Timing treatment to the rhythm of disease. A short course in chronotherapeutics

Development of a conceptual model for research on cyclical variation of patient reported outcome measurements (PROMs) in patients with chronic conditions: a scoping review

BACKGROUND

Although circadian, seasonal, and other cycles have been observed for a number of chronic conditions, their impact on patient reported outcomes measurements (PROMs) has not been systematically explored, rendering our understanding of the effect of time of measurement on PROM scores very limited. The aim was to conduct a scoping review to determine what is known about how intra-individual cyclical variation might affect the way individuals with chronic conditions respond to patient-reported outcome measures.

METHODS

A protocol of a systematic scoping review was registered on PROSPERO (CRD42017058365). We developed a search strategy based on previous relevant reviews and implemented it in: MEDLINE, Embase, PsycINFO, and CINAHL. No restrictions were placed on article types and backward and forward citation searches were conducted. Screening and data extraction were independently completed by up to four reviewers. An adapted version of CASP criteria was used to appraise the quality of included articles. Concepts that were important in understanding the impact of cyclical variation on PROM scores were elicited from the papers and iteratively refined through discussion amongst the authors.

RESULTS

2420 references resulted from the searches, with 33 articles meeting the inclusion criteria. Most study designs included observational research (particularly ecological momentary assessment), 2 were RCTs and 2 were systematic reviews. Studies mainly focused on specific health conditions: mental health, respiratory and musculoskeletal. There was a lack of qualitative research and theoretical framework to explore these concepts more fully. Five overarching concepts emerged: variation in outcomes, variation of scores, psychological status, individual factors, and environmental/situational factors. A conceptual model was developed outlining the relationships between these concepts.

CONCLUSIONS

There is empirical evidence that supports cyclical variation in PROM scores across different chronic conditions, with potential very significant implications for administration and interpretation of PROMs. The proposed conceptual model can support further research in this area.

Peripheral immune circadian variation, synchronisation and possible dysrhythmia in established type 1 diabetes

AIMS/HYPOTHESIS

The circadian clock influences both diabetes and immunity. Our goal in this study was to characterise more thoroughly the circadian patterns of immune cell populations and cytokines that are particularly relevant to the immune pathology of type 1 diabetes and thus fill in a current gap in our understanding of this disease.

METHODS

Ten individuals with established type 1 diabetes (mean disease duration 11 years, age 18-40 years, six female) participated in a circadian sampling protocol, each providing six blood samples over a 24 h period.

RESULTS

Daily ranges of population frequencies were sometimes large and possibly clinically significant. Several immune populations, such as dendritic cells, CD4 and CD8 T cells and their effector memory subpopulations, CD4 regulatory T cells, B cells and cytokine IL-6, exhibited statistically significant circadian rhythmicity. In a comparison with historical healthy control individuals, but using shipped samples, we observed that participants with type 1 diabetes had statistically significant phase shifts occurring in the time of peak occurrence of B cells (+4.8 h), CD4 and CD8 T cells (~ +5 h) and their naive and effector memory subsets (~ +3.3 to +4.5 h), and regulatory T cells (+4.1 h). An independent streptozotocin murine experiment confirmed the phase shifting of CD8 T cells and suggests that circadian dysrhythmia in type 1 diabetes might be an effect and not a cause of the disease.

CONCLUSIONS/INTERPRETATION

Future efforts investigating this newly described aspect of type 1 diabetes in human participants are warranted. Peripheral immune populations should be measured near the same time of day in order to reduce circadian-related variation.

Clinical Aspects of Human Circadian Rhythms

Circadian rhythmicity can be important in the pathophysiology, diagnosis, and treatment of clinical disease. Due to the difficulties in conducting the necessary experimental work, it remains unknown whether ~24-h changes in pathophysiology or symptoms of many diseases are causally linked to endogenous circadian rhythms or to other diurnal factors that change across the day, such as changes in posture, activity, sleep or wake state, or metabolic changes associated with feeding or fasting. Until the physiology is accurately known, appropriate treatment cannot be designed. This review includes an overview of clinical disorders that are caused or affected by circadian or diurnal rhythms. The clinical side effects of disruption of circadian rhythmicity, such as in shiftwork, including the public health implications of the disrupted alertness and performance, are also discussed.

Design and optimization of colon-targeted system of theophylline for chronotherapy of nocturnal asthma

The objective of the present work was to develop a delayed-onset controlled-release colon-targeted system of theophylline, and to achieve the chronotherapy of nocturnal asthma. The formulation consisted of a core tablet containing hydroxypropyl methylcellulose used for achieving controlled release of drug, and a Eudragit S100:ethyl cellulose (EC) coating capable of delaying the drug release. The system was optimized using a 3(2) full factorial design, wherein two factors [ratio of Eudragit S100:EC and the coating level (% w/w)] were evaluated for lag time, t(50) and t(80) . The optimum formulation consisted of Eudragit S100:EC in a 60:40 ratio and a coating level of 7.5% (w/w). Results showed that the tablets prepared according to the optimized values released no drug in the upper part of gastrointestinal tract; drug release was initiated at pH 6.4 (colon) after a lag time of 5 h. In vivo evaluation (pharmacokinetic studies and roentgenography) in rabbits revealed that the tablet remained intact until it reaches the colon and the drug release was initiated after a lag time of 5 h. Thus, it can be concluded that the developed system exhibited a promising colonic targeting and hence may be used for chronotherapy of nocturnal asthma.

Drug delivery technologies for chronotherapeutic applications

It has been proven that the body follows a 24-hour cycle called a circadian rhythm. This cycle is coordinated by the suprachiasmatic nucleus and controls nearly all bodily functions including those related to drug delivery. Knowledge of the body's circadian rhythm leads to an improved understanding of diseases and their treatment, known as chronotherapy, such that synchronizing drug application in accordance with the natural rhythm of the body leads to improved disease management and a greater patient therapeutic outcome. Chronotherapeutic diseases include asthma, cardiovascular diseases, glaucoma, rheumatoid arthritis and cancers. In order to treat these diseases numerous chronotherapeutic drug delivery systems have been developed, such that drug is released in the period when it is most needed. This review paper attempts to concisely explicate the role of circadian rhythms in various disease states and furthermore describes the various oral drug delivery technologies that have been employed for the treatment of chronotherapeutic diseases.

Hemodialysis timing, survival, and cardiovascular outcomes in the Hemodialysis (HEMO) Study

BACKGROUND

The timing of medical therapies has been shown to influence the outcomes and side effects of treatments for disease. This report examines the extent to which hemodialysis treatment time of day was associated with cardiovascular mortality and morbidity and all-cause mortality in a secondary analysis of the Hemodialysis Study.

METHODS

Dialysis start time defined dialysis shift: morning beginning between 0400 and 0930 hours (n = 822); midday, between 0930 and 1530 hours (n = 851); and evening, between 1530 and 2200 hours (n = 172). Outcome measures included all-cause mortality, cardiac death, composite end point of all-cause mortality or first cardiac hospitalization, and composite end point of first cardiac hospitalization or cardiac death.

RESULTS

Morning hemodialysis was associated with a lower likelihood of cardiovascular events compared with the evening shift in all-cause mortality or first cardiac hospitalization (evening versus morning, relative risk [RR], 1.29; 95% confidence interval [CI], 1.01 to 1.65; P = 0.043), as well as first cardiac hospitalization or cardiac death (evening versus morning, RR, 1.44; 95% CI, 1.11 to 1.89; P = 0.007). No differences were noted in the other 2 outcomes, and there was no statistically significant difference between the morning and midday shifts. Although crude mortality rates were greater in the midday compared with morning (RR, 1.21; 95% CI, 1.05 to 1.39; P = 0.008), this association was attenuated after adjustment (RR, 1.04; 95% CI, 0.89 to 1.22; P = 0.64).

CONCLUSION

Making extensive adjustment for patient characteristics, this report does not support the association of lower all-cause mortality with morning hemodialysis or a particular benefit for older patients.

Modulated release metoprolol succinate formulation based on ionic interactions: In vivo proof of concept

A modulated release, multiunit oral drug delivery technology using a system based on ionic interactions of anions of salts with quaternary ammonium ions of the ammoniomethacrylate polymer is described. The system consisted of a drug layered, EUDRAGIT NE-coated salt core which was further coated with EUDRAGIT RS. The relative effects of different anions on the polymer permeability have been investigated by studying their influence on the in vitro drug release. A prototype formulation of metoprolol succinate using this technology was developed and the drug release from the formulation was adjusted to have a release profile which would match the circadian rhythm i.e. a higher amount of drug would be available after an initial lower release (accelerated type of release). The formulation was tested in vivo in 12 healthy human volunteers in an open label, randomized, two-treatment, two-period, single dose crossover bio-study with reference formulation Beloc-zok. The in vivo release demonstrated that compared to the reference, a higher amount of drug was available in the plasma from the 7th hour onwards. A higher AUC of the drug was also observed compared to the reference formulation. An in vitro-in vivo correlation was attempted to identify a bio-relevant in vitro dissolution medium for the formulation.

The normal circadian pattern of blood pressure: implications for treatment

Blood pressure fluctuates over 24 h following a circadian rhythm that reaches a peak in the morning shortly after awakening. The onset of many acute cardiovascular and cerebrovascular events shows a synchronous cyclical pattern, with the highest incidence of morbidity and mortality in the early morning hours. Strong, although circumstantial, evidence suggests that the early morning surge in blood pressure may contribute to the onset of acute cardiovascular episodes. Sustained blood pressure control that blunts the early morning blood pressure surge may help to reduce the incidence of these events. Antihypertensive agents are needed that provide smooth and sustained blood pressure control for the full 24 h, including the risky early morning hours. The angiotensin II receptor blocker telmisartan given once daily, because of its long half-life and mechanism of action, is likely to confer benefit in terms of 24-h blood pressure control and may reduce cardiovascular risk at the time of greatest patient vulnerability.

Morning versus evening dosing of desloratadine in seasonal allergic rhinitis: a randomized controlled study [ISRCTN23032971]

BACKGROUND: A circadian rhythm of symptoms has been reported in allergic rhinitis and some studies have shown the dosing time of antihistamines to be of importance for optimizing symptom relief in this disease. The objective of this study was to examine the efficacy of morning vs. evening dosing of the antihistamine desloratadine at different time points during the day. METHODS: Patients >/= 18 years, with seasonal allergic rhinitis received desloratadine 5 mg orally once daily in the morning (AM-group) or evening (PM-group) for two weeks. Rhinorrhea, nasal congestion, sneezing and eye symptoms were scored morning and evening. Wilcoxon rank sum and 2-way ANOVA test were used. RESULTS: Six-hundred and sixty-three patients were randomized; 336 in the AM-group; 327 in the PM-group. No statistically significant differences were seen between the AM and PM group at any time points. In the sub-groups with higher morning or evening total symptom score no difference in treatment efficacy was seen whether the dose was taken 12 or 24 hours before the higher score time. There was a circadian variation in baseline total symptom score; highest during daytime and lowest at night. The circadian variation in symptoms was reduced during treatment. This reduction was highest for daytime symptoms. CONCLUSIONS: A circadian rhythm was seen for most symptoms being more pronounced during daytime. This was less apparent after treatment with desloratadine. No statistically significant difference in efficacy was seen whether desloratadine was given in the morning or in the evening. This gives the patients more flexibility in choosing dosing time.

Benefits of different drug formulations in psychopharmacology

Adequate dosage forms are essential for achieving successful pharmacotherapy. Innovative dosage forms or delivery systems may direct a drug to its specific site of action, optimize the timing of the drug release, or increase comfort or convenience for the patient. Thus, such innovations may improve efficacy and tolerability and lead to improvements in health-related quality of life. Specialized dosage forms (e.g., depot injections, extended-release formulations) of several psychiatric agents have been extensively used. The latest addition is an orally disintegrating formulation of the antidepressant mirtazapine. This dosage form dissolves rapidly in the mouth and is convenient for the large proportion of patients who have difficulty in swallowing tablets.