Herb-drug interactions: a literature review

Herbs are often administered in combination with therapeutic drugs, raising the potential of herb-drug interactions. An extensive review of the literature identified reported herb-drug interactions with clinical significance, many of which are from case reports and limited clinical observations.
Cases have been published reporting enhanced anticoagulation and bleeding when patients on long-term warfarin therapy also took Salvia miltiorrhiza (danshen). Allium sativum (garlic) decreased the area under the plasma concentration-time curve (AUC) and maximum plasma concentration of saquinavir, but not ritonavir and paracetamol (acetaminophen), in volunteers. A. sativum increased the clotting time and international normalised ratio of warfarin and caused hypoglycaemia when taken with chlorpropamide. Ginkgo biloba (ginkgo) caused bleeding when combined with warfarin or aspirin (acetylsalicylic acid), raised blood pressure when combined with a thiazide diuretic and even caused coma when combined with trazodone in patients. Panax ginseng (ginseng) reduced the blood concentrations of alcohol (ethanol) and warfarin, and induced mania when used concomitantly with phenelzine, but ginseng increased the efficacy of influenza vaccination. Scutellaria baicalensis (huangqin) ameliorated irinotecan-induced gastrointestinal toxicity in cancer patients.
Piper methysticum (kava) increased the 'off' periods in patients with parkinsonism taking levodopa and induced a semicomatose state when given concomitantly with alprazolam. Kava enhanced the hypnotic effect of alcohol in mice, but this was not observed in humans. Silybum marianum (milk thistle) decreased the trough concentrations of indinavir in humans. Piperine from black (Piper nigrum Linn) and long (P. longum Linn) peppers increased the AUC of phenytoin, propranolol and theophylline in healthy volunteers and plasma concentrations of rifamipicin (rifampin) in patients with pulmonary tuberculosis. Eleutheroccus senticosus (Siberian ginseng) increased the serum concentration of digoxin, but did not alter the pharmacokinetics of dextromethorphan and alprazolam in humans. Hypericum perforatum (hypericum; St John's wort) decreased the blood concentrations of ciclosporin (cyclosporin), midazolam, tacrolimus, amitriptyline, digoxin, indinavir, warfarin, phenprocoumon and theophylline, but did not alter the pharmacokinetics of carbamazepine, pravastatin, mycophenolate mofetil and dextromethorphan. Cases have been reported where decreased ciclosporin concentrations led to organ rejection. Hypericum also caused breakthrough bleeding and unplanned pregnancies when used concomitantly with oral contraceptives. It also caused serotonin syndrome when used in combination with selective serotonin reuptake inhibitors (e.g. sertraline and paroxetine).
In conclusion, interactions between herbal medicines and prescribed drugs can occur and may lead to serious clinical consequences. There are other theoretical interactions indicated by preclinical data. Both pharmacokinetic and/or pharmacodynamic mechanisms have been considered to play a role in these interactions, although the underlying mechanisms for the altered drug effects and/or concentrations by concomitant herbal medicines are yet to be determined. The clinical importance of herb-drug interactions depends on many factors associated with the particular herb, drug and patient. Herbs should be appropriately labeled to alert consumers to potential interactions when concomitantly used with drugs, and to recommend a consultation with their general practitioners and other medical carers.

Healthy parks, healthy people : the health benefits of contact with nature in a park context : a review of current literature

This review identifies significant research that has not previously been compiled. It will provide key information for decision making by park managers, forming the basis of a program of future research to overcome the limited knowledge in this area. It is part of stage two of this project, funded by the International Park Strategic Partners Group. It builds on an earlier review (completed early in 2002 with funding provided by Parks Victoria) by addressing the health and wellbeing benefits of contact with nature in a parks context, at an individual and community level.

Who says boys don`t read? They do in literature circles!

This article is about Literature Circles and its ongoing implementation at Parade College, where it is regarded as an innovative, flexible and inclusive strategy that motivates adolescent learners, particularly boys, to read for enjoyment, for independent learning, and for the enhancement of literacy knowledge, skills and capabilities.

In dialogue with A.D. Hope: dialogue three: politics and poetics of Australian literature

[Hope was largely responsible for the inclusion of Australian Literature as a separate subject of study in universities. Yet his role in debates on modernism in the Australian context was controversial and he remains one of the main figures who fought for a particular kind of poetry that he saw some modernist methods, experiments, and theories destroying. Dialogue Three aims to hear his side of the story as Hope has become, in many circles, the embodiment of what is euphemistically called ‘the dead white male,’ a title attributed to him long before his actual death in July 2000. Is it the case that Hope’s opposition to ‘free verse’ or his view that men and women know separate metaphysical worldviews or his poetic focus upon European philosophical and literary traditions are sexist, obsolete, or reactionary?
See Dialogue One for details of the following exchange.]