Dextromethorphan

Cough suppressant
ALSO SOLD WITHOUT PRESCRIPTION

Dextromethorphan is a cough suppressant found in 2 medicines sold in India, such as Corex DX, Alex Syrup. Below: what it is for, how it works, how to take it, side effects, interactions and pregnancy advice.

Also called: dxm

What it is used for

Calms a dry, tickly cough.

How it works

A cough suppressant that acts on the cough centre of the brain. It is meant for a dry, tickly cough.

How to take it

Adults usually take 10 to 20 mg every 4 hours or 30 mg every 6 to 8 hours; no more than 120 mg a day. Not for children under 6 unless advised.

Common side effects

  • Drowsiness
  • Dizziness
  • Nausea
  • Constipation

Get medical help straight away if

  • Agitation, confusion, fever, shivering or muscle twitching (serotonin syndrome)
  • Hallucinations (sign of misuse or overdose)

Be careful

Not for chesty cough with phlegm; misuse in high doses is dangerous.

Other medicines and interactions

Do not combine with MAOI antidepressants. Risk of serotonin syndrome with SSRIs, SNRIs and tramadol. More drowsiness with alcohol and sedatives.

Pregnancy and breastfeeding

Short use is generally considered acceptable in pregnancy and breastfeeding, but ask a pharmacist first; avoid combination products with many ingredients.

Combination medicines that contain Dextromethorphan (2)

Alex SyrupCorex DX

Common questions

What is Dextromethorphan used for?

Calms a dry, tickly cough.

How does Dextromethorphan work?

A cough suppressant that acts on the cough centre of the brain. It is meant for a dry, tickly cough.

How should I take Dextromethorphan?

Adults usually take 10 to 20 mg every 4 hours or 30 mg every 6 to 8 hours; no more than 120 mg a day. Not for children under 6 unless advised.

What are the side effects of Dextromethorphan?

Common: Drowsiness, dizziness, nausea, constipation. Get help straight away for: Agitation, confusion, fever, shivering or muscle twitching (serotonin syndrome), hallucinations (sign of misuse or overdose).

Does Dextromethorphan interact with other medicines?

Do not combine with MAOI antidepressants. Risk of serotonin syndrome with SSRIs, SNRIs and tramadol. More drowsiness with alcohol and sedatives.

Is Dextromethorphan safe in pregnancy and breastfeeding?

Short use is generally considered acceptable in pregnancy and breastfeeding, but ask a pharmacist first; avoid combination products with many ingredients.

Does Dextromethorphan need a prescription in India?

It is usually sold without a prescription in India, but ask a pharmacist if you take other medicines or have a long-term illness.

Which brands contain Dextromethorphan?

Alex Syrup, Corex DX.

Sources and further reading

NHS (UK National Health Service) and MedlinePlus (US National Library of Medicine) are free, reviewed medicine guides. Brand names and doses there may differ from India.

Last reviewed 31 October 2026. Written by Satya Babu from standard prescribing information.

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For information only, not medical advice. This page is a plain-language summary written from standard prescribing information and the public guides linked below. Brands sometimes change their formula, so always check the composition printed on the pack. Doses here are typical adult doses; yours may differ. Do not start, stop or change a medicine without your doctor or pharmacist, and keep all medicines away from children. In an emergency, call 112 (India) or your local emergency number.