Biological Rhythms, Medication Safety, and Women's Health

Chronotherapy in practice: the perspective of the community pharmacist

BACKGROUND

Optimising the time of drug administration in alignment with circadian rhythms to enhance the clinical effect or minimise/avoid adverse effects is referred to as chronotherapy. Pharmacists have a key role in providing medicine related information, including counselling about the optimal time for medication administration. Where applicable, the principles of chronotherapy should underlie this aspect of medication counselling. Despite significant developments in the science of chronotherapy for specific pharmacological treatments, the perspective of pharmacists about their understanding and application of these principles in practice has not been explored.

OBJECTIVE

To explore community pharmacist's viewpoints about and experience with the application of chronotherapy principles in practice.

SETTING

Community pharmacies within metropolitan Sydney in New South Wales, Australia.

METHODS

Semi-structured, face to face interviews with a convenience sample of community pharmacists were conducted. All interviews were audio-recorded, transcribed verbatim and thematically analyzed using a 'grounded theory' approach, given the novelty of this area. Main outcome measure Community pharmacists' awareness, current practice and future practice support requirements about the principles of chronotherapy.

RESULTS

Twenty-five semi-structured interviews were conducted. Most participants reported encountering cases where clinical decision making about suggesting appropriate times of drug administration to patients was needed. Their approach was mainly pragmatic rather than based on theoretical principles of circadian variation in drug disposition or on current or emerging evidence; thus there was an evidence practice chasm in some cases. However, most participants believed they have an important role to play in counselling patients about optimal administration times and were willing to enact such roles or acquire skills/competence in this area.

CONCLUSION

Community pharmacists contribute to the safe and effective use of medications in providing the patients with information on optimal timing of drug administration during counselling. Further education, practical training and access to information may help pharmacists in translating principles of chronotherapy into the practice.

Need for gender-specific pre-analytical testing: the dark side of the moon in laboratory testing

Many international organisations encourage studies in a sex-gender perspective. However, research with a gender perspective presents a high degree of complexity, and the inclusion of sex-gender variable in experiments presents many methodological questions, the majority of which are still neglected. Overcoming these issues is fundamental to avoid erroneous results. Here, pre-analytical aspects of the research, such as study design, choice of utilised specimens, sample collection and processing, animal models of diseases, and the observer's role, are discussed. Artefacts in this stage of research could affect the predictive value of all analyses. Furthermore, the standardisation of research subjects according to their lifestyles and, if female, to their life phase and menses or oestrous cycle, is urgent to harmonise research worldwide. A sex-gender-specific attention to pre-analytical aspects could produce a decrease in the time for translation from the bench to bedside. Furthermore, sex-gender-specific pre-clinical pharmacological testing will enable adequate assessment of pharmacokinetic and pharmacodynamic actions of drugs and will enable, where appropriate, an adequate gender-specific clinical development plan. Therefore, sex-gender-specific pre-clinical research will increase the gender equity of care and will produce more evidence-based medicine.

Timing is important in medication administration: a timely review of chronotherapy research

BACKGROUND

Chronotherapy involves altering the timing of medication administration to improve the overall control of a disease and to minimise treatment side-effects, and is an emerging concept in the field of therapeutics.

AIM

The aim of this review is to conduct an in-depth analysis of the recent literature in order to identify and evaluate the evidence base for drug chronotherapy.

METHOD

A literature search was conducted in three databases (Medline, Embase, International Pharmaceutical Abstracts) using the search terms "Chronotherapy", "Chronopharmacology", "Chronopharmacokinetics", "Chronopharmacodynamics", "Chronoefficacy", "Chronoformulation", "Morning and Evening", "Morning and Bedtime" and their combinations. The selection criteria for the inclusion of articles in the review included currency (years 2008-Aug 2011), publication in English language, studies done in Humans and non-review articles that pertained to 'drug' therapy.

RESULTS

Our search revealed a total of 192 journal articles, of which 41 articles were selected for review. The specific hypothesis for the effectiveness of chronotherapy that was tested in these 41 studies was chronoeffectiveness (n = 34), followed by chronopharmacokinetics (n = 5), chronomodulation (n = 3) and chronopharmacodynamics (n = 2). The findings from two-thirds (n = 27) of the reviewed studies, support the notion of chronotherapy.

CONCLUSION

The review presents the scope of chronotherapy in drug utilization. We believe that the knowledge of chronotherapy is growing and the current research for chronotherapy is promisingly in the conceptualization or early experimental phase. Going forward, chronotherapy studies should also explore genetic, gender and age related differences. Preliminary screening of new drugs for chronotherapeutic potential may be a way of enhancing quality use of medicines.

Molecular time: an often overlooked dimension to cardiovascular disease

Diurnal rhythms influence cardiovascular physiology such as heart rate and blood pressure and the incidence of adverse cardiac events such as heart attack and stroke. For example, shift workers and patients with sleep disturbances, such as obstructive sleep apnea, have an increased risk of heart attack, stroke, and sudden death. Diurnal variation is also evident at the molecular level, as gene expression in the heart and blood vessels is remarkably different in the day as compared to the night. Much of the evidence presented here indicates that growth and renewal (structural remodeling) are highly dependent on processes that occur during the subjective night. Myocardial metabolism is also dynamic with substrate preference also differing day from night. The risk/benefit ratio of some therapeutic strategies and the appearance of biomarkers also vary across the 24-hour diurnal cycle. Synchrony between external and internal diurnal rhythms and harmony among the molecular rhythms within the cell is essential for normal organ biology. Cell physiology is 4 dimensional; the substrate and enzymatic components of a given metabolic pathway must be present not only in the right compartmental space within the cell but also at the right time. As a corollary, we show disrupting this integral relationship has devastating effects on cardiovascular, renal and possibly other organ systems. Harmony between our biology and our environment is vital to good health.

Gender Differences in Polysomnographic Sleep in Young Healthy Sleepers

Middle-aged and elderly populations exhibit gender differences in polysomnographic (PSG) sleep; however, whether young men and women also show such differences remains unclear. Thirty-one young healthy sleepers (16 men and 15 women, aged 18 to 30 yr, mean+/-SD, 20.5+/-2.4 yr) completed 3 consecutive overnight sessions in a sleep laboratory, after maintaining a stable sleep-wake cycle for 1 wk before study entry. Standard PSG sleep and self-rated sleepiness data were collected each night. Across nights, women showed better sleep quality than men: they fell asleep faster (shorter sleep onset latency) and had better sleep efficiency, with more time asleep and less time awake (all differences showed large effect sizes, d=0.98 to 1.12). By contrast, men were sleepier than women across nights. Both men and women demonstrated poorer overall sleep quality on the first night compared with the subsequent 2 nights of study. We conclude young adult healthy sleepers show robust gender differences in PSG sleep, like older populations, with better sleep quality in women than in men. These results highlight the importance of gender in sleep and circadian rhythm research studies employing young subjects and have broader implications for women's health issues relating to these topics.

Cosinor analysis for temperature time series data of long duration

The application of cosinor models to long time series requires special attention. With increasing length of the time series, the presence of noise and drifts in rhythm parameters from cycle to cycle lead to rapid deterioration of cosinor models. The sensitivity of amplitude and model-fit to the data length is demonstrated for body temperature data from ambulatory menstrual cycling and menopausal women and from ambulatory male swine. It follows that amplitude comparisons between studies cannot be made independent of consideration of the data length. Cosinor analysis may be carried out on serial-sections of the series for improved model-fit and for tracking changes in rhythm parameters. Noise and drift reduction can also be achieved by folding the series onto a single cycle, which leads to substantial gains in the model-fit but lowers the amplitude. Central values of model parameters are negligibly changed by consideration of the autoregressive nature of residuals.