Montelukast

Montelukast is a leukotriene receptor antagonist medicine available in Bangladesh under many brand names. Below are its uses, dosage, side effects and precautions — and all brands with their current prices.

• Long-term control and prevention of asthma (adults and children)
• Prevention of exercise-induced bronchospasm
• Seasonal and perennial allergic rhinitis
• Asthma with coexisting allergic rhinitis
• Aspirin-sensitive asthma (as advised by a doctor)

Montelukast is taken once daily, preferably in the evening for asthma, with or without food. Usual doses are 10 mg for adults and adolescents over 15 years, 5 mg (chewable) for children 6–14 years, and 4 mg (chewable or granules) for children 2–5 years — children's treatment must be directed by a doctor. For exercise-induced symptoms, a dose may be taken at least 2 hours before exercise, but not within 24 hours of a previous dose. Take it regularly every day, even when symptom-free, and never use Montelukast to treat an attack that has already started — keep a fast-acting reliever inhaler for that.

Montelukast is generally well tolerated. Common side effects include headache, stomach pain, diarrhoea, and mild upper respiratory symptoms; children may have thirst or hyperactivity. Importantly, montelukast can rarely cause mood and behaviour changes — agitation, irritability, bad dreams, sleep disturbance, anxiety, depression, and in rare cases suicidal thoughts. Watch for any change in mood or behaviour, especially in children, and report it to the doctor immediately; the medicine is usually stopped if this occurs. Very rarely, allergic reactions or flu-like illness with rash may appear.

Tell your doctor about any history of depression, anxiety, or other mental health conditions before starting montelukast, and monitor mood and behaviour during treatment — particularly in children. Do not reduce or stop your inhaled steroid or other asthma medicines on your own when montelukast is added; changes should be gradual and doctor-guided. Continue carrying your reliever inhaler at all times. Chewable tablets contain aspartame, which matters for patients with phenylketonuria. If asthma worsens despite regular use, see your doctor promptly.

Montelukast has few clinically important interactions. Enzyme-inducing drugs such as rifampicin, phenytoin, carbamazepine, and phenobarbital can lower montelukast levels and reduce its effect; gemfibrozil can raise its levels. No dose adjustment is generally needed with theophylline, oral contraceptives, warfarin, or digoxin, but always tell your doctor and pharmacist about every medicine, supplement, or herbal product you take so they can check for problems.

Montelukast must not be taken by anyone with known hypersensitivity to montelukast or any component of the product. It should not be used as monotherapy for an acute asthma attack or for status asthmaticus. Patients who developed serious neuropsychiatric symptoms on montelukast previously should generally not restart it. Chewable tablets are contraindicated in phenylketonuria due to their aspartame content.

Pregnancy: Available data have not shown major harm, but montelukast is used in pregnancy only when the doctor considers it clearly needed — usually in women whose asthma responded well to it before pregnancy. Lactation: Small amounts pass into breast milk; use while breastfeeding only on a doctor's advice, weighing benefit against risk. Never stop asthma treatment in pregnancy without consulting your doctor, as uncontrolled asthma harms both mother and baby.

Store below 30°C in a dry place, protected from light and moisture. Keep tablets in the original blister until use; granule sachets should be used within 15 minutes of opening. Keep out of the reach of children and do not use after the expiry date.