Theophylline, also known as 1,3-dimethylxanthine, is a drug that inhibits phosphodiesterase and blocks adenosine receptors. It is used to treat chronic obstructive pulmonary disease (COPD) and asthma. Its pharmacology is similar to other methylxanthine dr + some more technical info. Theophylline produces bronchodilation and modest anti-inflammatory effects through nonselective inhibition of phosphodiesterase isoenzymes, antagonism at A1 and A2 adenosine receptors, and elevation of intracellular cyclic AMP. It is well absorbed after oral dosing, primarily metabolized in the liver by CYP1A2 with contributions from CYP2E1 and CYP3A4, and has a narrow therapeutic index requiring therapeutic drug monitoring; plasma concentrations are commonly targeted between 5 and 15 micrograms per milliliter. Clearance is influenced by age, smoking status, hepatic function and interacting drugs, and the molecule also exerts immunomodulatory effects including enhancement of histone deacetylase activity which can affect corticosteroid responsiveness.
Parent: Theophylline / Pentoxifylline
Parent: Theophylline/ Caffeine
Parent: Theophylline
Parent: Diprophylline/ Theophylline
Parent: Theophylline/ Theophylline Monohydrate
Parent: Theophylline
Parent: Theophylline/ Theophylline-Ethylenediamine Hydrate
Parent: Theophylline/ Theophylline-Ethylenediamine
Typical API quality specifications control related xanthine impurities such as theobromine (3,7-dimethylxanthine), caffeine (1,3,7-trimethylxanthine), 1-methylxanthine, 3-methylxanthine, xanthine and dimethyluric derivatives. Common acceptance criteria used in manufacture and quality control limit individual related compounds to approximately 0.1 to 0.5 percent by weight and total impurities to about 0.5 to 1.0 percent, with particularly potent or genotoxic impurities restricted at tighter levels often below 0.05 percent. Typical example limits might be theobromine <= 0.2 percent, caffeine <= 0.1 percent, 1-methylxanthine <= 0.2 percent and total related compounds <= 0.5 percent, but exact limits should follow the product specific specification and regulatory filing. Identification and quantitation of these impurities are routinely performed using validated HPLC-UV or LC-MS methods with appropriate system suitability and sensitivity.
Theophylline is used primarily as a bronchodilator in the management of COPD and asthma, often as an adjunct when inhaled therapies are insufficient; it has also been used historically for neonatal apnea and other respiratory indications.
Use has declined because safer and more effective inhaled long-acting bronchodilators and inhaled corticosteroids are available, and theophylline has a narrow therapeutic index, significant drug interactions and variable pharmacokinetics that require monitoring to avoid toxicity.
Theophylline works by nonselective inhibition of phosphodiesterase enzymes, increasing intracellular cAMP, and by antagonizing adenosine receptors (A1 and A2), producing bronchodilation and central nervous system stimulation; it also has immunomodulatory effects such as enhancing histone deacetylase activity.
Common side effects include nausea, vomiting, headache, insomnia and palpitations; at higher plasma concentrations patients are at risk for tachyarrhythmias and seizures.
