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zileuton (Zyflo, Zyflo CR)

Tradename: Zyflo, Zyflo CR Indications: - prophylaxis for exercise or aspirin-induced bronchial asthma Contraindications: - acute liver disease, serum ALT > 3X upper limit of normal Dosage: 600 mg PO QID Pharmacokinetics: - metabolized in the liver by cyt P450 1A2 & cyt P450 3A4 Monitor: - serum ALT baseline, monthly for the 1st 3 months, every 2-3 months for the remainder of the 1st year, then periodically [5] Adverse effects: 1) dyspepsia 2) nausea 3) myalgia 4) abdominal discomfort 5) increased serum alanine aminotransferase (serum ALT) 6) agitation, aggression, anxiousness, dream abnormalities & hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking & behavior (including suicide), & tremor [4] Drug interactions: 1) may potentiate effects of drugs metabolized by cyt P450 1A2 -> theophylline 2) any drug which inhibits cyt P450 1A2 or cyt P450 3A4 can increase zileuton levels 3) any drug which induces cyt P450 1A2 or cyt P450 3A4 can diminish zileuton levels Mechanism of action: 1) inhibits leukotriene synthesis, lipoxygenase inhibitor? 1) 5-lipoxygenase inhibitor 2) inhibits cyt P450 1A2 thus its own metabolism

Related

cytochrome p450 1A2 (cytochrome P3-450, phenacetin deethylase, cytochrome p450-4, CYP1A2) cytochrome P450 3A4 (cytochrome P450 C3, nifedipine oxidase, P450-PCN1, NF-25, CYP3A4)

General

heterocyclic compound, 2 rings lipoxygenase inhibitor

Properties

MISC-INFO: elimination route LIVER pregnancy-category C safety in lactation -

Database Correlations

PUBCHEM cid=60490

References

  1. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 742
  2. Prescriber's Letter 13(3): 2006 Cytochrome P450 drug interactions Detail-Document#: 220233 (subscription needed) http://www.prescribersletter.com
  3. Prescriber's Letter 14(9): 2007 Extended-release zileuton (Zyflo CR) and its role in asthma Detail-Document#: 230911 (subscription needed) http://www.prescribersletter.com
  4. Food and Drug Administraton (FDA MedWatch) Updated Information on Leukotriene Inhibitors: Montelukast (marketed as Singulair), Zafirlukast (marketed as Accolate), and Zileuton (marketed as Zyflo and Zyflo CR) 6/12/2009 http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/DrugSafetyInformationforHeathcareProfessionals/ucm165489.htm
  5. Prescriber's Letter 17(7): 2010 Recommended Lab Monitoring for Common Medications Liver Function Test Scheduling Detail-Document#: 260704 (subscription needed) http://www.prescribersletter.com

Substructures