Drug-drug interactions

Cyprotex is a specialist provider of ADME and PK services and provide a range of in vitro drug-drug interaction assays.

The most common types of metabolic drug-drug interactions are the inhibition and induction of the drug metabolising enzymes. These interactions can cause increased or decreased drug exposures when two or more drugs are co-administered. For example, cytochrome P450 inhibition (CYP450) may increase the plasma levels of co-administered drugs leading to toxicity. Conversely, if a CYP450 enzyme is induced it may increase the metabolism of the co-administered compound; this can reduce plasma levels resulting in decreased efficacy or an increased formation of a toxic metabolite. For more background information on DDI studies, see our online ADME Guide.

Cyprotex provide a range of services to investigate drug-drug interactions including cytochrome P450 inhibition, cytochrome P450 time dependent inhibition, cytochrome P450 induction (catalytic activity and mRNA assessment) and UGT1A1 inhibition. Cyprotex also offer more detailed Ki service in order to determine the inhibitor affinity to the enzyme and indicate the type of inhibition observed.

Investigating if any of the main CYP isoforms are involved in the in vitro metabolism of a drug is also important in determining whether a clinical DDI study is necessary. To this end, Cyprotex provide a cytochrome P450 reaction phenotyping service  using recombinant enzyme.