Doseresponse Curves

Conventionally dose is plotted on the horizontal and response on the vertical axis. The slope of the dose-response curve defines the extent to which a desired response alters as the dose is changed. A

3 Greek: cheir, a hand

4 R (rectus) and S (sinister) refer to the sequential arrangement of the constituent parts of the molecule around the chiral center.

steep-rising and prolonged curve indicates that a small change in dose produces a large change in drug effect over a wide dose range, e.g. with the loop diuretic, frusemide (furosemide) (used in doses from 20 mg to over 250 mg/d). By contrast the dose-response curve for the thiazide diuretics soon reaches a plateau and the clinically useful dose range for bendrofluazide (bendroflumethiazide), for example, extends from 5 mg to 10 mg; increasing the dose beyond this produces no added diuretic effect though it adds to toxicity.

Dose-response curves may be constructed for wanted effects, and also for unzvanted effects (see Fig. 7.1, below).

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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