II. Precautions
- Theophylline is listed here for completeness, not for recommended use
- In the developed world, Theophylline and its adverse effects are largely supplanted by better agents
- Limited roles may be found in refractory cases under specialty care, and in underdeveloped world regions
III. Indications
- Limited utility where standard of care Asthma Management is available
- Theophylline and Aminophylline were replaced by Inhaled Beta Adrenergic Agonists (e.g. Albuterol) and Ipratropium Bromide
IV. Preparations: Methylxanthines
- Theophylline
- Oral administration only
- Aminophylline
- IV form of Theophylline
- Water soluble salt of Theophylline
- Aminophylline has higher solubility allows for IV administration
- Other Methylxanthines
V. Mechanism
- Xanthines are isolated from plants Camellia sinensis and Coffea arabica
- Activity: Xanthines and Methylxanthines in general
- Xanthines at high dose inhibit phosphodiesterase (PDE) and Prostaglandin production
- PDE catalyzes cAMP, with increased cAMP levels when PDE is inhibited
- cAMP mediates adrenergic induced bronchodilation
- Block Adenosine
- Results in CNS and cardiac stimulation
- Moderate cellular Calcium
- Xanthines at high dose inhibit phosphodiesterase (PDE) and Prostaglandin production
- Effects: Theophylline
- Bronchial Smooth Muscle relaxation (high doses of Theophylline)
- Peripheral vasodilation (not central)
- CNS and cardiac stimulant
- Diuretic
- Anti-inflammatory (at low doses of Theophylline)
VI. Dosing
- Theophylline 150 to 300 mg orally twice daily
- Patients should not modify dose from prescribed (even for missed dosing)
- Doubling dose for a missed dose may result in Theophylline toxicity
VII. Pharmacokinetics: Oral Theophylline
VIII. Adverse Effects
IX. Drug Interactions
- Agents that increase Theophylline half life and serum concentrations
- Alcohol
- Cimetidine
- Ciprofloxacin
- Diltiazem
- Erythromycin
- Oral Contraceptives
- Propranolol (very strong effect, doubles the Theophylline concentration)
- Verapamil
- Agents that decrease Theophylline half life and serum concentrations
-
Sympathomimetics
- Increased CNS and cardiac toxicity
X. Resources
- Theophylline XR Tablet (DailyMed)
- Aminophylline Intravenous Solution (DailyMed)
XI. References
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 90
- Falk (2016) Am Fam Physician 94(6): 454-62 [PubMed]
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Related Studies
| theophylline (on 3/15/2023 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| THEOPHYLLINE ER 300 MG TAB | Generic | $2.38 each |
| THEOPHYLLINE ER 300 MG TABLET | Generic | $2.54 each |
| THEOPHYLLINE ER 400 MG TABLET | Generic | $0.64 each |
| THEOPHYLLINE ER 600 MG TABLET | Generic | $0.96 each |