Montelukast (mon-te-LOO-kast) is used for prevention and long-term treatment of asthma. It is also used to relieve allergy symptoms and exercise-induced bronchoconstriction (narrowing of the air passages in the lungs) in people who are not already taking this medicine for other conditions.
Montelukast is usually taken once daily in the evening for prevention of asthma or allergy symptoms. Swallow the regular tablet whole, with a glass of water. Montelukast may be taken with or without food. For exercise-induced bronchoconstriction, take a single dose at least 2 hours before you exercise, and do not take another dose for at least 24 hours. Follow your doctor's instructions. If you already take this medication to prevent asthma or allergy symptoms, do not use it for exercise-induced bronchoconstriction. Continue to use Montelukast even if you feel well. Do not miss any doses.
Check with your doctor if any of these most common side effects persist or become bothersome: cough, dizziness, headache, indigestion, nausea, stomach upset or pain; stuffy nose, tiredness, trouble sleeping, weakness.
Seek medical attention right away if any of these severe side effects occur: severe allergic reactions (rash, hives, difficulty breathing, tightness in the chest, swelling of the mouth, face, lips, or tongue); aggressive behavior, agitation, dark urine, fever, flu-like symptoms, hallucinations, irregular heartbeat, new or worsening wheezing or other breathing problems; numbness or tingling of hands or feet; seizures, severe or persistent stomach pain; severe sinus inflammation, swelling, unusual bruising or bleeding; upper respiratory tract infection, yellowing of the skin or eyes.
Symptoms of overdose may include hyperactivity, severe or persistent headache; stomach pain, unusual drowsiness or restlessness; unusual thirst, vomiting. If you suspect an overdose of Montelukast, seek medical attention immediately.
Montelukast may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Montelukast with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
Montelukast will not stop an asthma attack once one has started. Be sure you always carry appropriate medicine (eg, bronchodilator inhalers) with you in case of an asthma attack.
Contact your doctor promptly if your short-acting inhaler use increases or if use exceeds the 24-hour maximum prescribed by your doctor. Contact your doctor if your asthma worsens.
Do not decrease your dose or stop using Montelukast or other asthma medicines without first checking with your doctor.
If your asthma is sensitive to aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) (eg, ibuprofen), continue to avoid those medicines as directed by your doctor.
If you become pregnant, contact your doctor right away. You will need to discuss the benefits and risks of using Montelukast while you are pregnant. It is not known if Montelukast is found in breast milk. If you are or will be breast-feeding while you are using Montelukast, check with your doctor. Discuss any possible risks to your baby.
Tell your health care provider if you are taking any other medicines, especially any of the following:
Certain anticonvulsants (eg, phenobarbital) or Rifampin because they may decrease Montelukast's effectiveness.
If you miss a dose of Montelukast, take it as soon as possible. If it is almost time for your next dose, skip the missed dose. Go back to your regular dosing schedule.
Do not take 2 doses at once.
Store Montelukast at 77 degrees F (25 degrees C). Brief storage at temperatures between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Montelukast out of the reach of children and away from pets.