Titre : | A theory of benzodiazepine dependence that can explain whether flumazenil will enhance or reverse the phenomena (1990) |
Titre traduit : | (Une théorie de la dépendance aux benzodiazepines qui peut expliquer si le flumazenil doit augmenter ou diminuer le phénomène) |
Auteurs : | S. E. FILE ; P. K. HITCHCOTT |
Type de document : | Article : Périodique |
Dans : | Psychopharmacology (Vol.101, n°4, August 1990) |
Article en page(s) : | 525-532 |
Langues: | Anglais |
Discipline : | TRA (Traitement et prise en charge / Treatment and care) |
Mots-clés : |
Thésaurus mots-clés BENZODIAZEPINES ; SEVRAGE ; ACCOUTUMANCE ; ANTAGONISTE ; MODELE ANIMAL |
Résumé : |
FRANÇAIS :
Observation des effets bidirectionnels du flumazénil, antagoniste des benzodiazépines (BDZs), chez des animaux dépendants. Lors du sevrage, selon le niveau d'anxiété de l'animal, le flumazénil est anxiolytique ou anxiogène. Les auteurs proposent une théorie fondée sur l'hypothèse de la normalisation par le flumazénil des récepteurs des BDZs à un seuil de base. Dans le développement de la dépendance, deux mécanismes biochimiques indépendants interviendraient, l'un sur l'apparition de la tolérance aux réponses anxiolytiques, l'autre sur l'augmentation de l'anxiété lors du sevrage. L'administration de flumazénil entrainerait des modifications sur ce deuxième mécanisme. ENGLISH: Repeated administration of benzodiazepines (BDZs) produces dependence in man and animals and this is reflected in the phenomena of tolerance and withdrawal responses. In BDZ-dependent animals the BDZ-receptor antagonist flumazenil (Ro 15-1788) reverses the increased anxiety and decreased seizure threshold seen when benzodiazepine treatment is withdrawn. In contrast are reports that flumazenil enhances BDZ-withdrawal responses. Indirect influences on the direction of flumazenil's effects on anxiety are the duration and dose of BDZ treatment, whether tolerance has developed to its anxiolytic effect and whether there is an anxiogenic response on drug withdrawal. However, we conclude that the crucial factor is the anxiety level of the animal: when this is high flumazenil becomes anxiolytic; when this is low flumazenil is anxiogenic. These bidirectional effects of flumazenil can be seen in drug-naive and BDZ-dependent animals. We propose a theory of benzodiazepine dependence that can account for anxiogenic responses on drug withdrawal and for flumazenil's bidirectional effects; central to this theory is the assumption that flumazenil normalises the benzodiazepine receptor, returning it to a baseline state. Thus it is whether an animal's score lies above or below this baseline that will determine the direction of flumazenil's effect. The clinical implications of this theory are discussed. We suggest that during the development of benzodiazepine dependence, two independent adaptive biochemical mechanisms are triggered: one underlying the development of tolerance to the anxiolytic responses, the other underlying the incidence of increased anxiety on drug withdrawal. It is only changes in the latter that are induced by the administration of flumazenil. |
Domaine : | Drogues illicites / Illicit drugs |
Refs biblio. : | 42 |
Affiliation : |
Psychopharmacol. Res. Unit, UMDS, Div Pharmacol., Univ. London, Guy's Hosp., London SE1 9RT Royaume-Uni. United Kingdom. |
Numéro Toxibase : | 201276 |
Centre Emetteur : | 02 Coordonnateur |
Accueil