Indications for: ACCOLATE

Prophylaxis and chronic treatment of asthma.

Adults and Children:

<5yrs: not established. Take 1hr before or 2hrs after meals. 5–11yrs: 10mg twice daily. ≥12yrs: 20mg twice daily.

ACCOLATE Contraindications:

Hepatic impairment including hepatic cirrhosis. 

ACCOLATE Warnings/Precautions:

Not for primary treatment of acute attack. Discontinue if clinical symptoms of liver dysfunction occur; do not resume if confirmed by lab results. Caution when withdrawing from oral steroids. Elderly. Pregnancy (Cat.B). Nursing mothers: not recommended.

ACCOLATE Classification:

Leukotriene receptor antagonist.

ACCOLATE Interactions:

Potentiates warfarin (monitor PT and adjust warfarin dose). Caution with drugs metabolized by CYP2C9 (eg, tolbutamide, phenytoin, carbamazepine) or CYP3A4 (eg, dihydropyridine calcium channel blockers, cyclosporine, cisapride). Zafirlukast plasma levels reduced by erythromycin, theophylline. Zafirlukast plasma levels increased by aspirin. May increase theophylline levels.

Adverse Reactions:

Headache, infection, GI upset, pain, fever; neuropsychiatric events (eg, insomnia, depression); rarely, hepatic dysfunction (esp. in females), agranulocytosis.


Zafirlukast is extensively metabolized. The most common metabolic products are hydroxylated metabolites which are excreted in the feces. In vitro studies using human liver microsomes showed that the hydroxylated metabolites of zafirlukast excreted in the feces are formed through the cytochrome P450 2C9 (CYP2C9) pathway. Additional in vitro studies utilizing human liver microsomes show that zafirlukast inhibits the cytochrome P450 CYP3A4 and CYP2C9 isoenzymes at concentrations close to the clinically achieved total plasma concentrations.

Drug Elimination:

Following oral administration of radiolabeled zafirlukast, urinary excretion accounts for approximately 10% of the dose and the remainder is excreted in feces.

In a bioequivalence study, the mean terminal half-life of zafirlukast is approximately 10 hours in both normal adult patients and patients with asthma. In other studies, the mean plasma half-life of zafirlukast ranged from approximately 8 to 16 hours in both normal patients and patients with asthma.

Generic Drug Availability:


How Supplied: