Herb-drug interactions: focus on pharmacokinetics

Medicinal Plant-derived Phytochemicals in Detoxification

The average worldwide human life expectancy is 70 years, with a significantly higher value in Western societies. Many modern diseases are not associated with premature mortality but with a decreased quality of life in aged patients and an excessive accumulation of various toxic compounds in the human body during life. Today, scientists are especially interested in finding compounds that can help increase a healthy lifespan by detoxifying the body. Phytotherapy with specific approaches is used in alternative medicine to remove toxins from the body. Worldwide, research is conducted to identify medicinal plant-derived molecules that, with few or no side effects, may protect the liver and other organs. This review provides updated information about the detoxification process, the traditional and modern use of the most effective medicinal plants, their active metabolites as detoxifying agents, and the mechanisms and pathways involved in the detoxification process. Among medicinal plants with substantial detoxifying properties, a major part belongs to the Asteraceae family (Silybum marianum, Cynara scolymus, Arctium lappa, Helichrysum species, Inula helenium, and Taraxacum officinale). The most widely used hepatoprotective phytocomponent is silymarin, a standardized extract from the Silybum marianum seeds containing a mixture of flavonolignans. Many polysaccharides, polyphenols, and terpenoids have a detoxifying effect. Overall, scientific data on medicinal plants used in phytotherapeutic practice worldwide provides an understanding and awareness of their efficacy in detoxification.

Effects of berberine and hwangryunhaedok-tang on oral bioavailability and pharmacokinetics of ciprofloxacin in rats

Hwangryunhaedok-Tang (HR) and berberine-containing single herbs are used to treat bacterial infection and inflammatory diseases in eastern Asia. The combination of berberine-containing herbal medicines and ciprofloxacin can be an excellent antibacterial chemotherapy against multidrug resistance bacteria. To evaluate the pretreatment effect of berberine and HR, vehicle, berberine (25 and 50 mg/kg/day), and HR (1.4 g/kg/day) were daily administered to rats for five consecutive days. On day 6, ciprofloxacin was administered (10 mg/kg, i.v. and 20 mg/kg, p.o.) to rats. To assess cotreatment effect of berberine and ciprofloxacin, berberine (50 mg/kg) and ciprofloxacin (20 mg/kg) were coadministered by single oral gavage. Pharmacokinetic data were estimated by noncompartmental model. Compared with ciprofloxacin alone (control group), coadministration of berberine (50 mg/kg) and ciprofloxacin significantly decreased C(max) of ciprofloxacin (P < 0.05). In addition, the pretreatment of berberine (50 mg/kg/day) and HR (1.4 g/kg/day) significantly decreased C(max) and AUC(0→∞), compared with control group (P < 0.05). The oral bioavailability of ciprofloxacin was reduced by cotreatment of berberine and pretreatment of berberine and HR. Our results suggest that the expression of P-glycoprotein and organic anion and/or organic cation transporters (OAT/OCT) could take a role in reduced oral bioavailability of ciprofloxacin by berberine and HR.

The use of herbal medications and dietary supplements by people with mental illness

This study examined the relationship between herbal medication and dietary supplement (HMDS) use and mental health characteristics. Data are drawn from a national household survey of the United States' civilian, non-institutionalized population (N = 9,585). Psychiatric medication and HMDS use, psychiatric diagnoses and treatment needs, utilization and satisfaction were assessed. Compared to non-users, HMDS users were more likely to perceive themselves as having mental health needs, to have received mental health and primary care treatment, and to be dissatisfied with their overall healthcare. Psychiatric medication use was not related to HMDS use, and in multivariate analyses, HMDS use was associated with perceived mental health needs. Differences in use of specific HMDS between those with and without a psychiatric disorder were also examined. The use of HMDS warrants particular attention in persons with perceived mental health problems as these individuals may be turning to HMDS use for treatment of their symptoms.

Therapeutic armamentarium for treating depression

Depressive disorders are highly prevalent and are a leading cause of disability, morbidity, and mortality worldwide; however, they often remain undertreated or untreated. This article provides a broad overview of the many strategies for treating depression. More than 24 antidepressant medications and depression-focused psychotherapies are available as first-choice options for treating depression. When patients have not had a satisfactory treatment response, the 2 main strategies are switching to an alternative antidepressant therapy or adding a second antidepressant therapy. A large number of medication combinations have been reported in the literature, and some have been shown to be effective in controlled studies. Nonstandard alternatives to conventional antidepressant treatments include exercise, light therapy, sleep deprivation, and various complementary and alternative therapies. For more chronic and refractory forms of depression, various neuromodulation therapies are available or are being investigated. Because depressive disorders are common in primary care and other medical settings, medical practitioners should be aware of the therapeutic armamentarium available for treating depression.

Antiviral drug disposition and natural health products: risk of therapeutic alteration and resistance

The HIV/AIDS patient population is known to use natural health products (NHPs) in addition to the several antiretroviral drugs that constitute the treatment regimen for this disease. This review focuses on NHPs and their potential for interactions with antiretroviral agents resulting in therapeutic alterations or resistance. There are conflicting published medical literature reports and very few well-documented human clinical studies that unequivocally demonstrate if this concomitant use increases the risk of interaction/adverse reaction with these therapeutic products. This article outlines some findings from the Canadian domestic adverse reaction case reports associated with the use of antiretrovirals and NHPs. These adverse reaction case reports were specifically examined for patients taking NHPs together with their highly active antiretroviral therapy during or around the time when the adverse reaction developed. Together, the case reports and limited human clinical studies suggest that the risk for therapeutic alterations and resistance can exist due to changes in pharmacokinetic parameters with concomitant use of these therapeutic products.

Tic disorders in childhood

Despite our familiarity with tic disorders, their management remains challenging. The difficulty seldom relates to the diagnosis, which is usually based on the history, but rather in dealing with the impact of the tics and multiple comorbidities. The child and family must be educated and must be taught how to facilitate a positive attitude among others who come in contact with the patient. Knowledge and acceptance of the tics by other family members, peers, teachers, and coaches often become central to the child's well-being. Although many children can be managed without pharmacotherapy, medications are often central to achieving success. The goals of therapy and the appropriate choice of medication must be individualized. We are frequently challenged not only by the wide array of medication choices available but also by the decision of which symptom to treat first. The tics, despite being flamboyant, are often viewed by the child and family as less disabling than co-occurring conditions, such as attention-deficit hyperactivity disorder, obsessive-compulsiveness, or rage. Even when tics are the major issue, patients must define their goals for therapy. It is unreasonable to expect a complete resolution of tics and safety usually rules in favor of better tolerated but potentially less efficacious therapies. Developing strategies to minimize the lifelong impact of the multiple components of Tourette syndrome is an essential aspect of the care of these patients.

Use of Herbal Medicine in Primary Care Patients With Mood and Anxiety Disorders

Studies have documented the increasing use of complementary and alternative medicine over the last decade, especially in distressed individuals with symptoms of anxiety, depression, and pain. Herbal medicine is a specific form of complementary and alternative medicine often used by individuals seeing traditional medical practitioners and, hence, has the potential to interact with other medically prescribed treatments. The study examined the use of herbal medicine in a group of primary care patients with symptoms of anxiety and depression. The rate of use of herbal medicines was 11%, and use was selectively associated with a diagnosis of major depression, higher education, and a lower burden of medical illness. Use was not associated with receipt of pharmacotherapy or psychotherapy for anxiety or depression.

Serious psychiatric and neurological adverse effects of herbal medicines -- a systematic review

OBJECTIVE

Psychiatric and neurological patients frequently try herbal medicines often under the assumption that they are safe. The aim of this systematic review was to provide a summary of recent data on severe psychiatric and neurological adverse effects of herbal remedies.

METHOD

Computerized literature searches were carried out to identify all reports of psychiatric and neurological adverse effects associated with herbal medicines. These data were subsequently extracted, validated and summarized in narrative and tabular form.

RESULTS

Numerous case reports comprise a diverse array of adverse events including cerebral arteritis, cerebral oedema, delirium, coma, confusion, encephalopathy, hallucinations, intracerebral haemorrhage, and other types of cerebrovascular accidents, movement disorders, mood disturbances, muscle weakness, paresthesiae and seizures. Several fatalities are on record. They are caused by improper use, toxicity of herbal ingredients, contamination and adulteration of preparations and herb/drug interactions.

CONCLUSION

Herbal medicines can cause serious psychiatric and neurological adverse effects.

St John's wort: a systematic review of adverse effects and drug interactions for the consultation psychiatrist

St. John's wort is an herb commonly used in Europe for decades and more recently the topic of scientific investigation in this country. St. John's wort has been found more effective than placebo and equally as effective as tricyclic antidepressants in the short-term management of mild-to-moderate depression. Comparisons to selective serotonin reuptake inhibitors have provided equivocal data. While it is generally well tolerated in clinical use, there is accumulating evidence of significant interactions with drugs. This evidence-based presentation of the literature includes a brief description of pharmacodynamics and clinical applications, followed by a systematic review of adverse effects, toxicity, and drug interactions.