Prescription requiredAntiallergic (Anti-allergic/Anti-asthmatic)

Allegra M 120/10 Tablet — Side Effects & Warnings

Known side effects of Allegra M 120/10 Tablet include Headache, dizziness, drowsiness, fatigue, dry mouth, nausea, abdominal pain, diarrhoea, upper respiratory tract infection, sore throat. Not everyone experiences these side effects.

Medically reviewed by Dr. Balaji Krishnan, MBBS · Updated July 2026

Common Side Effects

Headache
dizziness
drowsiness
fatigue
dry mouth
nausea
abdominal pain
diarrhoea
upper respiratory tract infection
sore throat

This is not an exhaustive list. Consult your doctor if you notice any unusual symptoms.

Important Warnings

Schedule H medicine—use on doctor’s advice. Use with caution in kidney disease (fexofenadine exposure may increase) and in elderly. Avoid driving/operating machinery if you feel dizzy or sleepy. Montelukast has been associated with neuropsychiatric events (e.g., agitation, anxiety, sleep disturbances, depression, suicidal thoughts); stop and seek medical help if mood/behaviour changes occur. Not for acute asthma attack relief. Inform doctor about all medicines and allergies.

Drug Interactions

Allegra M 120/10 Tablet may interact with the following:

Antacids containing aluminium or magnesium (reduce fexofenadine absorption)
fruit juices (reduce fexofenadine absorption)
erythromycin/ketoconazole (may increase fexofenadine levels)
rifampicin and enzyme inducers (may reduce montelukast levels)
other sedatives/alcohol (may increase dizziness/somnolence)

Always tell your doctor about all medicines you are taking, including over-the-counter drugs and supplements.

Pregnancy Safety

Consult doctor

Alcohol Interaction

Use with caution

Habit Forming

Storage

Store below 25°C in a dry place, protected from light and moisture. Keep out of reach of children.

Allegra M 120/10 Tablet — Safety Summary

Composition: Montelukast (10mg) + Fexofenadine (120mg)
Prescription: Required (Rx)
Pregnancy: Consult doctor
Alcohol: Use with caution
Habit forming: No

Allegra M 120/10 Tablet — Safety FAQs

What should I do if I experience side effects?

Mild side effects often resolve on their own. If side effects are severe or persistent, stop the medicine and consult your doctor immediately.

Are all listed side effects common?

No. Some side effects are common while others are rare. Not everyone experiences side effects. Consult your doctor if you are concerned.

Can I take this medicine with other drugs?

Some medicines interact with each other. Always inform your doctor about all medicines you are currently taking.

When should I seek emergency help?

Seek immediate medical attention if you experience severe allergic reactions (difficulty breathing, swelling of face/throat), chest pain, or any life-threatening symptoms.

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Safety disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice. If you experience severe side effects, seek medical attention immediately.

Allegra M 120/10 Tablet — Side Effects & Warnings

Medically reviewed by Dr. Balaji Krishnan, MBBS · Updated July 2026