Final answer:
To ensure a medication's effectiveness and safety, it is necessary to reach efficacy before toxicity. Pharmacokinetic and toxicokinetic studies, alongside clinical trials, help determine the optimal therapeutic dose that is both effective and safe for use.
Step-by-step explanation:
It is crucial to reach efficacy before toxicity in drug development to ensure that a medication is both effective and safe for human use. To know when efficacy has been reached, pharmacokinetic analysis and dose-response relationships are evaluated during clinical trials. Dose proportionality assessments and information from toxicokinetic studies help establish the margin of safety, comparing the concentrations that produce the intended effect (efficacy) against those that could cause harm (toxicity).
Indicators such as LD-50 (lethal dose for 50% of a population) and ED-50 (effective dose for 50% of a population) support these determinations, ensuring the dose prescribed is therapeutically effective without being hazardous. Through clinical trial phases, particularly phase I and phase II, researchers gain insight into a drug's safety and determine the optimal therapeutic dose range.