Review Question - QID 9098

All of the following listed have been associated with increased postoperative bleeding due to their direct effect on platelet function EXCEPT St John’s wort, which exerts its effects on the CNS by inhibiting serotonin, norepinephrine, and dopamine reuptake by neurons.

Ginkgo biloba, ginseng, and garlic are all herbal remedies that have been associated with increased postoperative bleeding and related complications. All three are known to act directly on platelet function. Physicians should be aware not only of prescribed medications but also alternative nutraceuticals, herbal medications, and dietary supplements that are used by the patient.

Ang-Lee et al. review common herbal medications and their physiologic effects. They emphasize during the preoperative evaluation, physicians should explicitly elicit and document a history of herbal medication use. Physicians should be familiar with the potential perioperative effects of the commonly used herbal medications to prevent, recognize, and treat potentially serious problems associated with their use and discontinuation.

Bebbington et al. reported on persistent postoperative bleeding after total hip arthroplasty secondary to ginkgo biloba usage. They found the postoperative bleeding stopped 6 weeks after the ginkgo biloba usage was discontinued.

Illustration A shows the mechanism of aspirin, which targets cyclooxygenase 1, and thus inhibits the conversion of Arachiodonic acid to Prostaglandin. This leads to a decrease in platelet activation and aggregation.

Incorrect Answers:
Answer 2: Aged garlic extracts inhibits platelet aggregation by increasing cyclic nucleotides and inhibiting fibrinogen binding and platelet shape change.
Answer 3: ASA inhibits coagulation by inhibiting the production of prostaglandins and thromboxanes through irreversible inactivation of the cyclooxygenase enzyme.
Answer 4: Ginseng works through antiplatelet activity of panaxynol, a constituent of ginseng.
Answer 5: Ginkgo biloba is a popular nutraceutical for patients who have early dementia, intermittent claudication secondary to peripheral vascular disease, vertigo, and tinnitus. It is reported to improve mental alertness and cognitive deficiency. It has antiplatelet properties as a result of one of its components, ginkgolide B, which displaces platelet-activating factor from its receptor binding sight.