A nurse is providing discharge instructions to a client who has asthma and is about to start taking theophylline (Theo-24). The nurse should tell the client that this medication might cause which of the following adverse effects?
A.
Constipation
B.
Oliguria
C.
Drowsiness
D.
Dysrhythmias
The Correct Answer and Explanation is:
The correct answer is D. Dysrhythmias.
Explanation
Theophylline is a methylxanthine used primarily for the treatment of asthma and other chronic obstructive pulmonary diseases (COPD). It works by relaxing the muscles around the airways and making breathing easier. However, it is important for patients to be aware of its potential side effects, particularly because theophylline has a narrow therapeutic index, meaning the difference between an effective dose and a toxic dose is small.
One of the significant adverse effects of theophylline is dysrhythmias. Dysrhythmias, or irregular heartbeats, can occur because theophylline can stimulate the heart and affect its electrical conduction system. High levels of theophylline in the blood can lead to serious cardiovascular effects, including tachycardia (rapid heartbeat), palpitations, and various types of arrhythmias. This is why regular monitoring of theophylline levels in the blood is crucial to prevent toxicity and associated cardiovascular issues.
Let’s briefly look at why the other options are less relevant:
- Constipation (A): Constipation is not commonly associated with theophylline use. Gastrointestinal side effects, like nausea and vomiting, are more frequent, but constipation is not a typical concern.
- Oliguria (B): Oliguria, or reduced urine output, is not a known adverse effect of theophylline. Theophylline can actually have diuretic effects, leading to increased urine output in some cases, but oliguria is not a recognized side effect.
- Drowsiness (C): Theophylline is a stimulant and is more likely to cause symptoms such as insomnia or restlessness rather than drowsiness. Drowsiness is not typically associated with theophylline therapy.
Overall, dysrhythmias are a well-documented and serious side effect of theophylline that patients should be monitored for, highlighting the importance of adherence to prescribed dosing and regular follow-up care.