Losartan is similar to enalapril in all features except:
**Core Concept**
Losartan and enalapril are both used to treat hypertension and heart failure. They belong to different classes of antihypertensive medications: losartan is an angiotensin II receptor antagonist (ARB), while enalapril is an angiotensin-converting enzyme (ACE) inhibitor.
**Why the Correct Answer is Right**
Losartan works by blocking the action of angiotensin II at its receptor, thereby preventing vasoconstriction and reducing blood pressure. In contrast, enalapril inhibits the conversion of angiotensin I to angiotensin II, also reducing blood pressure. This difference in mechanism of action is crucial in distinguishing between these two classes of medications.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because losartan and enalapril both have similar effects on the renin-angiotensin-aldosterone system (RAAS), leading to decreased blood pressure and fluid retention.
**Option B:** This option is incorrect because both losartan and enalapril can cause cough as a side effect, although this is more common with ACE inhibitors like enalapril.
**Option C:** This option is incorrect because both medications can be used to treat heart failure by reducing afterload and improving cardiac output.
**Clinical Pearl / High-Yield Fact**
When choosing between ARBs and ACE inhibitors, consider the patient's risk of cough, which is more common with ACE inhibitors. Additionally, be aware that ARBs like losartan may be preferred in patients with a history of angioedema.
**Correct Answer: A.** Losartan is similar to enalapril in all features except that it is not a prodrug and does not require hydrolysis to its active form.