Learning Objective:
By the end of this lesson, learners will be able to describe the pharmacological strategies for reducing blood pressure, including their effects on total peripheral resistance (TPR), cardiac output (CO), and body fluid volume, and explain the compensatory homeostatic responses such as reflex tachycardia and edema.
Drug Strategy for Blood Pressure Reduction:
- Decrease Total Peripheral Resistance (TPR) – relaxes vascular smooth muscle to lower systemic vascular resistance.
- Decrease Cardiac Output (CO) – reduces heart rate and/or stroke volume.
- Decrease Body Fluid Volume – promotes diuresis to reduce circulating blood volume.
Potential Homeostatic Responses:
- Reflex tachycardia – increased sympathetic activity as a compensatory response to reduced BP.
- Edema – increased renin-angiotensin-aldosterone activity leading to fluid retention.
