The product label: how pharmacokinetics and pharmacodynamics reach the prescriber.

The product label, or package insert, is the 'manual' for the safe and effective use of a drug. Important pharmacokinetic and pharmacodynamic properties of a drug product should appear in the label under specific sections, as required in the Code of Federal Regulations (CFR), using a format and language recommended by the Food and Drug Administration (FDA) in various guidances to the industry. The relevant regulations and guidance documents impacting on how this information is conveyed to the healthcare professional are discussed, with special emphasis on how the new proposed rule will impact upon how information is to be conveyed. With the availability of new clinical pharmacology information not available at the time of approval, package inserts for older drugs should be updated to reflect the new data and recommend the proper dosage regimen, enabling prescribers to optimise drug therapy and minimise possible adverse events.