

PubChem: 16362
PubChem: 4824

References

1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
2. Kaiser Permanente Northern California Regional Drug Formulary, 1998
3. Department of Veterans Affairs, VA National Formulary

pimozide (Orap)