How does an antihistamine work?

A) Obstructive sleep apnea (OSA):
Obstructive sleep apnea is a known risk factor for the development of hypertension. During episodes of sleep apnea, breathing repeatedly stops and starts, leading to disruptions in normal sleep patterns and potentially contributing to increased sympathetic nervous system activity, systemic inflammation, and endothelial dysfunction, all of which can elevate blood pressure over time.

B) The choice B was incorrect. While a diet high in potassium is generally associated with lower blood pressure due to its beneficial effects on blood vessel function and fluid balance, it is not considered a risk factor for developing hypertension. In fact, potassium-rich foods like fruits, vegetables, and legumes are often recommended as part of a heart-healthy diet to help manage blood pressure.

C) The choice C was incorrect. A high-density lipoprotein (HDL) level of 70 mg/dL is actually considered beneficial for cardiovascular health. HDL is often referred to as "good" cholesterol because it helps remove LDL (low-density lipoprotein) cholesterol from the bloodstream, reducing the risk of plaque buildup in the arteries. Having a high HDL level is typically associated with a lower risk of cardiovascular disease, including hypertension.

D) The choice D was incorrect. Benazepril is actually an antihypertensive medication, specifically an angiotensin-converting enzyme (ACE) inhibitor. It is used to treat hypertension, not as a risk factor for its development. ACE inhibitors work by relaxing blood vessels, which helps lower blood pressure. While taking certain medications like benazepril may contribute to the management of hypertension, they are not considered risk factors for its development.

E) Cigarette smoking:
Cigarette smoking is a well-established risk factor for the development of hypertension. Smoking cigarettes can lead to the constriction of blood vessels, increased heart rate, and damage to the lining of blood vessels, all of which can elevate blood pressure. Additionally, the chemicals in tobacco smoke can contribute to inflammation and oxidative stress, further exacerbating cardiovascular risk factors. Smoking cessation is an essential component of hypertension management and overall cardiovascular health.

A) By blocking the effects of histamine in the body:
Antihistamines are pharmacological agents that work by antagonizing the effects of histamine, a chemical mediator released by mast cells and basophils in response to allergens or other triggers. Histamine contributes to various allergic symptoms such as itching, sneezing, nasal congestion, and watery eyes. Antihistamines exert their effects by competitively binding to histamine receptors (specifically H1 receptors) on target cells, thereby preventing histamine from binding and exerting its physiological effects. By blocking histamine receptors, antihistamines inhibit the action of histamine, leading to the alleviation of allergy symptoms.

B) By reducing inflammation in the body:
While some medications, such as corticosteroids, exert anti-inflammatory effects by suppressing the immune response and inhibiting the production of inflammatory mediators, antihistamines primarily target histamine receptors and do not directly reduce inflammation. Although histamine release can contribute to inflammation, antihistamines mitigate allergic symptoms primarily by blocking the action of histamine rather than by directly reducing inflammation.

C) By increasing the production of histamine in the body:
This statement is inaccurate. Antihistamines do not increase the production of histamine; instead, they counteract the effects of histamine by blocking its activity at receptor sites. The primary mechanism of action of antihistamines involves blocking histamine receptors to prevent histamine from exerting its physiological effects.

D) By stimulating the immune system:
Antihistamines do not stimulate the immune system. Instead, they act as antagonists to histamine receptors, thereby inhibiting histamine-induced responses. While histamine is involved in immune responses and allergic reactions, antihistamines do not directly modulate immune function or stimulate immune activity. Their primary role is to alleviate allergy symptoms by blocking the effects of histamine."