Complete adverse effect profile including incidence rates and management
Important Safety Information
This is not a complete list of all possible side effects. Contact your healthcare provider if you experience any unexpected symptoms. For serious or life-threatening side effects, seek emergency medical attention immediately.
ADVERSE REACTIONS Adults and Children 12 years of age and older The safety database for zafirlukast consists of more than 4,000 healthy volunteers and patients who received zafirlukast, of which 1,723 were asthmatics enrolled in trials of 13 weeks duration or longer.
A total of 671 patients received zafirlukast for 1 year or longer.
The majority of the patients were 18 years of age or older;
however, 222 patients between the age of 12 and 18 years received zafirlukast.
A comparison of adverse events reported by ≥1% of zafirlukast-treated patients, and at rates numerically greater than in placebo-treated patients, is shown for all trials in the table below.
Adverse Event Zafirlukast N=4,058 PLACEBO N=2,032 Headache 12.9% 11.7% Infection 3.5% 3.4% Nausea 3.1% 2.0% Diarrhea 2.8% 2.1% Pain (generalized) 1.9% 1.7% Asthenia 1.8% 1.6% Abdominal Pain 1.8% 1.1% Accidental Injury 1.6% 1.5% Dizziness 1.6% 1.5% Myalgia 1.6% 1.5% Fever 1.6% 1.1% Back Pain 1.5% 1.2% Vomiting 1.5% 1.1% SGPT Elevation 1.5% 1.1% Dyspepsia 1.3% 1.2% The frequency of less common adverse events was comparable between zafirlukast and placebo.
Rarely, elevations of one or more liver enzymes have occurred in patients receiving Zafirlukast in controlled clinical trials.
In clinical trials, most of these have been observed at doses four times higher than the recommended dose.
The following hepatic events (which have occurred predominantly in females) have been reported from postmarketing adverse event surveillance of patients who have received the recommended dose of zafirlukast (40 mg/day): cases of symptomatic hepatitis (with or without hyperbilirubinemia) without other attributable cause;
and rarely, hyperbilirubinemia without other elevated liver function tests.
WARNINGS Hepatotoxicity Cases of life-threatening hepatic failure have been reported in patients treated with zafirlukast.
Cases of liver injury without other attributable cause have been reported from post-marketing adverse event surveillance of patients who have received the recommended dose of zafirlukast (40 mg/day).
In most, but not all post-marketing reports, the patient’s symptoms abated and the liver enzymes returned to normal or near normal after stopping zafirlukast.
In rare cases, patients have either presented with fulminant hepatitis or progressed to hepatic failure, liver transplantation and death.
In extremely rare post-marketing cases, no clinical symptoms or signs suggestive of liver dysfunction were reported to precede the latter observations.
Like all medications, Zafirlukast can cause side effects. However, not everyone who takes this medication will experience them. Many side effects are dose-dependent and may improve as your body adjusts to the medication. Others may require dose adjustment or medical attention.
Contact your healthcare provider promptly if you experience:
Seek immediate emergency medical care if you experience signs of: