Theophylline opens the airways in your lungs, making it easier to breathe. It works by relaxing the smooth muscles around your airways that can tighten in asthma, COPD, and other lung conditions.
If you forget to take a dose, take it as soon as you remember. If it is too close to the next dose, skip the dose and take the next dose at the usual time. Do not take two doses together to make up for the missed dose.
Inform your healthcare professional if:
Some medications may interact with theophylline and affect the levels of theophylline in your body. Check with your healthcare professional to see if any of your medications interact with theophylline.
You should cut down on your intake of caffeine as it has similar effects to theophylline. Caffeine is commonly found in tea, coffee, chocolates, and cola.
Inform your doctor if you smoke or plan to quit smoking, as this can affect how your body processes theophylline.
The common side effects include:
These symptoms may occur but should get better over time. Check with your doctor if any of these symptoms worsens or do not go away.
The symptoms of a drug allergy include one or more of the following:
You can also find out about drug allergies by watching these videos:
For videos in 中文, Melayu and தமிழ், click here.
Other serious side effects include:
If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.
Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.
Pack this medication into a black trash bag and seal it tightly before throwing 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 (NHG Health, 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 2026
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