Use of References in Responses from Scandinavian Drug Information Centres.

Background: The aim of this study was to compare use of references in responses from Scandinavian drug information centres (DICs). Methods: Six different fictitious drug-related queries were sent to each of seven Scandinavian DICs. The six queries concerned adverse effects, pharmacokinetics, pregnancy, complementary medicine, polypharmacy, and breast feeding. References in the responses were categorised into five types of drug information sources: primary (original studies), secondary (reviews), tertiary (drug monographs, handbooks, etc.), DIC database, or personal communication. Results: Two hundred and forty-four references were used in the 42 responses. The mean number of references varied from 3.0 to 10.6 for the six queries. The largest difference between centres with regard to number of references used (range 1⁻17) was found for the query on complementary medicine. In total, 124 references (50.8%) were tertiary, and only 10 of the 42 responses (23.8%) did not have any tertiary references included. Complementary medicine, breast feeding, and pregnancy were query types associated with relatively frequent use of primary references. Use of DIC database was not uncommon, but personal communications were seldom used. Conclusions: Scandinavian DICs differ substantially in number and type of references to identical drug-related queries. Tertiary sources are mainly preferred irrespective of type of query.

Abuse Potential of Pregabalin: A Systematic Review.

BACKGROUND: Several case reports and epidemiological studies have raised concern about the abuse potential of pregabalin, the use of which has increased substantially over the last decade. Pregabalin is, in some cases, used for recreational purposes and it has incurred attention among drug abusers for causing euphoric and dissociative effects when taken in doses exceeding normal therapeutic dosages or used by alternative routes of administration, such as nasal insufflation or venous injection. The magnitude of the abuse potential and the mechanism behind it are not fully known. OBJECTIVE: The aim of this study was to present a systematic review of the data concerning the abuse potential of pregabalin. METHODS: We performed a systematic literature search and reviewed the preclinical, clinical and epidemiological data on the abuse potential of pregabalin. RESULTS: We included preclinical (n = 17), clinical (n = 19) and epidemiological (n = 13) studies addressing the abuse potential of pregabalin. We also reviewed case reports (n = 9) concerning abuse of pregabalin. The preclinical studies indicated that pregabalin possesses modulatory effects on the GABA and glutamate systems, leaving room for an abuse potential. Further, clinical studies reported euphoria as a frequent side effect in patients treated with pregabalin. The majority of case reports concerning abuse of pregabalin involved patients with a history of substance abuse and, similarly, epidemiological studies found evidence of abuse, especially among opiate abusers. CONCLUSIONS: Overall, the available literature suggests an important clinical abuse potential of pregabalin and prescribers should pay attention to signs of abuse, especially in patients with a history of substance abuse.

Impaired Glucose Tolerance in Healthy Men Treated with St. John's Wort.

The purpose of this study was to examine whether the over-the-counter herbal medicinal plant St. John's wort affects glucose tolerance in healthy men. To do this, we included 10 healthy men who were examined by a 2-hr oral glucose tolerance test on three occasions: A: baseline; B: after 21 days of treatment with St. John's wort; and C: at least 6 weeks after the last capsule of St. John's wort was ingested. Plasma glucose, serum insulin and C-peptide levels were measured during an oral glucose tolerance test and used for estimation of area under the concentration-time curve (AUC) as well as indices of insulin sensitivity and insulin secretion. We found that treatment with St. John's wort increased total and incremental glucose AUC and 2-hr plasma glucose levels. Surprisingly, this effect was sustained and even further increased 6 weeks after the last capsule of St. John's wort was taken. No effect on indices of insulin sensitivity was seen, but indices of insulin secretion were reduced even after adjustment for insulin sensitivity. In conclusion, this study indicates that long-term treatment with St. John's wort may impair glucose tolerance by reducing insulin secretion in young, healthy men. The unregulated use of this over-the-counter drug might be a risk factor for impaired glucose tolerance and type 2 diabetes.

Intake of St John's wort improves the glucose tolerance in healthy subjects who ingest metformin compared with metformin alone.

AIMS: Our objective was to investigate the steady-state pharmacokinetic and pharmacodynamic interaction between the antidepressive herbal medicine St John's wort and the antidiabetic drug metformin. METHODS: We performed an open cross-over study in 20 healthy male subjects, who received 1 g of metformin twice daily for 1 week with and without 21 days of preceding and concomitant treatment with St John's wort. The pharmacokinetics of metformin was determined, and a 2 h oral glucose tolerance test was performed. RESULTS: St John's wort decreased the renal clearance of metformin but did not affect any other metformin pharmacokinetic parameter. The addition of St John's wort decreased the area under the glucose concentration-time curve [702 (95% confidence interval, 643-761) vs. 629 min*mmol/L (95% confidence interval, 568-690), P = 0.003], and this effect was caused by a statistically significant increase in the acute insulin response. CONCLUSIONS: St John's wort improves glucose tolerance by enhancing insulin secretion independently of insulin sensitivity in healthy male subjects taking metformin.