Lack of effect of St John's Wort on carbamazepine pharmacokinetics in healthy volunteers.

BACKGROUND: St John's Wort is a popular herbal product used by approximately 7% of patients with epilepsy. Previous reports have described reductions in concentrations of CYP3A4 substrates indinavir and cyclosporine (INN, ciclosporin) associated with St John's Wort. OBJECTIVE: Our objective was to determine the effect of St John's Wort on steady state carbamazepine and carbamazepine-10,11-epoxide pharmacokinetics. METHODS AND SUBJECTS: Eight healthy volunteers (5 men; age range, 24-43 years) participated in this unblinded study. Subjects received 100 mg of carbamazepine twice daily for 3 days, 200 mg twice daily for 3 days, and then 400 mg once daily for 14 days. Blood samples were collected before and 1, 2, 4, 6, 8, 10, 12, and 24 hours after the dose on day 21. The subjects then took 300 mg of St John's Wort (0.3% hypericin standardized tablet) 3 times daily with meals and with carbamazepine for 14 days. On day 35, blood sampling was repeated. Plasma samples were analyzed for carbamazepine and carbamazepine-10,11-epoxide with HPLC. We compared carbamazepine and carbamazepine-10,11-epoxide noncompartmental pharmacokinetic parameter values before and after St John's Wort with a paired Student t test. RESULTS: We found no significant differences before or after the administration of St John's Wort in carbamazepine peak concentration (7.2 +/- 1 mg/L before versus 7.6 +/- 1.3 mg/L after), trough concentration (4.8 +/- 0.5 mg/L before versus 4.3 +/- 0.8 mg/L after), area under the plasma concentration-time curve (142.4 +/- 12.9 mg x h/L before versus 143.8 +/- 27.2 mg x h/L after), or oral clearance (2.8 +/- 0.3 L/h before versus 2.9 +/- 0.6 L/h after). Similarly, no differences were found in peak concentration (2 +/- 0.5 mg/L before versus 2.1 +/- 0.4 mg/L after), trough concentration (1.3 +/- 0.3 mg/L before versus 1.4 +/- 0.3 mg/L after), and area under the plasma concentration-time curve (37.5 +/- 7.4 mg x h/L before versus 41.9 +/- 10.3 mg x h/L after) of carbamazepine-10,11-epoxide. CONCLUSIONS: The results suggest that treatment with St John's Wort for 14 days did not further induce the clearance of carbamazepine.

Improving the current system for supplying organs for transplantation.

The United States currently relies on a voluntary, altruistic system for supplying organs for transplantation. It is now generally recognized that this system, as currently operated, produces a seriously inadequate supply of organs. A number of scholars have argued that some type of (generally unspecified) market system is necessary. Two articles appearing in the Journal of Health Politics, Policy and Law have proposed relatively specific market systems for increasing the supply of organs. In this paper we argue that market systems are at best premature. In particular, there is little to suggest that any type of market system for organs will be permitted in the United States in the foreseeable future. We present data that strongly suggest that the current voluntary, altruistic system has not been developed to its full potential and offer a number of specific suggestions for improving the system.

Marketing the concept of becoming a potential organ donor.

Medical technology now enables thousands of people with terminal organ diseases to return to productive lives. Thousands more, however, will die because suitable donor organs are not currently available. Despite an early call for marketing approach to the problem of recruiting potential organ donors, little progress has been made to date. The author reviews the current literature on organ donation, discusses previous organ donation research conducted by a team he led, and makes suggestions for marketing the concept of becoming a potential organ donor.

A model of willingness to become a potential organ donor.

This article presents two models of the decision to become a potential organ donor. In the first model the act of carrying or requesting an organ donor card is related to values and factual knowledge regarding organ donation, through intervening attitude and willingness constructs. A sample of 286 students is used to test this model via the LISREL computer program for modeling latent variables. All hypothesized relationships had the predicted sign and were significant. This model is extended by adding the variables attitude towards death, prior blood donation, and age of subject to the model. A second sample of 365 adults from the local community is used to test the second model via LISREL. With two exceptions in the adult sample, all hypothesized relationships had the predicted sign and were significant. Where the two models overlap the results are generally similar. Implications of the models for marketing the act of becoming a potential organ donor are discussed.

Knowledge regarding organ donation: identifying and overcoming barriers to organ donation.

Four-hundred and fifty-five undergraduate students, 26 MBA students, and 465 people from the surrounding community responded to 21 true/false questions regarding factual knowledge about organ donation. The mean number of correct answers was 74.6%. The correct response rate, however, varied widely over questions. Four questions with very large error rates suggest possible 'barriers to donation'. Specifically, these questions concerned religious support for organ donation, the concept of brain death, the normally rigid separation of physician teams who are primarily responsible for the welfare of the donor and donee, and a mistaken belief that to be valid an organ donor card must be filed with the U.S. Department of Health and Human Services. Knowledge of organ donation facts was found to be related to whether subjects carried or requested an organ donor card, their attitude towards organ donation and their willingness to donate their own organs or the organs of a deceased loved one. These findings suggest strategies for raising public support for organ donation.