Le diagnostic rapide des mécanismes de résistance aux antibiotiques

Rapid tests using immunologic, biochemical or molecular biology techniques have been introduced for routine diagnosis in the laboratories of microbiology. The development of rapid tests for the detection of antimicrobial resistance mechanisms is justified in patients with high mortality risk when the antimicrobial therapy is unadapted. Rapid tests for detection of beta-lactamase and methicillin-resistance in staphylococci are available for routine use. The development of new molecular techniques for identification coupled with the detection of resistance genes should allow to widely expand the number of resistance mechanisms screened for.     

Toxicité sérotoninergique résultant d’une interaction médicamenteuse entre le bleu de méthylène et les inhibiteurs de la recapture de la sérotonine

Background:

Methylene blue is used in medical practice for various reasons. Recent findings point to a potential interaction with serotonin reuptake inhibitors (SRIs) that could lead to serotonergic toxicity.

Objective:

To describe the risk of serotonergic toxicity associated with the interaction between methylene blue and SRIs.

Data sources:

Relevant publications were searched systematically via MEDLINE (1946 to March 21, 2013) and Embase (1974 to 2013, week 11) with the following search terms: “methylene blue”, “methylthioninium”, “monoamine oxidase inhibitors”, “serotonin reup-take inhibitors”, and “serotonin syndrome”. No restrictions were applied in relation to the indication for methylene blue or the language of publication. The reference lists of identified articles were also searched.

Study selection and data extraction:

Eighteen case reports and 2 case series were identified for inclusion. To date, no randomized controlled trials have been published.

Data synthesis:

The first case report indicating suspicion of an interaction between methylene blue and SRIs was published in 2003. Seventeen other case reports describing the same type of interaction have been published since then. The 2 case series provided data from about 325 parathyroidectomies in which methylene blue was used for staining. The 17 patients who experienced central nervous system toxicity were all taking SRIs in the preoperative period.

Conclusion:

When administered in combination with SRIs, methylene blue may lead to serotonergic toxicity at doses as low as 0.7 mg/kg. Methylene blue would seem to have monoamine oxidase A inhibitory properties. Precautions should be taken to avoid this interaction.[Publisher’s translation]     

Etude psychométrique des effets de l'amobarbital (amytal) et de la chlorpromazine sur des sujets normaux

Summary The authors sought to develop knowledge of the characteristics of different types of psycholeptic drugs. Using 18 normal voluntary subjects, and psychometric methods, the authors experimentally compared the effects of the following: a dose of 100 mg of chlorpromazine (neuroleptic), a dose of 300 mg of amobarbital (hypnotic) and a placebo.The psychophysiological measures and intelligence tests showed that with the 2 drugs there was a particulary noticeable deficit in the most elementary of sensori-motor functions but only a negligible deficit of intellectual functions. On the other hand with the personality test used (MMPI), it was found that chlorpromazine had practically no effect whereas amobarbital brought about limited but distinct changes in the profile and particularly on the Ma, Sc and Mf scales. It is not possible to interpret precisely such modifications in the responses of subjects asked to describe their feelings and behaviour.