Final answer:
Naproxen may interact with feverfew when taken for migraine prevention due to both substances' ability to inhibit platelet aggregation, thus increasing bleeding risk.
Step-by-step explanation:
The medication that may interact with feverfew in a client taking it for migraine prevention is naproxen. Feverfew is known to inhibit platelet aggregation, which increases the risk of bleeding. Since naproxen is a nonsteroidal anti-inflammatory drug (NSAID) that can also affect platelet function and increase bleeding risk, combining it with feverfew may heighten this risk. Therefore, it is important for clients taking feverfew for migraine prevention to avoid concurrent use of naproxen and similar drugs that can amplify bleeding risk.