Introduction: Pathophysiology and Factors Regulating Blood Pressure (BP)
Changes in heart rate, stroke volume, or total peripheral resistance cause modifications in BP. When extracellular fluid volume or plasma norepinephrine level rises, the patient’s heart rate or stroke volume are affected (Robinson, 2016). Total peripheral resistance is impacted by the processes increasing blood viscosity or narrowing the arteriolar radius. Commonly, BP is lower at night when a person is sleeping. The loss of such a nocturnal drop of BP is considered to be the major predictor of the risk for stroke (Robinson, 2016).
Pharmacodynamic Properties of Treatment
The treatment depends on intruding normal physiological mechanisms since there are no identifiable causes of hypertension. RAAS agents reduce BP by lowering water and sodium retention and vasoconstriction, as well as by raising vasodilation (Robinson, 2016). The action of adrenergic blockers is reflected in the rise in venous pooling in capacitance vessels and the reduction of peripheral vascular resistance. Calcium channel blockers increase the area of blood flow through widening resistance vessels (Robinson, 2016).
Selecting Antihypertensive Medications
It has been researched that the main advantage of pharmacological approaches to BP treatment is the lowered BP. Thus, all antihypertensive drugs are a priori regarded as successful and can be prescribed to patients. Despite occasional research results indicating the superiority of some drug group, there is not enough proof of such a tendency. According to the guidelines issued by the European Society of Hypertension (ESH) and the European Society of Cardiology (ESC), all of the abovementioned drugs are suitable for hypertensive patients (Mancia et al., 2013).
Monotherapy and Combination Therapy
Whereas monotherapy can be useful in some cases, the majority of patients require more than one pharmacological method of treatment. Thus, the question is not whether combination treatment is better but whether monotherapy should be tried at all (Mancia et al., 2013).
The major advantage and, at the same, time, disadvantage of monotherapy is the use of only one agent, so the effectiveness or its lack can be ascribed to that agent. However, there is a considerable limitation of this approach: when monotherapy proves unsuccessful, it may take much time to find a more suitable option (Mancia et al., 2013). The benefit of combination therapy is a prompter response to treatment. The limitation of this approach is that when one of the drugs is ineffective, it is not easy to find out which one it is (Mancia et al., 2013).
Endothelin Receptor Antagonists
While there is not clear whether increased levels of endothelin plasma are the cause or effect of hypertension, scholars note that the endothelin system occupies an important place in hypertension pathogenesis. Ambrisentan is used to eliminate the progression of hypertension (Galiè et al., 2013). Side effects include abdominal pain, swelling of legs, and skipped or rapid heartbeats. Bosentan is another oral endothelin-receptor antagonist that has proved to be effective in hemodynamics and exercise capacity (Galiè et al., 2013). Macitentan has such qualities as enhanced tissue penetration and sustained receptor building (Galiè et al., 2013). This drug has proved to reduce mortality and morbidity levels among hypertension patients.
Phosphodiesterase Type 5 Inhibitors (PDE-5is)
In addition to clinical benefits in hypertension treatment, all PDE-5is are approved for the management of erectile dysfunction (Galiè et al., 2013). Sildenafil is an orally active PDE-5i that promotes exercise capacity and hemodynamics. Tadalafil is a selective PDE-5i that has positive effects on hemodynamics and symptoms (Galiè et al., 2013). The side effect profile is largely related to vasolidation. The benefits and side effects of vardenafil are similar to those of the other two PDE-5is. Whereas sildenafil and tadalafil are approved for arterial hypertension patients, vardenafil is not.
The clinical use of prostacyclin in hypertension patients has been increased by the synthesis of stable analogs (Galiè et al., 2013). Beraprost is the first orally active and chemically stable prostacyclin analog. This drug does not show any hemodynamic advantages, and its tendency to enhance exercise capacity does not last long (Galiè et al., 2013). Epoprostenol is administered intravenously, and it improves hemodynamics and symptoms. Iloprost and treprostinil have a positive effect on exercise capacity, symptoms, and hemodynamics (Galiè et al., 2013).
The main goal of the pharmacological management of hypertension is the reduction in cardiovascular risk since these two issues are interrelated. The second important consequence is associated with the prevention of end-organ damage to eyes, kidneys, and brain (Robinson, 2016). To meet the mentioned objectives, it is crucial to mitigate the age-related rise of BP. Also, nurses should enhance the control of hypertension in various groups, such as adults, older adults, and patients with concurrent diabetes or hypertension. An important aspect is the spread of information among population so that people would realize the significance of controlling BP and noticing prehypertension (Robinson, 2016). Finally, it is necessary to reduce ethnic and other disparities and include patients of all ages in hypertension-preventing activities.
Galiè, N., Corris, P. A., Frost, A., Girgis, R. E., Granton, J., Jing, Z. C., … Keogh, A. (2013). Updated treatment algorithm of pulmonary arterial hypertension. Journal of the American College of Cardiology, 62(25D), 60-72.
Mancia, G., Fagard, R., Narkiewicz, K., Redon, J., Zanchetti, A., Böhm, M., … Zannad, F. (2013). 2013 ESH/ESC guidelines for the management of arterial hypertension. European Heart Journal, 34(28), 2159-2219.
Robinson, M. V. (2016). Hypertension. In T. M. Woo & M. V. Robinson (Eds.), Pharmacotherapeutics for advanced practice nurse prescribers (4th ed.) (pp. 1155-1178). Philadelphia, PA: F. A. Davis Company.