Cmax refers to the maximum concentration of a drug in the bloodstream after it has been administered. It is an important pharmacokinetic parameter that helps determine how quickly and effectively a medication works in the body. Cmax is influenced by factors such as the route of administration, dosage, and the drug's absorption rate. Understanding Cmax is crucial for healthcare professionals when prescribing medications. It helps in assessing the drug's efficacy and safety, ensuring that patients receive the right dose to achieve the desired therapeutic effect without causing toxicity.