The __, (the pharmacologic effect), can be therapeutic and/or cause toxicity. For many drugs, the __ is dose/drug concentration related; the higher the dose, the higher drug concentrations in the body and the more intense __ up to a maximum effect It is desirable that S/E and/or toxicity of drugs occurs at higher drug concentrations than the drug concentrations needed for the therapeutic effect. Unfortunately, unwanted S/E often occur concurrently with the therapeutic doses.