Montelukast

INTRODUCTION

Indications

Prevention and chronic treatment of asthma. Management of seasonal allergic rhinitis. Prevention of exercise-induced bronchoconstriction in patients 15 yr and older.

Action

Antagonizes the effects of leukotrienes, which mediate the following: Airway edema, Smooth muscle constriction, Altered cellular activity. Result is decreased inflammatory process, which is part of asthma and allergic rhinitis. Therapeutic Effects: Decreased frequency and severity of acute asthma attacks. Decreased severity of allergic rhinitis. Decreased attacks of exercise-induced bronchoconstriction.

Adverse Reactions/Side Effects

CNS: anxiety, depression, fatigue, headache, suicidal thoughts/behaviors, weakness. EENT: otitis (children), sinusitis (children). Resp: cough, rhinorrhea. GI: abdominal pain, diarrhea (children), dyspepsia, nausea (children), increased liver enzymes. Neuro: tremor. Derm: rash. Misc: EOSINOPHILIC CONDITIONS (INCLUDING CHURG-STRAUSS SYNDROME), fever.

PHYSICAL THERAPY IMPLICATIONS

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.

• Assess pulmonary function at rest and during exercise (See Appendices I, J, K) to determine effectiveness of medication in controlling bronchoconstriction.

• Monitor and report any changes in mood or behavior, including anxiety, depression, and suicidal thoughts.

• Monitor any muscle weakness or tremor. Report any neuromuscular problems that affect gait or other functional activities.

Interventions

• When implementing airway clearance techniques or respiratory muscle training, attempt to intervene when the airway is maximally bronchodilated. Peak responses typically occur 2–4 hr after oral 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, cough, ear pain, sinus inflammation, nasal discharge, skin rash, or GI problems (nausea, diarrhea, indigestion, abdominal pain).

Pharmacokinetics

Absorption: Rapidly absorbed (63–73%) following oral administration.

Distribution: Unknown.

Protein Binding: 99%.

Metabolism and Excretion: Mostly metabolized by the liver (by P4503A4 and 2C9 enzyme systems); metabolites eliminated in feces via bile; negligible renal excretion.

Half-life: 2.7–5.5 hr.