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Herbal remedies.

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Complementary Therapies↗

St John's Wort: effect on CYP3A4 activity.

BACKGROUND: St John's Wort is a widely used herbal product. Information regarding its potential for drug interactions is required for responsible treatment of patients using St John's Wort. CYP3A4 is a metabolic enzyme implicated in most clinically significant drug-drug interactions. OBJECTIVE: To determine the in vivo effect of reagent-grade St John's Wort extract on CYP3A4 activity through evaluation of urinary 6-beta-hydroxycortisol/cortisol ratios. METHODS: Thirteen subjects ranging in age from 18 to 25 years participated in this unblinded, multiple-dose, single-treatment before-after trial conducted in a university-based pharmacokinetics and biopharmaceutics laboratory. Each subject ingested a 300-mg tablet of reagent-grade St John's Wort extract standardized to 0.3% hypericin three times a day for 14 days. Baseline and posttreatment CYP3A4 activity was assessed with the urinary 6-beta-hydroxycortisol/cortisol ratio after a 24-hour urine collection. RESULTS: The mean +/- SD urinary 6-beta-hydroxycortisol/cortisol ratio significantly increased (P = .003) from a baseline value of 7.1 +/- 4.5 to 13 +/- 4.9. The mean +/- SD percentage increase was 114% +/- 95%, with a range from -25% to 259%. All but one subject had an increase in the ratio. CONCLUSIONS: Treatment with St John's Wort for 14 days resulted in significant increases in the urinary 6-beta-hydroxycortisol/cortisol ratio. This finding suggests that St John's Wort is an inducer of CYP3A4.

Adolescent↗

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.

Adult↗

Different effects of St John's wort on the pharmacokinetics of simvastatin and pravastatin.

OBJECTIVE: St John's Wort, a widely used herbal product, is an inducer of CYP3A4 and it decreases blood concentrations of CYP3A4 substrates. The effects of St John's Wort on the pharmacokinetics of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors simvastatin (an inactive lactone pro-drug) and pravastatin were determined in this study. METHODS: Sixteen healthy male subjects (n = 8 in group 1 and n = 8 in group 2) took a St John's Wort caplet (300 mg) or matching placebo three times a day for 14 days in a double-blind, crossover study. On day 14, a single oral dose of 10 mg simvastatin and 20 mg pravastatin was given to subjects in group 1 and group 2, respectively. Blood samples were obtained during a 24-hour period after the administration of each drug. RESULTS: Repeated St John's Wort treatment tended to lower plasma simvastatin concentration and significantly (P <.05) lowered concentrations of simvastatin hydroxy acid, its active metabolite. The peak concentration in plasma (ratio, 0.72 of placebo) of simvastatin hydroxy acid tended to be decreased and its area under the plasma concentration-time curve between time zero and 24 hours after administration (ratio, 0.48 of placebo) was significantly decreased (P <.05) by St John's Wort. On the other hand, St John's Wort did not influence plasma pravastatin concentration. No significant differences were observed in the elimination half-life of simvastatin or pravastatin between the placebo and St John's Wort trials. CONCLUSIONS: This study showed that St John's Wort decreases plasma concentrations of simvastatin but not of pravastatin. Because simvastatin is extensively metabolized by CYP3A4 in the intestinal wall and liver, which are induced by St John's Wort, it is likely that this interaction is partly caused by the enhancement of the CYP3A4-mediated first-pass metabolism of simvastatin in the small intestine and liver.

Adult↗

Effect of St John's wort on the pharmacokinetics of fexofenadine.

BACKGROUND: St John's wort is a popular over-the-counter dietary supplement and herbal remedy that has been implicated in drug interactions with several substrates of P-glycoprotein. The effect of St John's wort on P-glycoprotein activity in vivo was examined with use of fexofenadine as selective probe drug. METHODS: A 3-period, open-label, fixed-schedule study design was used. Fexofenadine, 60 mg, was administered orally before administration of St John's wort, with a single dose of St John's wort (900 mg), and after 2 weeks of treatment with St John's wort (300 mg 3 times a day) to determine P-glycoprotein activity. RESULTS: A single dose of St John's wort significantly (P <.05) increased the maximum plasma concentration of fexofenadine by 45% and significantly (P <.05) decreased the oral clearance by 20%, with no change in half-life or renal clearance. Long-term administration of St John's wort did not cause a significant change in fexofenadine disposition relative to the untreated phase. Compared with the single-dose treatment phase, long-term St John's wort caused a significant 35% decrease (P <.05) in maximum plasma concentration and a significant 47% increase (P <.05) in fexofenadine oral clearance. CONCLUSIONS: A single dose of St John's wort resulted in a significant inhibition of intestinal P-glycoprotein. Long-term treatment with St John's wort reversed the changes in fexofenadine disposition observed with single-dose administration.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Cytochrome P450 phenotypic ratios for predicting herb-drug interactions in humans.

OBJECTIVES: Phytochemical-mediated modulation of cytochrome P450 (CYP) activity may underlie many herb-drug interactions. Single-time point phenotypic metabolic ratios were used to determine whether long-term supplementation of St John's wort, garlic oil, Panax ginseng, and Ginkgo biloba affected CYP1A2, CYP2D6, CYP2E1, or CYP3A4 activity. METHODS: Twelve healthy volunteers (6 females) were randomly assigned to receive either St John's wort, garlic oil, P ginseng, or G biloba for 28 days. For each subject, a 30-day washout period was interposed between each supplementation phase. Probe-drug cocktails of midazolam, caffeine, chlorzoxazone, and debrisoquin (INN, debrisoquine) were administered before supplementation (baseline) and at the end of supplementation. Presupplementation and postsupplementation phenotypic trait measurements were determined for CYP3A4, CYP1A2, CYP2E1, and CYP2D6 with the use of 1-hydroxymidazolam/midazolam serum ratios (1-hour sample), paraxanthine/caffeine serum ratios (6-hour sample), 6-hydroxychlorzoxazone/chlorzoxazone serum ratios (2-hour sample), and debrisoquin urinary recovery ratios (8-hour collection), respectively. RESULTS: Comparisons of presupplementation and postsupplementation ratios indicated that St John's wort significantly induced the activity of CYP2E1 and CYP3A4 (P <.0001). Among female subjects, St John's wort produced significantly greater increases in CYP3A4 phenotypic ratios that appeared to be unrelated to body mass index. This finding is suggestive of a sexual dimorphism in CYP3A4 inducibility. Garlic oil reduced CYP2E1 activity by 39% (P =.030), whereas no significant effect on CYP activity was observed for P ginseng and G biloba. CONCLUSIONS: Single-time point phenotypic metabolic ratios may provide a practical means of predicting CYP-mediated herb-drug interactions in humans.

Adult↗

Coordinate induction of both cytochrome P4503A and MDR1 by St John's wort in healthy subjects.

BACKGROUND: Many drugs are cosubstrates of cytochrome P450 (CYP) 3A and MDR1; furthermore, their disposition is markedly affected by pretreatment with inducing agents, including St John's wort. Such drug interactions reflect induction of both proteins through a common mechanism involving the steroid X receptor/pregnane X receptor. However, the relative contributions of enhanced metabolism and efflux transport to the overall induction process are unknown. METHODS: The effects of 12 days' pretreatment with St John's wort on the disposition of selected in vivo probe drugs were determined in 21 young healthy subjects. Midazolam after oral and intravenous administration was used to assess CYP3A activity in both the intestinal epithelium and the liver, whereas the disposition of fexofenadine after an oral dose was assumed to be a measure of MDR1 function, and the oral plasma concentration-time profile of cyclosporine (INN, ciclosporin) was considered to reflect both CYP3A and MDR1 activities. RESULTS: St John's wort markedly affected the plasma concentration-time profiles of all of the drugs, with associated increases in their clearance. With midazolam, the enhancement was considerably less after intravenous administration (approximately 1.5-fold) than after oral administration (approximately 2.7-fold), and estimated intestinal and hepatic extraction ratios were higher by approximately 1.2- to 1.4-fold. By contrast, the oral clearances of fexofenadine and cyclosporine were equally increased by approximately 1.6-fold and 1.9-fold, respectively; these changes were both statistically less than for midazolam's oral clearance and greater than its estimated intestinal extraction. CONCLUSIONS: Although the disposition of all 3 drugs was altered by St John's wort, the extent of induction measured by oral clearance was different with CYP3A activity (midazolam), apparently increasing more than MDR1 function (fexofenadine), whereas with cyclosporine the change in oral clearance appeared to be more closely associated with the increase in MDR1 rather than CYP3A, despite the fact that both proteins are importantly involved in its disposition. These discordances indicate that, although a common molecular mechanism may be involved, the quantitative aspects of induction are complex and depend on the particular drug and the relative contributions of CYP3A and MDR1 in its disposition.

Adult↗

An integrative medicine approach to premenstrual syndrome.

Complementary and alternative medicine (CAM) approaches are widely used by women with premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD). This article provides a comprehensive review of the medical literature on clinical applications of CAM for these conditions. The information was collected via a Medline review dating back to 1966 and subsequent selected review of bibliographies from these articles for non-Medline referenced but relevant clinical studies. For many of the therapies discussed, there is a lack of conclusive evidence either confirming or refuting efficacy. For other therapies, including certain herbal and nutritional approaches, the use of exercise, and the use of mind-body approaches, there is substantial evidence of efficacy. This review will be relevant to the practicing clinician seeking to become aware of and to understand the relevance of the complementary/alternative therapies being used by his/her patients for PMS and PMDD.

Cimicifuga↗

Treating depression comorbid with anxiety--results of an open, practice-oriented study with St John's wort WS 5572 and valerian extract in high doses.

Depressive disorders in comorbidity with anxiety disorders represent an frequently diagnostic and therapeutic problem. The studies quoted here prove that the symptoms associated with anxiety that severely afflict patients can be clearly improved more quickly with a combination therapy of St John's wort extract and valerian extract than with St John's wort monotherapy. The combination therapy was well tolerated, no significant side-effects occurred. Further studies are necessary to compare the combination treatment with other forms of therapy (serotonin- and noradrenalin re-uptake inhibitors).

Antidepressive Agents↗

Psychiatrists' experience and views regarding St John's Wort and 'alternative' treatments.

OBJECTIVE: This study aims to ascertain the experience and views of psychiatrists in relation to St John's Wort and alternative treatments generally. METHOD: A questionnaire was posted to all members of the Royal Australian and New Zealand College of Psychiatrists living in Australia or New Zealand. RESULTS: Of the 1910 mailed questionnaires, 862 (45%) were returned. Eighty per cent of respondents had patients who had used the herb. Side-effects and drug interactions were reported by 28% and 8% respectively of these psychiatrists. Some adverse events were described as serious. Psychiatrist attitudes about St John's Wort and alternative treatments were positive overall and psychiatrists seemed willing to recommend St John's Wort despite limited evidence of its usefulness. CONCLUSIONS: Psychiatrists in Australia and New Zealand regularly manage patients who take St John's Wort and a considerable number actually recommend the treatment. However, they also report side-effects and drug interactions. Psychiatrists should routinely enquire about their patients' use of alternative treatments, be mindful of possible side-effects and in particular be aware of the dangers of combining St John's Wort with other psychotropics.

Adult↗

Hypomania induced by herbal and pharmaceutical psychotropic medicines following mild traumatic brain injury.

The use of herbal medicines has become a very common practice. While many are safe enough to be available over-the-counter, they may pose risks due to interactions with pharmaceutical medications and effects in specific clinical populations. The case of a female patient with a history of mild traumatic brain injury and resulting depression is presented. She experienced hypomania after adding St John's wort and Ginkgo biloba to her regimen of fluoxetine and buspirone, which remitted after discontinuation of the herbal medicines. Implications for interactions between various psychopharmacologic agents, including herbal medicines and selective serotonin reuptake inhibitors (SSRIs), as well as the need for appropriate patient and health care provider education are discussed.

Adult↗

Content analysis and stability evaluation of selected commercial preparations of St. John's wort.

Content analysis and stability studies were performed for the commercial products of St. John's wort. Six marketed formulations were analyzed for their hypericin and pseudohypericin content. These products were standardized to contain 0.3% hypericin. Results revealed total hypericin as 7.72-38.57% of the labeled claim with varying concentrations of pseudohypericin. Stability studies were carried out under three different storage conditions: 1) 25+/-2 degrees C, 60+/-5%RH for six months, 2) 40+/-2 degrees C, 75+/-5%RH for six months, and 3) 50 degrees C for one month. Tablet formulations were also analyzed for their hardness and friability. Stability studies revealed significant decrease in the content of the marker compounds with time.

Anthracenes↗

Over-the-counter psychotropics: a review of melatonin, St John's wort, valerian, and kava-kava.

Use and availability of alternative healthcare products have revived in the last few years. The prevalence of supplement use in the United States is largely unknown but is thought to be widespread. In this article, four of the common substances used to treat emotional problems are reviewed. The plant or substance description, clinical indications, evidence of therapeutic efficacy, mechanisms of therapeutic actions, dosages and regimens, different commercially available preparations, and adverse effects and toxicities are described for melatonin, St John's wort, valerian, and kava-kava. That a product is "natural" does not mean that it is either safe or effective. Many supplements are potent drugs that lack sufficient data on safety, dose-response relationships, drug interactions, and purity.

Anti-Anxiety Agents↗

Natural medicines for alcoholism treatment: a review.

Alcoholism is a serious problem throughout the world. The development of alcoholism remedies have medical, social and economical significance. In view of the pitfalls of psychological dependence and adverse behavioural effects of synthetic drugs, the development of low toxicity and high efficiency medicines derived from natural products exhibits expansive market prospects. Based on these considerations, we summarize briefly folk application of traditional hangover remedies and clinical application of herbal complex and patent medicines for alcoholism treatment. We have reviewed the effects of natural medicines on intake, absorption and metabolism of alcohol, as well as the protective effects on alcohol-induced acute and chronic tissue injury.

Alcoholism↗