Long-acting and short-acting benzodiazepines in the elderly: kinetic differences and clinical relevance

Clinically Significant Drug Interactions Between Psychotropic Agents and Repurposed COVID-19 Therapies

As many patients with underlying psychiatric disorders may be infected with COVID-19, and COVID-19-affected subjects may frequently experience a new onset of psychiatric manifestations, concomitant use of psychotropic medications and COVID-19 therapies is expected to be highly likely and raises concerns of clinically relevant drug interactions. In this setting, four major mechanisms responsible for drug interactions involving psychotropic agents and COVID-19 therapies may be identified: (1) pharmacokinetic drug-drug interactions mainly acting on cytochrome P450; (2) pharmacodynamic drug-drug interactions resulting in additive or synergistic toxicity; (3) drug-disease interactions according to stage and severity of the disease; and (4) pharmacogenetic issues associated with polymorphisms of cytochrome P450 isoenzymes. In this review, we summarise the available literature on relevant drug interactions between psychotropic agents and COVID-19 therapies, providing practical clinical recommendations and potential management strategies according to severity of illness and clinical scenario.

A double-blind comparison of two lormetazepam doses in elderly insomniacs

The relative efficacy and tolerability of two lormetazepam doses, 0.5 mg and 1.0 mg, were compared in 145 elderly insomniacs in a double-blind, multi-centre study. On entry, data were recorded on the patient characteristics and sleep pattern, and patients were allocated at random to receive treatment with either 0.5 mg or 1.0 lormetazepam per night for 7 nights. Details were recorded daily in a diary by patients on sleep latency, the number of night-time awakenings, time of morning awakening, and whether they awoke refreshed. A record was also kept of any adverse effects of treatment. At the end of the study period, an overall assessment was made by the physician of the patients' response to treatment. The results showed that patients in both dose groups improved significantly (p = 0.001) in the three principal efficacy measures, but there were no apparent trends in the time when patients awakened in the morning. The only evidence of a difference in response to the two doses was that significantly (p less than 0.01) more patients on the larger dose were given a global rating of 'much improved' by the physician. Five patients withdrew from the study; 2 because of lack of efficacy, 2 because of side-effects, and 1 because of a suspected myocardial infarction not related to therapy. Only 6% of patients (4 on each dosage) reported adverse effects, most frequently related to carry-over sedation, i.e. drowsiness, sleepiness, muzzy head. (ABSTRACT TRUNCATED AT 250 WORDS)

Toxic effects of chemicals: difficulties in extrapolating data from animals to man

This review attempts an analysis of the major components which make it extremely difficult to extrapolate toxicological data obtained with chemicals from animals to man. A first problem concerns the use of doses to express the unit of comparison across animal species; the dose is a parameter exogenous to the body and when a chemical enters the body concentrations should be utilized. There is in fact evidence that for several chemicals equal doses in different animal species do not mean equal concentrations in blood or tissues. Concentrations of chemicals should be measured for extrapolation purposes as close as possible to the site of the toxic effect. A second problem regards the fact that several chemical are transformed in the body into other chemical species--sometimes few and sometimes many--and some of these species (active metabolites) display biological activity in some cases higher than different from or antagonistic to those of the parent compounds. Some of these metabolites are highly reactive and therefore bind to body components, particularly macromolecules such as proteins and nucleic acids. There is evidence that metabolism is quantitatively and/or qualitatively different in various animal species. A third problem concerns the difference in various animal species in the biological substrates on which chemicals exert their toxic effects. Equal concentrations of chemicals and their metabolites do not mean equal toxic effects across animal species because endogenous metabolic processes, cell permeability, enzymes, and receptors are not necessarily the same in animals and man. To overcome these difficulties there is a need for closer integration of different disciplines in the toxicological evaluation of chemicals. A scientific rather than a routine approach in toxicology is emphasized.