NZ Formulary



What does it do?

Theophylline opens narrowed airways in the lungs and helps to make breathing easier.

How should you take it?

Take theophylline regularly as directed, with food and a glass of water.
The tablets may be halved, but do not crush or chew them.
Measure the liquid carefully with an oral syringe or measuring spoon.

What if you forget a dose?

Take the missed dose as soon as possible. If it is close to the time for your next dose, skip the missed dose and carry on as normal. Do not take two doses at the same time.

Can you take other medicines?

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products (e.g. St John's wort) or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Fast or irregular heartbeat

Tell your doctor

Nervousness, tremor, trouble sleeping


Nausea, vomiting

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have heart, liver or thyroid problems, or if you have ever had a seizure.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Smoking (e.g. cigarettes or marijuana), large amounts of barbequed foods or caffeine-containing foods and drinks (e.g. coffee, tea, chocolate, cocoa, cola, Red Bull® or V®) may change the effect of theophylline.