Which drug type constricts blood vessels to raise blood pressure?

• A. Open blood vessels
• B. Constricts blood vessels to raise BP
• C. Dilate blood vessels
• D. Decrease blood clotting

Answer: (B)

Drugs that constrict blood vessels are called vasoconstrictors or vasopressors. They raise blood pressure by tightening vascular smooth muscle, especially through alpha-adrenergic receptors, which increases intracellular calcium and causes arteriolar and venous constriction. This increases systemic vascular resistance and venous return, lifting the mean arterial pressure—useful in acute hypotension or shock. The statement describing constricting blood vessels to raise blood pressure matches this mechanism. Dilating vessels would lower BP, and decreasing clotting doesn’t directly raise blood pressure.