Impact of cytochrome P-450 inhibition by cimetidine and induction by carbamazepine on the kinetics of hypericin and pseudohypericin in healthy volunteers

Status analysis of herbal drug therapies in epilepsy: advancements in the use of medicinal plants with anti-inflammatory properties

BACKGROUND

Use of plants and plant products in health care has shown exponential increase in past two decades.

INTRODUCTION

In-spite of the availability of well-established pharmacotherapy for epilepsy, a large no of population still explores alternative treatments due to refractory seizures, adverse effects of drugs, chronic treatment, inaccessibility of standard therapies in rural areas and the social stigma attached to the disease. Various studies on medicinal plants showed the protective effect of herbals in animal models of epilepsy.

METHOD

In the present review, a status analysis of the traditional use of various medicinal plants in epilepsy with a special focus on plats having anti-inflammatory potential is recorded.

RESULT AND CONCLUSION

The shortcomings of research on medicinal plants which needs to be explored further in order to tackle the growing need of safer and effective drugs for epilepsy are discussed. Overall, there is a huge scope of herbal drugs in CNS disorders especially epilepsy, either as an adjunct by reducing the dose and thus side effects of standard anti-epileptic drugs or as standalone agent . Although, there is still an urgent need of well planned randomized controlled clinical trials to validate their efficacy and safety.

Pharmacokinetics of the co-administration of boceprevir and St John's wort to male and female healthy volunteers

BACKGROUND

St John's wort (SJW; Hypericum perforatum) induces CYP3A4 that is involved in the metabolism of the hepatitis C virus (HCV) protease inhibitor boceprevir. Reduced boceprevir exposure and efficacy would contribute to therapeutic failure and increase the risk for resistance development. Boceprevir is co-administered with interferon/ribavirin, and depression has been described frequently in patients undergoing HCV treatment. Patients may purchase over-the-counter herbals to manage depression, and knowing the interaction between SJW and boceprevir is desirable.

METHODS

This Phase I, open-label, three-period, cross-over pharmacokinetic study enrolled healthy males and females who, following consent and screening procedures, were randomized to receive SJW on days 1-14, SJW plus boceprevir (SJW on days 22-35 and together on days 31-35) and boceprevir on days 52-56, separated by 7 day washout periods, or the same treatment in the opposite order. Pharmacokinetic sampling was performed at the end of each phase.

RESULTS

Seventeen (11 female) subjects completed the study and no serious adverse events were reported. Geometric mean ratios (GMRs) and 90% CIs for boceprevir (with SJW versus alone) AUC(0-8), C(max) and C8 were 0.91 (0.87-0.96), 0.94 (0.82-1.07) and 1.00 (0.79-1.27), respectively. GMRs and 90% CIs for hypericin, the active component of SJW, (with boceprevir versus alone) AUC(0-8), C(max) and C(8) were 1.23 (1.10-1.38), 1.32 (1.16-1.52) and 1.37 (1.19-1.58), respectively.

CONCLUSIONS

SJW did not have a clinically significant effect on boceprevir plasma concentrations (or those of its metabolite), suggesting that SJW and boceprevir can be safely co-administered.

Herb-drug interactions with St John's wort (Hypericum perforatum): an update on clinical observations

St John's wort (SJW) extracts, prepared from the aerial parts of Hypericum perforatum, contain numerous pharmacologically active ingredients, including naphthodianthrones (e.g., hypericin and its derivatives), phloroglucinols derivatives (e.g., hyperforin, which inhibits the reuptake of a number of neurotransmitters, including serotonin), and flavonoids. Such extracts are widely used for the treatment of mild-to-moderate depression. As a monotherapy, SJW has an encouraging safety profile. However, relevant and, in some case, life-threatening interactions have been reported, particularly with drugs which are substrate of cytochrome P450 and/or P-glycoprotein. Well-documented SJW interactions include (1) reduced blood cyclosporin concentration, as suggested by multiple case reports as well as by clinical trials, (2) serotonin syndrome or lethargy when SJW was given with serotonin reuptake inhibitors, (3) unwanted pregnancies in women while using oral contraceptives and SJW, and (4) reduced plasma drug concentration of antiretroviral (e.g., indinavir, nevirapine) and anticancer (i.e., irinotecan, imatinib) drugs. Hyperforin, which is believed to contribute to the antidepressant action of St John's wort, is also strongly suspected to be responsible of most of the described interactions.

Toxicity and drug interactions associated with herbal products: ephedra and St. John's Wort

Health care providers are being increasingly confronted with the use of herbal medications by their patients. It is imperative that patients be questioned regarding herbal preparation use and that health care providers become familiar with these agents. Research into the active components and mechanisms of action of various herbals is ongoing [350]. Long-range studies need to be performed to follow patients for efficacy or toxicity in chronic use [351,352]. Adverse reactions to herbal remedies should be reported to the FDA MedWatch at http://www.fda.gov/medwatch. As withany therapeutic agent, risk of use must always be weighed against potential benefits.