The changing outlook of psychedelic drugs: The importance of risk assessment and occupational exposure limits

Serotonergic psychedelics, such as lysergic acid diethylamide (LSD), psilocybin, dimethyltryptamine (DMT), and 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), are currently being investigated for the treatment of psychiatric disorders such as depression and anxiety. Clinical trials with psilocybin and LSD have shown improvement in emotional and psychological scores. Although these drugs are reported to be safe in a controlled environment (such as clinical trials), exposure to low doses of these drugs can result in psychedelic effects, and therefore, occupational safety is an important consideration to prevent adverse effects in the workplace from low daily exposure. This article will discuss the factors involved in the derivation of occupational exposure limits (OELs) and risk assessment of these psychedelic drugs. To support the OEL derivations of psychedelic drugs, information regarding their mechanism of action, adverse effect profiles, pharmacokinetics, clinical effects, and nonclinical toxicity were considered. Additionally, psilocybin and LSD, which are the most extensively researched psychedelic substances, are employed as illustrative examples in case studies. The OELs derived for psilocybin and for LSD are 0.05 and 0.002 μg/m3 , respectively, which indicates that these are highly hazardous compounds, and it is important to take into account suitable safety measures and risk-management strategies in order to minimize workplace exposure.

1052 Continuous Blood Pressure Monitoring In Sleep

Introduction

Abnormal nocturnal blood pressure(BP) such as non-dipping or nocturnal hypertension(reverse-dipping) represents a potent marker for cardiovascular risks. Standard cuff-based ambulatory nocturnal BP measurement yields limited data points potentially resulting in imprecise results, especially compared to continuously recorded BP. We hypothesized nocturnal BP based on periodic measurement would be different from true average beat-to-beat based BP.

Methods

We prospectively enrolled patients undergoing clinically indicated in-lab polysomnography, both CPAP and non-CPAP studies, for sleep apnea evaluation. Nocturnal BP was continuously monitored beat-to-beat by a noninvasive Caretaker™ device, which uses the Pulse Decomposition Analysis(PDA) algorithm. We compared BP recorded at 30-minute intervals with average BP continuously recorded over 30 minutes, both recorded by Caretaker™. We also looked at the differences between recording spot and continuous BP from an awake or sleeping state and BP variability(SD) based on continuously recorded BP. Using first 30 min as a reference, we determined dipping status (dipping: 10-20% reduction, level: 0-10% reduction, riser: any increase) by the two methods.

Results

A total of 18 patients were recruited(male:11, mean age:52.2). Among a total of 261 periodic BP measurements, 60 (30.0%) were obtained while awake. Mean nocturnal SBP by periodic BP measurement was higher compared with beat-to-beat-derived average BP(135.6mmHg[24.2] vs. 131.5[20.3], p<0.0001). The difference between the two methods remained similar when continuous BP was derived from sleep vs. awake period(4.5mmHg[3.1] vs. 7.7[9.9], p=0.202). BP variability was more pronounced during awake compared with sleep period(6.7mmHg[8.1] versus 3.95[7.5], p=0.047). 8 patients were dippers by spot check measurement, but 11 were dippers by continuous BP.

Conclusion

Standard ambulatory periodic nocturnal BP recording may not yield true sleep BP patterns due to its spot-check nature and lack of sleep-awake information, which leads to inaccurate dipping measurements. Incorporation of beat-to-beat continuous BP measurement can provide more accurate and meaningful nocturnal BP information.

Support

N/A

Treatment of primary aldosteronism is associated with a reduction in the severity of obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is known to commonly co-exist with primary aldosteronism (PA), but it is unknown if treatment of PA improves sleep apnoea parameters in these patients. We therefore aimed to determine whether specific medical or surgical treatment of PA improves OSA, as measured by the apnoea-hypopnoea index (AHI). We recruited patients undergoing diagnostic workup for PA if they had symptoms suggestive of OSA. Patients with confirmed PA underwent polysomnography (PSG) at baseline and again at least 3 months after specific treatment for PA. Of 34 patients with PA, 7 (21%) had no evidence of OSA (AHI <5), 9 (26%) had mild (AHI ⩾5 and <15), 8 (24%) moderate (AHI ⩾15 and <30) and 10 (29%) severe OSA (AHI ⩾30). Body mass index tertile, neck circumference and 24 h urinary sodium correlated with the AHI. Twenty patients had repeat PSG performed after treatment for PA (mineralocorticoid receptor antagonists in 13 with bilateral PA and adrenalectomy in 7 with unilateral PA). In this group the median (s.d.) AHI reduced from 22.5 (14.7) to 12.3 (12.1) (P=0.02). Neck circumference reduced with PA treatment (41.6 vs 41.2 cm, P=0.012). OSA is common in patients with primary aldosteronism and may improve with specific therapy for this disease. Aldosterone and sodium-mediated fluid retention in the upper airways and neck region may be a potential mechanism for this relationship.

Potential interactions among disease, pesticides, water quality and adjacent land cover in amphibian habitats in the United States

To investigate interactions among disease, pesticides, water quality, and adjacent land cover, we collected samples of water, sediment, and frog tissue from 21 sites in 7 States in the United States (US) representing a variety of amphibian habitats. All samples were analyzed for >90 pesticides and pesticide degradates, and water and frogs were screened for the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) using molecular methods. Pesticides and pesticide degradates were detected frequently in frog breeding habitats (water and sediment) as well as in frog tissue. Fungicides occurred more frequently in water, sediment, and tissue than was expected based upon their limited use relative to herbicides or insecticides. Pesticide occurrence in water or sediment was not a strong predictor of occurrence in tissue, but pesticide concentrations in tissue were correlated positively to agricultural and urban land, and negatively to forested land in 2-km buffers around the sites. Bd was detected in water at 45% of sites, and on 34% of swabbed frogs. Bd detections in water were not associated with differences in land use around sites, but sites with detections had colder water. Frogs that tested positive for Bd were associated with sites that had higher total fungicide concentrations in water and sediment, but lower insecticide concentrations in sediments relative to frogs that were Bd negative. Bd concentrations on frog swabs were positively correlated to dissolved organic carbon, and total nitrogen and phosphorus, and negatively correlated to pH and water temperature. Data were collected from a range of locations and amphibian habitats and represent some of the first field-collected information aimed at understanding the interactions between pesticides, land use, and amphibian disease. These interactions are of particular interest to conservation efforts as many amphibians live in altered habitats and may depend on wetlands embedded in these landscapes to survive.

Parkinson's disease, CYP2D6 polymorphism, and age

OBJECTIVE

PD may be caused by genetic susceptibility to neurotoxins. CYP2D6 is a candidate gene for PD because it regulates drug and toxin metabolism, but association studies have been inconsistent. The aim of this study was to test if the CYP2D6*4 allele (poor metabolizer phenotype) is associated with earlier age at onset.

METHODS

Five hundred seventy-six patients with PD and 247 subjects without PD were studied using standard diagnostic, genotyping, and statistical techniques.

RESULTS

Surprisingly, mean onset age was significantly later in *4-positive patients. Frequency of *4 was significantly higher in late-onset PD than early-onset PD. When early- and late-onset PD were analyzed separately, *4 had no effect on onset age; hence, the association with delayed onset was likely an artifact of an elevated *4 frequency in late-onset PD. Contrary to a common assumption that CYP2D6 frequencies do not change with age, *4 frequency rose significantly with advancing age, both in patients with PD (from 0.16 at mean age of 56.5 years to 0.21 at mean age of 72) and subjects without PD (from 0.09 at mean age of 45.5 years to 0.21 at mean age of 72). *4 Frequencies in patients with early- and late-onset PD, although different from each other, were in agreement with similarly aged subjects without PD, suggesting the elevated *4 frequency in late-onset PD was likely an age effect, unrelated to PD.

CONCLUSION

The CYP2D6*4 allele is not associated with earlier PD onset. *4 May be associated with survival. Inconsistent results from allelic association studies may have been due to an unrecognized age effect.

Physical exercise in essential hypertension

Although several studies have shown that physical training lowers blood pressure values both in normotensives and in hypertensives, the mechanisms accounted for this effect are not clearly elucidated. It has been reported that the decrease in blood pressure and heart rate that accompanies physical training is associated not only with an increase in vagal tone but also with a reduction in plasma norepinephrine levels. Whether this reduction really means a decrease in sympathetic neural discharge is unknown, however. To clarify this issue, we have performed in 7 normotensives direct recording of postganglionic muscle sympathetic nerve activity from the peroneal nerve by microneurography before and after 10 weeks of an endurance training which increased oxygen consumption by 10%. It was shown that the blood pressure lowering effect of the training program was accompanied by a marked reduction in resting sympathetic nerve activity. These data provide the first direct evidence that in man, the blood pressure reduction induced by physical training is mediated by the neural sympathetic mechanisms.

Intracranial calcification in hyperparathyroidism associated with gait apraxia and parkinsonism

Two patients with hyperparathyroidism had symmetric calcification of the brain, including the basal ganglia. In both patients, the neurologic disorder included parkinsonism and gait apraxia. Computerized tomography may help define the prevalence and clinical manifestations of this rare syndrome.