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zafirlukast (za-feer-loo-kast)



Therapeutic: antiasthmatics, bronchodilators

Pharmacologic: leukotriene antagonists


Long-term control agent in the management of asthma.


Antagonizes the effects of leukotrienes, which are components of slow-reacting substance of anaphylaxis (SRSA). These substances mediate the following: Airway edema, Smooth muscle constriction, Altered cellular activity. Result is decreased inflammatory process that is part of asthma. Therapeutic Effects: ↓ frequency and severity of asthma.

Adverse Reactions/Side Effects

CNS: headache, dizziness, weakness. GI: HEPATOTOXICITY, abdominal pain, diarrhea, dyspepsia, nausea, vomiting. MS: arthralgia, back pain, myalgia. Misc: CHURG-STRAUSS SYNDROME, fever, infection (geriatric patients).


Examination and Evaluation

  • Be alert for signs of eosinophilic conditions and allergic blood vessel reactions, including Churg-Strauss syndrome. Early signs include allergic rhinitis, sinusitis, asthma, or hay fever–like reactions. Symptoms can increase to include fever, skin rash, joint pain, severe pain and numbness (peripheral neuropathy), shortness of breath, coughing up blood, bloody urine, chest pain, arrhythmias, and GI problems (diarrhea, nausea, vomiting, GI bleeding). Notify physician immediately for further evaluation of any signs listed above.

  • Watch for signs of hepatotoxicity, including anorexia, abdominal pain, severe nausea and vomiting, yellow skin or eyes, fever, sore throat, malaise, weakness, facial edema, lethargy, and unusual bleeding or bruising. Report these signs to the physician immediately.

  • Assess pulmonary function at rest and during exercise (See Appendices I, J, K) to document effectiveness of medication in controlling bronchocon-striction and asthma attacks.

  • Assess any back, joint, or muscle pain to rule out musculoskeletal pathology; that is, try to determine if pain is drug induced rather than caused by anatomic or biomechanical problems.

  • Assess dizziness and weakness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.


  • When implementing airway clearance techniques or respiratory muscle training, attempt to intervene when the airway is maximally bronchodilated. Patients should experience optimal effects after one week of recommended daily administration.

Patient/Client-Related Instruction

  • Advise patient not to exceed the recommended dose or frequency of administration. Contact physician if bronchospasm is not adequately controlled by the current medication regimen, or if respiratory symptoms continue to worsen.

  • Instruct patient and family/caregivers to report other troublesome side effects, including severe or prolonged headache, fever, infections, or GI problems (nausea, vomiting, diarrhea, indigestion, abdominal pain).


Absorption: Rapidly absorbed after oral administration.

Distribution: Enters breast milk.

Protein Binding: 99%.

Metabolism and Excretion: Mostly metabolized by the liver; 10% ...

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