In pharmacology, we often talk about targets instead of receptors. Targets are simply the place on the cell or in the body that a drug affects. This can be a receptor (or receptors), or it can be a general region. In some cases, like with certain drugs that affect the kidneys and CNS, it is far more helpful to memorize the target than the receptor.
For example, hydrochlorothiazide, a thiazide diuretic, increases urine excretion from the kidneys by blocking sodium reabsorption in the distal convoluted tubule. This process begins with the blocking of a receptor, but then starts a very long chain of events that culminate in a net effect. If you know what the distal tubule does, however, and how variations in its contents affect the rest of the body, then you know that a thiazide diuretic…
1. Is a mild-moderate diuretic
2. Will cause potassium loss
3. Will lower your blood pressure
So remember to eat your bananas (unless you are taking spironolactone), and go study some physiology!