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Description
Brand name: Unicontin 400
Active substance: Theophylline
Packaging: blister sheet 10 x 400 mg slow release tablets
Shipped from: India
Theophylline, also known as dimethylxanthine, is a methylxanthine drug used in therapy for respiratory diseases such as COPD or asthma under a variety of brand names. As a member of the xanthine family, it bears structural and pharmacological similarity to caffeine. It is naturally found in tea, although in trace quantities (~1 mg/L),[1] significantly less than therapeutic doses.
The main actions of theophylline involve:
* relaxing bronchial smooth muscle
* increasing heart muscle contractility and efficiency: positive inotropic
* increasing heart rate: positive chronotropic
* increasing blood pressure
* increasing renal blood flow
* some anti-inflammatory effects
* central nervous system stimulatory effect mainly on the medullary respiratory center.
Bioavailability is 100%. However, taking the drug late in the evening may slow the absorption process, without affecting the bioavailability. Taking the drug after a meal high in fat content will also slow down the absorption process, without affecting the bioavailability.
The main mechanism of action of theophylline is that of adenosine receptor antagonism. Theophylline is a non-specific adenosine antagonist, antagonizing A1, A2, and A3 receptors almost equally, which explains many of its cardiac effects and some of its anti-asthmatic effects.
Another proposed mechanism of action includes a non-specific inhibition of phosphodiesterase enzymes, producing an increase in intracellular cyclic AMP; however, this is not known with certainty.
The use of theophylline is complicated by the fact that it interacts with various drugs, chiefly cimetidine and phenytoin, and that it has a narrow therapeutic index, so its use must be monitored to avoid toxicity. It can also cause nausea, diarrhea, increase in heart rate, arrhythmias, and CNS excitation. Its toxicity is increased by erythromycin, cimetidine, and fluoroquinolones.
Before taking any prescription medicine, it is important that you consult your doctor!
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