The question asks which medication might worsen congestive heart failure (CHF) in a susceptible individual. To answer this, we need to understand the impact of each listed drug on heart function, particularly in the context of CHF.
Furosemide is a loop diuretic commonly used in the treatment of CHF. It works by helping the kidneys eliminate unneeded water and salt from the body through urine. This reduces the volume of fluid circulating through the blood vessels, decreasing the load on the heart. Therefore, furosemide is generally beneficial for CHF patients as it helps alleviate symptoms such as swelling and shortness of breath, rather than exacerbating CHF.
Metoprolol is a beta-blocker that is used to manage several cardiovascular conditions, including CHF. It works by blocking beta-adrenergic receptors in the heart, which slows down the heart rate and reduces the force of the heart muscle's contractions. Initially, it was thought that beta-blockers were not safe for CHF patients due to their effect on reducing cardiac output. However, long-term use has been shown to improve the function of the heart and increase survival rates in CHF patients. Short-term effects, though, might include a decrease in cardiac output, which can be problematic in CHF patients who are unstable or in acute distress.
Metformin is primarily a medication for type 2 diabetes, not directly affecting heart function or cardiac output. It is generally considered safe in patients with CHF unless there are complicating factors such as kidney dysfunction, which is a contraindication due to the risk of lactic acidosis.
Acetaminophen, commonly used for pain and fever, has no direct impact on cardiac output or heart function. It is considered safe in recommended doses for patients with CHF as it does not exacerbate heart failure symptoms.
From the medications listed, while metoprolol might initially pose some risk due to its effect on cardiac output, it is generally beneficial in long-term CHF management. The other medications, furosemide, metformin, and acetaminophen, do not typically exacerbate CHF. In fact, furosemide is often part of the therapeutic regimen for managing CHF symptoms. Therefore, the correct answer depends significantly on the specific circumstances and stability of the CHF patient when considering metoprolol. For a patient in acute CHF distress or not yet stabilized on chronic CHF therapy, metoprolol could potentially exacerbate the condition temporarily.