What occurs when one drug affects the pharmacokinetics of another drug?

When one drug affects the pharmacokinetics of another drug, it means that the absorption, distribution, metabolism, or excretion of one drug is influenced by the presence of the other. This interaction can lead to alterations in the effects or side effects of the affected drug.

For example, if Drug A inhibits the metabolism of Drug B, Drug B may remain in the system longer, increasing its concentration and potentially enhancing both its therapeutic effects and side effects. Conversely, Drug A could reduce the efficacy of Drug B by altering its pharmacokinetics, leading to subtherapeutic levels or reduced clinical effectiveness.

Understanding these interactions is crucial for healthcare providers to avoid adverse reactions and to optimize therapy by modifying dosages or choosing alternative therapies based on how drugs may interact through their pharmacokinetic profiles.