Anesthetic considerations of the herbal, kava.

The herbal remedy, kava, is reviewed, with special focus on the anesthetic management of the perioperative patient. Consumption of kava has potential cardiovascular consequences that could manifest in the perioperative period. Kava may act through inhibition of sodium and calcium channels to cause direct decreases in systemic vascular resistance and blood pressure. Kava inhibits cyclooxygenase to potentially cause a decrease in renal blood flow and to interfere with platelet aggregation. Kava may also cause adverse neurologic effects because of benzodiazepine and antidepressant activities on noradrenergic and/or serotoninergic pathways that may potentiate benzodiazepine and induction anesthetic potency and cause excessive perioperative sedation. Patients often do not disclose their use of herbal substances, and drug interaction can occur without being suspected as the cause for a change in patient homeostasis. A role for patient education about the potential adverse consequences of kava use in the perioperative period is suggested.

Impact of ginkgo biloba on the pharmacokinetics of digoxin.

Many medications are known to alter digoxin pharmacokinetics, including the herbal medication St. John's wort. An open-labeled, randomized, crossover trial was conducted in eight healthy human volunteers to determine if ginkgo biloba (GB) also alters the pharmacokinetics of digoxin. On two occasions separated by 2 weeks, subjects ingested digoxin, 0.5 mg. One week prior to each study phase, half of the volunteers were randomly initiated on GB therapy, 80 mg three times daily, that continued until the end of the study phase. Immediately prior to and for 36 hours following digoxin ingestion, multiple blood samples were collected for digoxin plasma concentration determination. No significant difference between treatments was observed with respect to AUC(0- infinity ) (digoxin alone: 21.0 +/- 8.6 [ng/mL] x h; digoxin + GB: 25.6 +/- 13.2 [ng/mL] x h). Additionally, no significant difference between therapies was observed with respect to C(max), T(max), or Cl(o). In six subjects, k(e) and t(1/2) were able to be determined. These parameters also did not differ significantly between treatments. In conclusion, within the context of the specific GB product used during this investigation, the concomitant use of GB and digoxin did not appear to have any significant effect on the pharmacokinetics of orally administered digoxin in healthy volunteers.

A survey of herbal product use in a dialysis population in Northwest Ohio.

OBJECTIVE: To identify herbal product use in a dialysis population. DESIGN AND SETTING: Cross-sectional survey conducted at 2 freestanding dialysis centers in Northwest Ohio. PATIENTS: Two hundred and sixteen hemodialysis and peritoneal dialysis patients who provided informed consent. INTERVENTION: All patients were surveyed by personal interview regarding use of herbal products. Patients identified as current users were asked questions about specific agents. Respondents reporting past but not current use were questioned about specific agents and reasons for discontinuation. RESULTS: Thirty-one patients reported taking herbal therapies. Twenty-six patients discontinued use before the survey. Sixteen different herbal products were reported being used in our study population. Those who reported ever using an herbal product were more likely to be employed or disabled and have higher education when compared with nonusers. CONCLUSION: Our data suggest a lower frequency of herbal product use in the dialysis population as compared with the general population and other chronically ill populations. Education and employment are factors associated with use. Many of the herbal therapies used potentially could have significant adverse effects in dialysis patients. These include effects on blood pressure, blood glucose, coagulation parameters, and electrolyte disturbances. Dialysis patients currently taking herbal products may not be reevaluating their need for continuation and may not be informing members of the nephrology care team about their use.