Medication Information Leaflet

What are these medications for?

Cough suppressants are a group of medications which work by stopping the urge to cough and reducing cough. Cough suppressants may contain ingredients such as codeine, dextromethorphan, promethazine and diphenhydramine. They may be found as either liquids, tablets, capsules or lozenges.

They may also be found in combination with other ingredients for relief of runny or blocked nose. 

How should I take or use these medications?

• Take these medications as recommended by your healthcare professional. Consult your healthcare professional if you are not sure how to take these medications correctly.
• These medications may be taken with or without food
• For syrups, shake the bottle well before use.
• If your symptoms do not go away or worsen after one week of taking these medications, please speak to your healthcare professional.

What should I do if I forget to take or use these medications?

Cough suppressants may be taken when required for a short period of time. This means that you do not have to take them if you do not have any symptoms. If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and continue normally. Do not take two doses or extra medication to make up for the missed dose.

What precautions should I take when taking or using these medications?

Inform your healthcare professional if:

• You are allergic to cough suppressants, or any other ingredients used in these medications.
• You are taking any other medications, including supplements, traditional medications and herbal remedies.
• You have a history of glaucoma (a group of eye conditions where an increase in fluid pressure inside the eye may lead to vision loss due to damage of the optic nerve), asthma, lung diseases, gastroesophageal reflux disease (a condition where stomach contents flow back to the throat), difficulty urinating, seizures, high blood pressure, heart or liver diseases.
• You are pregnant, planning to become pregnant or breastfeeding.
• You are a smoker or have recently taken steps to quit smoking.

What are some common side effects of these medications?

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

What are some rare but serious side effects 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
• Cough with bloody or pink frothy phlegm or mucus
• Fever more than 38.6^oC
• Wheezing or shortness of breath
• Chest pain
• Swelling at the legs or ankles
• Unintended weight loss
• Drenching night sweats
• Cough lasting for longer than three to four weeks
• Cough that happens after starting a new medication
• Having new symptoms during self-treatment

If you experience any of these symptoms, you should stop these medications and see your doctor immediately.

What food or medication should I avoid when I take or use these medications?

Let your healthcare professional know if you are taking or planning to take any of the following:

• Medications for mood disorders (e.g. Fluvoxamine)
• Medications for seizures (e.g. Phenytoin)
• Medications for runny nose (e.g. Chlorpheniramine)
• Muscle relaxants (e.g. Orphenadrine)
• Sleeping pills (e.g. Lorazepam)

How should I store these medications?

Store in a cool and dry place away from direct sunlight. Keep these medications away from children.

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

How do I throw away these medications safely?

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

Disclaimers

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 updated on June 2024.