An agent which affects blood pressure by increasing the flow of urine and thus reducing the volume of fluid In the body Is called:

A diuretic is an agent that increases the flow of urine, thereby reducing the volume of fluid in the

body and affecting blood pressure. Diuretics are commonly used to treat hypertension, heart failure,

and edema. By promoting the excretion of sodium and water, they help decrease blood volume and

lower blood pressure.

Emetic: An agent that induces vomiting.

Depressant: A substance that slows down the central nervous system.

Cathartic: A substance that accelerates defecation.

Reference:

"Diuretics." American Heart Association, https://www.heart.org/en/health-topics/high-bloodpressure/high-blood-pressure-medications/diuretics