Search results
Results from the WOW.Com Content Network
Theophylline, also known as 1,3-dimethylxanthine, is a drug that inhibits phosphodiesterase and blocks adenosine receptors. [1] It is used to treat chronic obstructive pulmonary disease (COPD) and asthma . [ 2 ]
It is a combination drug containing three active ingredients - theophylline, ephedrine, phenobarbital. [2] This medication relaxes the smooth muscle of the airways, making breathing easier. [ 3 ] The common side effects of Tedral include gastrointestinal disturbances , dizziness , headache and lightheadedness .
[9] [7] [10] A ratio of 5:1 theophylline to ephedrine is usually used in combinations of the drugs. [11] Later research found that the combination was no more effective for asthma than theophylline alone but produced more side effects. [9] [1] [12] [7]
Even less safe are drugs such as digoxin, a cardiac glycoside; its therapeutic index is approximately 2:1. [12] Other examples of drugs with a narrow therapeutic range, which may require drug monitoring both to achieve therapeutic levels and to minimize toxicity, include dimercaprol, theophylline, warfarin and lithium carbonate.
Isoniazid may increase the amount of phenytoin in the body. The doses of phenytoin may need to be adjusted when given with isoniazid. [50] [51] Isoniazid may increase the plasma levels of theophylline. There are some cases of theophylline slowing down isoniazid elimination. Both theophylline and isoniazid levels should be monitored. [52]
Still, the blood values are approximately equal between the arterial and venous sides for most substances, with the exception of acid–base, blood gases and drugs (used in therapeutic drug monitoring (TDM) assays). [6] Arterial levels for drugs are generally higher than venous levels because of extraction while passing through tissues. [6]
This gives a = 100 μg/mL if the drug stays in the blood stream only, and thus its volume of distribution is the same as that is = 0.08 L/kg. If the drug distributes into all body water the volume of distribution would increase to approximately V D = {\displaystyle V_{D}=} 0.57 L/kg [ 8 ]
It was a combination of theophylline, ephedra, [1] and hydroxyzine, and taken by mouth. [ 2 ] [ 3 ] It is no longer manufactured in the US due to approval of ephedra being withdrawn by the FDA . [ citation needed ]