Before using theophylline, tell your doctor or pharmacist if you are allergic to it; or to other xanthine drugs (such as aminophylline, oxtriphylline, caffeine); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: stomach/intestinal ulcer, seizures, thyroid disease, heart problems (such as heart failure, irregular heartbeat), liver disease, high blood pressure.

If you get sick or have a fever while taking this medication, tell your doctor right away. The dose of your medicine may need to be adjusted.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this drug, especially fast/irregular heartbeat, or trouble sleeping. Careful monitoring of side effects and drug blood levels is recommended.

Children may be more sensitive to the side effects of this drug. Careful monitoring of side effects and drug blood levels is recommended.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. Changes in your body during the last 3 months of pregnancy may affect the amount of this drug in your blood. Your doctor should carefully monitor the amount of drug in your blood, as well as any side effects, so that your dose may be changed if needed.

This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.