Posture changes platelet inhibition time after ingestion of prasugrel

Several studies have suggested that supine posture during pill ingestion prolongs oesophageal transit time. Whether ingesting prasugrel in an upright position leads to reduced platelet reactivity during percutaneous coronary intervention remains unclear.

A total of 20 people were randomly assigned to ingest 60 mg of prasugrel in either the supine or upright position. Platelet reactivity was analysed using the point-of-care assay VerifyNow.

In the upright position, the velocity of platelet inhibition was highest between 20 and 40 min. (Δ = 101.9 P2Y12 reaction units (PRU)). In the supine position, the highest value was seen between 40 and 60 min. (Δ = 56.85 PRU). Time to reach the cut-off for reducing peri- and post-operative risk of thrombosis showed a mean difference of 8 min. in favour of the upright group.

A trend towards faster reduction of platelet reactivity was seen when ingesting prasugrel in the upright position compared with the supine position.

This work was supported by Oda and Hans Svenningsens Foundation (grant number: BOF-10109). The foundation had no part in the collection, analysis or interpretation of data, or in the writing of the report or the decision to submit the work for publication.

This trial was registered with clinicaltrials.gov (NCT01365741).