Drug-drug interactions
The issue of drug-drug interactions has generated significant concern within the pharmaceutical industry and among US and European regulatory authorities in recent years.
The co-administration of different drugs or dietary supplements can affect the therapeutic outcome of a drug. These interactions may include alterations in the pharmacokinetics of the drug, such as alterations in the absorption, distribution, metabolism and excretion (ADME) of the drug. Alternatively, the interactions can also result in alterations in the pharmacodynamic properties of the drug, e.g. the co-administration of a receptor antagonist and an agonist for the same receptor.
Many drug interactions are due to alterations in drug metabolism, by enzime inhibition/induction. In the same way, drug interactions can also affect the absorption and consequently the bioavailabilty of a drug, by inhibition/induction of transporter proteins, such as the p-glycoprotein.
In our group, we are currently studying the effect that some flavonoid formulations can have in the metabolism of drugs wich are substrates for esterases. We are also studying their effect on the bioavailability of the same drugs and for that purpose we are using the Caco-2 cell model, rat hepatocytes and pure enzymes.
