(DYE fi lin)

U.S. Brand Names

Dilor®; Lufyllin®


Dihydroxypropyl Theophylline

Generic Available


Canadian Brand Names

Dilor®; Lufyllin®


Bronchodilator in reversible airway obstruction due to asthma or COPD

Pregnancy Risk Factor



Uncontrolled arrhythmias; hyperthyroidism

Adverse Reactions

Uncommon at serum theophylline concentrations 20 mcg/mL

1% to 10%:

Cardiovascular: Tachycardia

Central nervous system: Nervousness, restlessness

Gastrointestinal: Nausea, vomiting

Drug Interactions

Dyphylline may decrease the effects of phenytoin, lithium, and neuromuscular blocking agents. Dyphylline may have synergistic toxicity with sympathomimetics. Cimetidine, ranitidine, allopurinol, beta-blockers (nonspecific), erythromycin, influenza virus vaccine, corticosteroids, ephedrine, quinolones, thyroid hormones, oral contraceptives, amiodarone, troleandomycin, clindamycin, carbamazepine, isoniazid, loop diuretics, and lincomycin may increase dyphylline concentrations. Cigarette and marijuana smoking, rifampin, barbiturates, hydantoins, ketoconazole, sulfinpyrazone, sympathomimetics, isoniazid, loop diuretics, carbamazepine, and aminoglutethimide may decrease dyphylline concentrations. Tetracyclines enhance toxicity and benzodiazepine's action may be antagonized.


Children: I.M.: 4.4-6.6 mg/kg/day in divided doses


Oral: Up to 15 mg/kg 4 times/day, individualize dosage

I.M.: 250-500 mg, do not exceed total dosage of 15 mg/kg every 6 hours

Dosing adjustment in renal impairment:

Clcr 50-80 mL/minute: Administer 75% of normal dose

Clcr 10-50 mL/minute: Administer 50% of normal dose

Clcr<10 mL/minute: Administer 25% of normal dose


Not for I.V. administration, inject slowly

Dietary Considerations

Should be taken with water 1 hour before or 1 hour after meals.

Patient Education

Take at regular intervals with a full glass of water; do not ingest large amounts of caffeine-containing beverages or foods; do not take more than the recommended dose

Nursing Implications

Not for I.V. administration, inject slowly; administer oral form around-the-clock rather than 4 times/day, 3 times/day, etc (ie, 12-6-12-6, not 9-1-5-9) to promote less variation in peak and trough serum levels; monitor vital signs, serum concentrations, and CNS effects (insomnia, irritability); encourage patient to drink adequate fluids (2 L/day) to decrease mucous viscosity in airways

Dental Health: Effects on Dental Treatment

Do not prescribe any erythromycin product to patients taking theophylline products. Erythromycin will delay the normal metabolic inactivation of theophyllines leading to increased blood levels; this has resulted in nausea, vomiting and CNS restlessness.

Dental Health: Vasoconstrictor/Local Anesthetic Precautions

No information available to require special precautions

Mental Health: Effects on Mental Status

May cause nervousness, restlessness, or insomnia

Mental Health: Effects on Psychiatric Treatment

May decrease serum lithium levels; monitor; barbiturates and carbamazepine may decrease dyphylline levels; may antagonize effects of benzodiazepines

Dosage Forms

[DSC] = Discontinued product

Elixir: Lufyllin®: 100 mg/15 mL (473 mL) [contains alcohol 20%]

Injection, solution (Dilor®): 250 mg/mL (2 mL) [DSC]

Tablet (Dilor®, Lufyllin®): 200 mg, 400 mg

International Brand Names

Dilor® (CA); Lufyllin® (CA)

Review Date: 1969-12-31 Reviewed By: Keywords: ,
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