∞ generated and posted on 2015.12.31 ∞

The branch of pharmacology that deals with a drug's impact on the body.

Pharmacodynamics deals with the impact of drugs on targets, typically as a function of drug concentrations, whereas pharmacokinetics deals with both the maintenance and loss of those concentrations.

That impact can include both positive (wanted) and negative (unwanted) effects on bodies. Primary pharmacodynamics are positve, that is, efficacy effects of drugs. Contrast Pharmacokinetics.

Secondary pharmacodynamic include drug side effects or toxicities. Drug dosing can be limited by side effects, resulting in loss of potential for positive, that is, primary pharmacodynamic effects.

The time between dosing and indeed the danger of using certain drugs is also a function of secondary pharmacodynamic effects as also are the doses at which those effects become more likely relative to the doses at which positive effects become likely (see Therapeutic index).