NONHERBAL DIETARY SUPPLEMENTS

Herbal medicines fall into the broader category of dietary supplements that also includes vitamins, minerals, amino acids, enzymes, and animal extracts. Data on the safety of these agents in the perioperative period are scant. High-dose vitamin use, particularly of the fatsoluble vitamins (i.e., A, D, E, and K) can be associated with acute and chronic toxicity. Glucosamine and chondroitin sulfate, which are used for joint disorders by many patients having orthopedic procedures, have not been associated with perioperative complications, although chondroitin sulfate belongs to the same group of glycosaminoglycan molecules as heparin and may have minor anticoagulant effects.^[119] Whether long-term chondroitin sulfate use can cause thrombocytopenia is unknown. Creatine, a dietary supplement used by athletes to enhance performance, has been associated with renal dysfunction in at least one case.^[120] There are preliminary data that exogenous melatonin, a hormone produced by the pineal gland, may be useful in preventing and treating postoperative delirium.^[121]