Respiratory Drugs and Medications Q 22

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The effects of theophylline may be increased by:

  

     A. Phenobarbital

     B. Phenytoin

     C. Rifampin

     D. Cimetidine

    

    

Correct Answer: D. Cimetidine

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Cimetidine will increase the effects of theophylline. Other medications can affect the removal of theophylline from the body, which may affect how theophylline works. Examples include cimetidine, disulfiram, fluvoxamine, interferon, mexiletine, propranolol, rifampin, drugs used to treat seizures (such as carbamazepine, phenytoin).

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Option A: Theophylline, ephedrine, and phenobarbital combination is used to treat the symptoms of bronchial asthma, asthmatic bronchitis, and other lung diseases. theophylline, ephedrine, and phenobarbital relieves cough, wheezing, shortness of breath, and troubled breathing.

Option B: The effect of phenytoin, 100 mg thrice daily for 3 weeks, on theophylline disposition was studied in eight healthy volunteers. 2. The anticonvulsant significantly reduced the half-life of theophylline and this was associated with an increase in the rate of theophylline clearance.

Option C: The effect of rifampicin pre-treatment (600 mg daily for 6 days) on theophylline disposition at steady state was investigated in six healthy males. Following rifampicin treatment total plasma clearance of theophylline increased by 82%.

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