Aspirin
Aspirin is currently employed in the prophylactic treatment
of transient cerebral ischemia, to reduce the incidence
of recurrent myocardial infarction and to decrease mortality
in postmyocardial infarction patients. Aspirin blocks
thromboxane A2 synthesis from arachidonic acid in platelets
by irreversibly acetylating and thus inhibiting cyclooxygenase,
a key enzyme in prostaglandin synthesis. The
aspirin-induced inhibition of thromboxane A2 synthesis
last for the life of the platelet (approximately 7–10 days)
[56].
A case report demonstrated a patient treated with aspirin
for 5 years experienced bleeding of the eye and blurred
vision after self-medication with ginkgo for 1 week [33].
After stopping ginkgo, there was no recurrence of bleeding
over a 3-month follow-up period. The interaction is likely
due to an additive effect on platelet function as ginkgolide B
from ginkgo is a potent PAF receptor antagonist [62].
A clinical study [34] performed on six healthy volunteers
showed that a tamarind extract incorporated in a traditional
meal increased plasma levels of aspirin and salicylic acid