Cough Suppressants

Medication Information Leaflet

What are Cough Suppressants for?

Cough Suppressants are a group of cough medications which work by stopping the urge to cough and reducing the times you cough. Cough Suppressants may contain ingredients such as codeine, dextromethorphan, pholcodine, promethazine and diphenhydramine. They may be found in either liquid, tablet form, or lozenges form.

They can be found in combination with other ingredients for a runny or blocked nose.

How should I take/use Cough Suppressants?

  • Take Cough Suppressants as prescribed by your healthcare professional. Consult your healthcare professional if you are not sure how to take the cough medication correctly.
  • Cough Suppressants may be taken with or without food.
  • For Cough Suppressant syrups, shake the bottle well before use.
  • If your symptoms persist or worsen after one week of taking Cough Suppressants, please speak to your healthcare professional.

What should I do if I forget to take/use Cough Suppressants as prescribed?

If you forget to take a dose, take it as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and continue normally. Do not take two doses of the cough medication to make up for the missed dose.

What precautions should I take when taking Cough Suppressants?

Inform your healthcare professional if:
  • You are allergic to Cough Suppressants or any of the other ingredients of Cough Suppressants.
  • You are taking any long-term medications, including supplements, traditional medications and herbal remedies.
  • You have a history of asthma, lung diseases, difficulty urinating, seizures, high blood pressure, heart or liver diseases.
  • You are pregnant, planning to become pregnant or breastfeeding.

What are some common side effects of taking Cough Suppressants?

  • Some Cough Suppressants may cause drowsiness or dizziness.
    • Avoid driving, operating machinery or other activities which require concentration if affected.
  • Common side effects of Cough Suppressants may include nausea or vomiting, stomach upset and constipation.
    • These effects are usually mild and will pass quickly.

What are some rare but serious side effects of taking Cough Suppressants that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following:
  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body
Signs that your condition may require further medical attention include:
  • Cough with thick yellow or green phlegm or mucus, or blood
  • Fever more than 38.6°C
  • Unintended weight loss
  • Drenching night sweats
  • Cough lasting for longer than 3-4 weeks
  • Cough that happens after your start a new medication
  • Development of new symptoms during self-treatment
If you experience any of these symptoms, you should stop taking the Cough Suppressant and see your healthcare professional immediately.

What food or medication should I avoid when I take Cough Suppressants?

Do let your healthcare professional know if you are taking any other long-term medications, especially medications for mood disorders (e.g. Fluvoxamine), seizures (e.g. Phenytoin), runny nose (e.g. chlorpheniramine), muscle relaxants (e.g. Orphenadrine), sleeping pills (e.g. Lorazepam).

How should I store Cough Suppressants?

Store in a cool and dry place, away from direct sunlight. Keep Cough Suppressants away from children.

For cough syrups, discard the bottle 6 months after first opening or if expired, whichever sooner.

How should I dispose Cough Suppressants safely?

Pack Cough Suppressants into a black trash bag and seal it tightly before throwing it into the rubbish chute or bin.

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last reviewed on February 2020

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