A nurse is caring for a client who is receiving terbutaline to treat preterm labor. Which of the following findings should the nurse identify as a potential adverse effect of this medication?
A.
Hot flashes
B.
Heart palpitations
C.
Shortness of breath
D.
Bradycardia
The correct answer and Explanation is :
The correct answer is B. Heart palpitations.
Terbutaline is a beta-2 adrenergic agonist commonly used to delay preterm labor by relaxing the uterine muscles and preventing contractions. However, due to its stimulation of beta-adrenergic receptors, particularly in the cardiovascular and pulmonary systems, it has several potential adverse effects.
Explanation:
- Mechanism of Action:
Terbutaline works primarily by stimulating beta-2 receptors, which are located in the smooth muscles of the uterus, bronchioles, and blood vessels. By stimulating these receptors, it causes smooth muscle relaxation, leading to bronchodilation in the lungs and reduced uterine contractions. However, beta-2 agonists can also have effects on the heart (beta-1 stimulation), particularly when used in higher doses or prolonged therapy. - Heart Palpitations:
Terbutaline can inadvertently stimulate beta-1 adrenergic receptors in the heart, causing an increase in heart rate (tachycardia) and sensations of heart palpitations. This occurs because beta-1 receptors, primarily located in the heart, lead to increased cardiac output and myocardial oxygen demand, resulting in a feeling of pounding or irregular heartbeats (palpitations). This is the most common cardiovascular adverse effect. - Other Options:
- A. Hot flashes: While terbutaline may cause flushing or sweating, hot flashes are not a common or direct adverse effect of the medication.
- C. Shortness of breath: Terbutaline is a bronchodilator and is often used to treat respiratory conditions like asthma. While it can cause a rapid heart rate, which may feel like breathlessness, it typically improves respiratory function.
- D. Bradycardia: Bradycardia (slow heart rate) is not a common side effect of terbutaline. In fact, the medication usually increases the heart rate.
In summary, heart palpitations are a potential adverse effect of terbutaline due to its systemic beta-adrenergic effects, particularly on the cardiovascular system. Monitoring the client’s heart rate and rhythm is essential during treatment.