Bioavailability of Oniria®, a Melatonin Prolonged-Release Formulation, Versus Immediate-Release Melatonin in Healthy Volunteers.

BACKGROUND: Melatonin is an endogenous substance which plays a key role in sleep induction by reducing sleep onset latency; it has been approved by the European Food Safety Authority as a food supplement for exogenous administration. Oniria® is a food supplement formulated as 1.98 mg of prolonged-release melatonin tablets; it displays a dual dissolution profile in vitro. OBJECTIVES: The main objective of the present study was to evaluate the relative oral bioavailability of Oniria®, in comparison with immediate-release tablets (IRT) with a similar melatonin content as a reference. We also attempted to characterize the circadian rhythm of endogenous melatonin. METHODS: We performed an open-label, cross-over, randomized, phase I clinical study with two sequences and three periods involving 14 healthy volunteers. We characterized the endogenous melatonin circadian profile (period 1) and pharmacokinetics (PK) of both Oniria® and the reference melatonin (periods 2 and 3). RESULTS: Two phases were clearly differentiated in the PK profile of Oniria®. An initial one, from dosing up to 2 h, and a delayed one from 2 to 11 h post-administration. During the initial phase, both melatonin formulations were equivalent, with a Cmax value close to 4000 pg/mL. However, in the delayed phase, Oniria® showed significantly higher melatonin concentrations than the IRT (three times higher at 4-6 h post-administration). Moreover, Oniria® exhibited concentrations above the endogenous melatonin peak of 80 pg/mL for up to 2.5 h versus the reference formulation, potentially suggesting an effect of Oniria®, not only in the induction of sleep, but also in the maintenance. CONCLUSION: Oniria® could be a highly promising food supplement, not only for sleep induction but also for the maintenance of sleep.

Benefits of the application of heat and pressure on peripheral venous cannulation in adults: A randomized controlled trial.

AIM: To evaluate the effectiveness of the application of topical heat, high pressure or a combination of both on antebrachial venous cannulation. DESIGN: A cross-over clinical trial blinded for haemolysis analysis. METHODS: This cross-over clinical trial with two periods was performed in the Clinical Trial Unit of Hospital Universitario de La Princesa (Madrid) during June-July of 2017 in 59 healthy adults who were randomly allocated to one of three interventions: (1) Using dry topical heat for 7 min produced by two hot seed bags (N = 21), (2) Applying controlled pressure from a sphygmomanometer inflated to 100 mmHg (N = 18) and (3) combining heat and pressure (N = 20) in one period out of two. All interventions were contrasted to standard clinical practice in the other period. The comparator involved a standard tourniquet around the upper arm to restrict venous blood flow. The primary outcome was effectiveness measured as vein cannulation at first attempt. Secondary outcomes were vein perception, pain, haemolysis in blood samples and adverse events. RESULTS: All the interventions were more effective than comparator. Vein perception was optimized in about all individuals. Moreover, pain relief was significantly higher when high pressure was applied. Haemolysis was not affected in any of the three interventions. In addition, no serious adverse events appeared. CONCLUSION: High pressure is determined to be the most effective in vein catheterization, pain relief, vein perception and quality of blood sample inalterability. Moreover, it is safe considering that only one adverse event appeared. IMPACT: Vein cannulation is a very common invasive technique, where repeated failures have been registered. Thus, we consider it relevant to develop interventions to achieve venous catheterization at first attempt to alleviate the pain and anxiety associated with this technique. We advocate using high pressure intervention for emergency, due to swiftest method and feasible in case of lacking resources, such as sphygmomanometers in the ambulance. Interventions can be extrapolated to healthy young adults, adults and patients who have healthy vein status perception. Pressure intervention could be an alternative to heat intervention when performing vein cannulation due to its lower risk of transient paresthesia for older people who often suffer from arterial hypertension.

The effects of aripiprazole and olanzapine on pupillary light reflex and its relationship with pharmacogenetics in a randomized multiple-dose trial.

AIMS: Pupillography is a noninvasive and cost-effective method to determine autonomic nerve activity. Genetic variants in cytochrome P450 (CYP), dopamine receptor (DRD2, DRD3), serotonin receptor (HTR2A, HTR2C) and ATP-binding cassette subfamily B (ABCB1) genes, among others, were previously associated with the pharmacokinetics and pharmacodynamics of antipsychotic drugs. Our aim was to evaluate the effects of aripiprazole and olanzapine on pupillary light reflex related to pharmacogenetics. METHODS: Twenty-four healthy volunteers receiving 5 oral doses of 10 mg aripiprazole and 5 mg olanzapine tablets were genotyped for 46 polymorphisms by quantitative polymerase chain reaction. Pupil examination was performed by automated pupillometry. Aripiprazole, dehydro-aripiprazole and olanzapine plasma concentrations were measured by high-performance liquid chromatography-tandem mass spectrometry. RESULTS: Aripiprazole affected pupil contraction: it caused dilatation after the administration of the first dose, then caused constriction after each dosing. It induced changes in all pupillometric parameters (P < .05). Olanzapine only altered minimum pupil size (P = .046). Polymorphisms in CYP3A, HTR2A, UGT1A1, DRD2 and ABCB1 affected pupil size, the time of onset of constriction, pupil recovery and constriction velocity. Aripiprazole, dehydro-aripiprazole and olanzapine pharmacokinetics were significantly affected by polymorphisms in CYP2D6, CYP3A, CYP1A2, ABCB1 and UGT1A1 genes. CONCLUSIONS: In conclusion, aripiprazole and its main metabolite, dehydro-aripiprazole altered pupil contraction, but olanzapine did not have such an effect. Many polymorphisms may influence pupillometric parameters and several polymorphisms had an effect on aripiprazole, dehydro-aripiprazole and olanzapine pharmacokinetics. Pupillography could be a useful tool for the determination of autonomic nerve activity during antipsychotic treatment.