Zafirlukast Side Effects

Some side effects of zafirlukast may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

For the Consumer

Applies to zafirlukast: oral tablet

Get emergency medical help if you have any of these signs of an allergic reaction while taking zafirlukast: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

• worsening asthma symptoms;

• new or worsening cough, fever, trouble breathing;

• mood or behavior changes, anxiety, depression, sleep problems (insomnia);

• skin rash, bruising, severe tingling, numbness, pain, muscle weakness; or

• nausea, pain in your upper stomach, loss of appetite, flu symptoms, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects of zafirlukast may include:

• headache;

• diarrhea, stomach pain;

• weakness;

• dizziness;

• muscle pain; or

• sore throat, cold symptoms.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For Healthcare Professionals

Applies to zafirlukast: oral tablet

Nervous system

Nervous system side effects have included headache, asthenia, somnolence, dizziness, fever, insomnia, and pain.

Immunologic

A 47-year-old man with persistent asthma developed sinus congestion, cough, malaise, arthralgia, a progressive rash over his trunk and extremities, and fever within one month of reinitiating zafirlukast therapy. Prior to the development of these symptoms, the patient had been receiving inhaled steroids in combination with zafirlukast therapy. A skin eruption was observed on his face, arms, and trunk. A chest film showed basilar reticulonodular infiltrates, and laboratory findings revealed a positive titer for rheumatoid factor, a blood eosinophil count of 4,350 and an elevated total IgE level (851 intl units/L). The patient's prior medications were discontinued, and he was treated with intravenous hydrocortisone, acyclovir, ceftriaxone, and erythromycin. The patient demonstrated rapid improvement of all signs and symptoms following initiation of hydrocortisone. A causal relationship between zafirlukast therapy and the development of systemic vasculitis was suspected.

Following nearly two months of zafirlukast therapy, a 53-year-old female with a history of asthma and chronic sinusitis developed arthralgias involving her knees, wrists, shoulder and joints. She further developed amaurosis fugax and a hemorrhagic, maculopapular eruption on her elbows and fingers. Her chest film showed multiple pulmonary nodes, and a bronchoscopic lung biopsy revealed eosinophilic infiltrates and granulomas. The patient was initiated on high-dose steroid therapy after which all signs and symptoms promptly resolved. It was believed that this case report represented zafirlukast-induced Churg-Strauss syndrome independent of steroid therapy.

Immunologic side effects have included Churg-Strauss syndrome, also known as allergic granulomatosis, and drug-induced lupus. In addition, increased incidence of infection in patients over the age of 55 has been noted in clinical trials of patients receiving zafirlukast.

Gastrointestinal

Gastrointestinal side effects have included dry mouth, nausea, diarrhea, abdominal pain, vomiting and dyspepsia.

Musculoskeletal

Musculoskeletal side effects have included arthralgia, myalgia and back pain.

Hepatic

In clinical trials, SGPT elevations were comparable between treatment and placebo groups. However, one case of hepatitis and hyperbilirubinemia was observed in a patient receiving zafirlukast 40 mg per day for 100 days.

Hepatic side effects have included elevations of hepatic transaminase levels.

General

General side effects have included malaise.

Dermatologic

Dermatologic side effects have included pruritus.

Psychiatric

Psychiatric side effects have included insomnia and depression.

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