Side effects when using theophylline include vomiting, central nervous system excitement, fever, rash and palpitations. Side effects usually subside with dosage adjustments and/or continued therapy. Theophylline should not be used in patients allergic to this class of medication. Do not use in pregnant or lactating animals.
Theophylline should be used with caution in patients with severe heart disease, liver or kidney disease, hyperthyroidism, hypertension or stomach ulcers.