Respiratory Drugs and Medications Q 20
A client with which of the following conditions may experience a dangerous or fatal side effect of theophylline?
A. Cardiac disorder
B. Diabetes
C. Renal disease
D. Hepatic disease
Correct Answer: A. Cardiac disorder
A client with a heart condition may experience dangerous stimulation from this drug. Use cautiously in patients who have cardiac arrhythmias (excluding bradyarrhythmias), as it may exacerbate arrhythmias. Theophylline should be administered cautiously with all the other choices, but the consequences are most dangerous or possibly fatal for clients with heart conditions.
Option B: Use cautiously in patients with hyperthyroidism, as increased theophylline clearance may occur. Theophylline has a very narrow therapeutic window, and its interaction with various other drugs has led to the limitation of its use. The serum theophylline concentrations require monitoring directly to avoid toxicity as the adverse effects of theophylline are related to its plasma concentration and have been observed when plasma concentrations exceed 20 mg/L. Some patients have also experienced adverse effects at low plasma concentrations. The dose gradually increases until achieving therapeutic plasma concentrations. This approach reduces side effects.
Option C: Serum theophylline concentrations should be checked after the initiation of therapy, before increasing dose and if any signs or symptoms of toxicity appear. Worsening of the current illness, an occurrence of a new illness or any change in the patient’s treatment protocol that may alter theophylline clearance should also prompt the physician to check serum concentrations of theophylline. Attention should also be necessary for the infusion site.
Option D: Use cautiously in patients with a hepatic impairment such as cirrhosis, cholestasis, acute hepatitis because there is an increased risk of severe and potentially fatal complications. This risk exists because clearance decreases by 50% or more in these patients. Frequent monitoring and dose reduction of theophylline are necessary for these patients.