Montelukast

• Adults and children 15 years and older: 10 mg once a day.
• Children 6–14 years old: 5 mg once a day.
• Children 2–5 years old: 4 mg once a day.
• Always take your montelukast exactly as your doctor has told you.
• The pharmacy label on your medicine will tell you how much montelukast to take, how often to take it and any special instructions.

• Timing: It is best to take montelukast in the evening. Take your tablet at the same time each day to help you remember. 
  • Tablets 10 mg: Swallow your tablet with a drink of water. You can take it before or after food.  
  • Chewable tablets (4 mg and 5 mg): Chew the tablet before swallowing. It is best to take the chewable tablet on an empty stomach, eg, 1 hour before food or 2 hours after food. Food can interfere with the absorption of this medicine.  
• Missed dose: If you forget to take your dose, take it as soon as you remember that day. But if it is nearly time for your next dose, take the next dose at the right time. Do not take double the dose.

• Are you pregnant or breastfeeding?

If so, it’s important that you tell your doctor or pharmacist before you start montelukast. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Like all medicines, montelukast can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Changes in behaviour or mood

Montelukast can cause changes in behaviour or mood including sleep problems, strange dreams, hallucinations, feeling anxious or agitated, irritability, restlessness, tremor, low mood, depression and suicidal thoughts.

Tell your doctor immediately or phone Healthline on 0800 611 116 if you or your child gets these side effects.