Rôle du Cotrimoxazole dans la variabilité pharmacologique d'Atazanavir et les modifications du microbiote intestinal

Cotrimoxazole, sulfamethoxazole-trimethoprim (SMX-TMP), is an antibiotic used in HIV-infected patients in prophylaxis for the prevention of opportunistic infections. We have previously shown with an ex-vivo method using Ussing chambers that in rats, treatment with SMX-TMP resulted in a decrease in colonic absorption of atazanavir (ATV), an inhibitor of protease of HIV-1. The work presented in this thesis aims to: 1. determine in rats the in vivo effect of SMX-TMP treatment on the pharmacokinetics of ATV and changes in the gut microbiota. 2. analyze in human the effect of SMX-TMP treatment on the ATV trough plasma concentrations using a retrospective study of clinical and pharmacological data (Dat'AIDS) and international pharmacovigilance data from WHO (VigiBase). In rats, treatment with SMX-TMP significantly increased the pharmacokinetic parameters of ATV (AUC0-8h: 27201.6±4278.8 vs 2308.7±505.5 ng.mL-1.h, p=0.001) and decreased Enterobacteriaceae (3.9±0.2 log10 vs 7.6±0.2 log10 16S rRNA copies, p <0.01) in the caecal microbiota. Other bacterial groups as well as total bacteria were not modified. At the same time, a significant increase in total intestinal transit time was observed. In human, there was no significant difference in the proportion of patients who achieved the threshold of toxicity of ATV trough plasma concentrations between treated with SMX-TMP compared to the control group, adjusted odds ratio (OR) = 1.4 (95% CI: 0. 5-4.4). Regarding the pharmacovigilance data, the proportion of patients treated concomitantly with SMX-TMP and ATV who had hyperbilirubinemia, which is indicative of a rise in the ATV trough plasma concentrations, was not significantly different from that of patients treated with ATV alone, adjusted OR = 0.9 (95% CI: 0.6-1.2). In conclusion, the ex vivo results observed in the rat are not supported by the observed in vivo results in the whole animal. The increase in the pharmacokinetic parameters of ATV could be the consequence of the lengthening of the gastrointestinal transit time which would be due to a decrease in serotonin synthesis, following the modification of the gut microbiota as described by some authors. This increase in pharmacokinetic parameters is not observed in human. This apparent lack of effect reinforces the current strategy for using SMX-TMP in the prevention of opportunistic infections in HIV-infected patients treated with ATV.Le cotrimoxazole, sulfaméthoxazole-triméthoprime (SMX-TMP), est un antibiotique utilisé chez les patients infectés par le VIH en prophylaxie pour prévenir la survenue des infections opportunistes. Nous avons précédemment montré par une méthode ex-vivo utilisant les chambres d'Ussing que chez le rat, un traitement par le SMX-TMP entraînait au niveau du côlon une diminution de l'absorption intestinale d'atazanavir (ATV), un inhibiteur de la protéase du VIH-1. Le travail présenté dans le cadre de cette thèse avait pour objectifs : 1. de déterminer in vivo chez le rat l'effet d'un traitement par le SMX-TMP sur la pharmacocinétique de l'ATV et sur les modifications du microbiote intestinal. 2. d'analyser chez l'homme l'effet d'un traitement par le SMX-TMP sur les concentrations résiduelles d'ATV par l'étude rétrospective de données cliniques et pharmacologiques (Dat'AIDS) et de données internationales de pharmacovigilance de l'OMS (VigiBase). Chez le rat, le traitement par le SMX-TMP augmentait de façon importante les paramètres pharmacocinétiques d'ATV (AUC0-8h : 27201,6±4278,8 vs 2308,7±505,5 ng.mL-1.h, p=0,001) et diminuait significativement les Enterobacteriaceae (3,9±0,2 log10 vs 7,6±0,2 log10 copies ARNr 16S, p<0.01) au niveau du microbiote caecal. Les autres groupes bactériens ainsi que les bactéries totales n'étaient pas modifiés. Parallèlement, une augmentation significative du temps de transit intestinal total était observée. Chez l'homme, aucune différence significative concernant le seuil de toxicité des concentrations résiduelles d'ATV chez les patients traités par le SMX-TMP par rapport au groupe contrôle, odds ratio (OR) ajusté=1,4 (IC95% : 0,5-4,4) n'était observée. Concernant les données de pharmacovigilance, la proportion des patients traités par le SMX-TMP et l'ATV ayant présenté une hyperbilirubinémie, témoin d'une élévation des concentrations résiduelles d'ATV, n'était pas significativement différente de celle des patients traités par l'ATV seul, OR ajusté=0,9 (IC95% : 0,6-1,2). En conclusion, les résultats ex vivo observés chez le rat ne sont pas confortés par les résultats in vivo observés chez l'animal entier. L'augmentation des paramètres pharmacocinétiques d'ATV pourrait être la conséquence de l'allongement du temps de transit qui serait dû à une diminution de la synthèse de la sérotonine, consécutive à la modification du microbiote intestinal comme décrit par certains auteurs. Cette augmentation des paramètres pharmacocinétiques n'est pas observée chez l'homme. Cette apparente absence d'effet conforte la stratégie actuelle d'utilisation du SMX-TMP dans la prévention des infections opportunistes chez les patients infectés par le VIH et traités par l'ATV

Role of Cotrimoxazole in the pharmacological variability of Atazanavir and changes in gut microbiota

Le cotrimoxazole, sulfaméthoxazole-triméthoprime (SMX-TMP), est un antibiotique utilisé chez les patients infectés par le VIH en prophylaxie pour prévenir la survenue des infections opportunistes. Nous avons précédemment montré par une méthode ex-vivo utilisant les chambres d'Ussing que chez le rat, un traitement par le SMX-TMP entraînait au niveau du côlon une diminution de l'absorption intestinale d'atazanavir (ATV), un inhibiteur de la protéase du VIH-1. Le travail présenté dans le cadre de cette thèse avait pour objectifs : 1. de déterminer in vivo chez le rat l'effet d'un traitement par le SMX-TMP sur la pharmacocinétique de l'ATV et sur les modifications du microbiote intestinal. 2. d'analyser chez l'homme l'effet d'un traitement par le SMX-TMP sur les concentrations résiduelles d'ATV par l'étude rétrospective de données cliniques et pharmacologiques (Dat'AIDS) et de données internationales de pharmacovigilance de l'OMS (VigiBase). Chez le rat, le traitement par le SMX-TMP augmentait de façon importante les paramètres pharmacocinétiques d'ATV (AUC0-8h : 27201,6±4278,8 vs 2308,7±505,5 ng.mL-1.h, p=0,001) et diminuait significativement les Enterobacteriaceae (3,9±0,2 log10 vs 7,6±0,2 log10 copies ARNr 16S, p<0.01) au niveau du microbiote caecal. Les autres groupes bactériens ainsi que les bactéries totales n'étaient pas modifiés. Parallèlement, une augmentation significative du temps de transit intestinal total était observée. Chez l'homme, aucune différence significative concernant le seuil de toxicité des concentrations résiduelles d'ATV chez les patients traités par le SMX-TMP par rapport au groupe contrôle, odds ratio (OR) ajusté=1,4 (IC95% : 0,5-4,4) n'était observée. Concernant les données de pharmacovigilance, la proportion des patients traités par le SMX-TMP et l'ATV ayant présenté une hyperbilirubinémie, témoin d'une élévation des concentrations résiduelles d'ATV, n'était pas significativement différente de celle des patients traités par l'ATV seul, OR ajusté=0,9 (IC95% : 0,6-1,2). En conclusion, les résultats ex vivo observés chez le rat ne sont pas confortés par les résultats in vivo observés chez l'animal entier. L'augmentation des paramètres pharmacocinétiques d'ATV pourrait être la conséquence de l'allongement du temps de transit qui serait dû à une diminution de la synthèse de la sérotonine, consécutive à la modification du microbiote intestinal comme décrit par certains auteurs. Cette augmentation des paramètres pharmacocinétiques n'est pas observée chez l'homme. Cette apparente absence d'effet conforte la stratégie actuelle d'utilisation du SMX-TMP dans la prévention des infections opportunistes chez les patients infectés par le VIH et traités par l'ATV.Cotrimoxazole, sulfamethoxazole-trimethoprim (SMX-TMP), is an antibiotic used in HIV-infected patients in prophylaxis for the prevention of opportunistic infections. We have previously shown with an ex-vivo method using Ussing chambers that in rats, treatment with SMX-TMP resulted in a decrease in colonic absorption of atazanavir (ATV), an inhibitor of protease of HIV-1. The work presented in this thesis aims to: 1. determine in rats the in vivo effect of SMX-TMP treatment on the pharmacokinetics of ATV and changes in the gut microbiota. 2. analyze in human the effect of SMX-TMP treatment on the ATV trough plasma concentrations using a retrospective study of clinical and pharmacological data (Dat'AIDS) and international pharmacovigilance data from WHO (VigiBase). In rats, treatment with SMX-TMP significantly increased the pharmacokinetic parameters of ATV (AUC0-8h: 27201.6±4278.8 vs 2308.7±505.5 ng.mL-1.h, p=0.001) and decreased Enterobacteriaceae (3.9±0.2 log10 vs 7.6±0.2 log10 16S rRNA copies, p <0.01) in the caecal microbiota. Other bacterial groups as well as total bacteria were not modified. At the same time, a significant increase in total intestinal transit time was observed. In human, there was no significant difference in the proportion of patients who achieved the threshold of toxicity of ATV trough plasma concentrations between treated with SMX-TMP compared to the control group, adjusted odds ratio (OR) = 1.4 (95% CI: 0. 5-4.4). Regarding the pharmacovigilance data, the proportion of patients treated concomitantly with SMX-TMP and ATV who had hyperbilirubinemia, which is indicative of a rise in the ATV trough plasma concentrations, was not significantly different from that of patients treated with ATV alone, adjusted OR = 0.9 (95% CI: 0.6-1.2). In conclusion, the ex vivo results observed in the rat are not supported by the observed in vivo results in the whole animal. The increase in the pharmacokinetic parameters of ATV could be the consequence of the lengthening of the gastrointestinal transit time which would be due to a decrease in serotonin synthesis, following the modification of the gut microbiota as described by some authors. This increase in pharmacokinetic parameters is not observed in human. This apparent lack of effect reinforces the current strategy for using SMX-TMP in the prevention of opportunistic infections in HIV-infected patients treated with ATV

Metronidazole or Cotrimoxazole therapy is associated with a decrease in intestinal bioavailability of common antiretroviral drugs.

Metronidazole (MTZ) and Cotrimoxazole (CTX) are used in HIV/AIDS patients eligible for antiretroviral treatment. The objective of this animal study was to determine whether pre-treatment with antibiotics affects the intestinal bioavailability of Atazanavir (ATV) and Ritonavir (RTV). After oral administration of 1 mg MTZ and CTX for 7 days, the rat colonic mucosa were analyzed for mucus thickness or placed in Ussing chambers to measure ATV and RTV net transepithelial fluxes (Jnet). 1. In control rats, the mucus thickness was 43.3±7.6 µm and 40.7±6.9 µm, in proximal and distal colon, respectively. In proximal colon, the thickness was 57.2±8.8 and 58.2±6.9 µm after MTZ and CTX, respectively whereas in distal colon, the thickness was 121.1±38.4 and 170.5±35.0 µm (P<0.05) respectively. 2. Transepithelial conductance was reduced after MTZ or CTX in the proximal and distal colon. 3. In control, net ATV secretion was observed both in proximal (-0.36±0.02 µg.hr(-1) cm(-2)) and distal colon (-0.30±0.08 µg.hr(-1) cm(-2)). After MTZ and CTX, it was increased in the proximal colon by two 2 fold and 4 fold, respectively and in the distal colon by 3 fold and 5 fold, respectively. 4. In control, there was no net active RTV transport either in proximal (+0.01±0.01 µg.hr(-1) cm(-2)) or distal colon (+0.04±0.01 µg.hr(-1) cm(-2)). After MTZ and CTX, secretion was increased 5 fold and 10 fold, respectively, in the proximal colon and two fold and 5 fold, respectively in the distal colon (p<0.001). In conclusion, after MTZ and CTX therapy, the mucus layer was enlarged, passive permeability was decreased and ATV and RTV were actively secreted by the colonic epithelium suggesting that, in rat, the intestinal bioavailability of ATV and RTV is impaired after antibiotic therapy

Higher Atazanavir Plasma Exposure in Rats is Associated with Gut Microbiota Changes Induced by Cotrimoxazole

International audienceBackground: Cotrimoxazole (TMP-SMX) is concomitantly used as a primary prophylaxis of opportunistic infections with antiretroviral agents, such as Atazanavir (ATV). Results from an ex vivo study showed changes in intestinal absorption of ATV when rats were pretreated with TMP-SMX. The objective of this in vivo study is to determine the effect of TMP-SMX on the pharmacokinetics of ATV in rats. We also studied changes in gut microbiota induced by TMP-SMX. Methods: We used the non-compartment analysis to compare the pharmacokinetics of ATV in a parallel group of rats treated with a low or therapeutic dose of TMP-SMX for nine days to untreated control rats. Gut microbiota was characterized using qPCR and High Throughput Sequencing of 16S rDNA. Results: Rats treated with TMP-SMX showed a much broader exposure to ATV compared to the control group (AUC0-8h (ng.mL-1.h), 25975.9±4048.7 versus 2587.6±546.9, p=0.001). The main observation regarding the gut microbiota was a lower proportion of enterobacteria related to the administration of TMP-SMX. Moreover, the Total Gastrointestinal Transit Time (TGTT) was longer in the TMP-SMX treated group. Conclusion: Concomitant administration of TMP-SMX and ATV significantly increased ATV exposure in rats. This increase could be the result of a prolonged TGTT leading to an increase in the intestinal residence time of ATV favoring its absorption. Gut microbiota changes induced by TMP-SMX could be at the origin of this prolonged TGTT. If demonstrated in humans, this potential interaction could be accompanied by an increase in the adverse effects of ATV

Giochi di altruismo. L'approccio evoluzionistico alla cooperazione umana

This is the introductory essay to the Italian translation of Matt Ridley's "The origins of virtue", surveying the game-theoretic and evolutionary approaches to the emergence and evolution of cooperation and altruism

Mucus thickness of colonic mucus (mean ± SE) after 1 week pre-treatment with 1 mg of Cotrimoxazole (CTX) or 1 mg of Metronidazole (MTZ), compared to control in proximal and distal colon.

<p>*P<0.05 and ***P<0.001, n = 24 tissues from 7 rats.</p

Thickness of the total mucus layer in colonic mucosa in proximal 2) and distal segments 3) of control a), Metronidazole b) and Cotrimoxazole-treated rats c), AB/PAS staining.

<p>1) Magnification x 100 and x 400. The total mucus thickness (<b>M</b>) was measured as a continuous layer between the luminal surface (<b>L</b>) and epithelium (<b>E</b>). Increased thickness of the mucus layer was observed in MTZ and CTX treated rats (<b>b</b>, <b>c</b>). Goblet cells are filled with mucus (blue arrows) either in the control or the MTZ and CTX treated group. Occasionally, a separation could be observed between the mucus layer and the epithelial surface, and may be due to the partial mucus shrinkage during the histological procedure <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089943#pone.0089943-Ota1" target="_blank">[37]</a>.</p

Relationship between Mucus thickness (in µm) and Transepithelial electrical Conductance G_t (in mS/cm²).

<p>The data were obtained from the means of at least n = 13 tissues from 7 rats. Closed black dots indicate proximal colon and closed red dots distal colon (A). The relationship between Gt and mucus thickness (ML) were analyzed by nonlinear regression (curve fit) using the power series equation Y = AX^b (B). r² was 0.94. With 95% confidence limit if of A of 168.6 to 374.6 and B of −0.73 to −0.55, with covariance Matrix A and B = −0.99. Below the threshold of 42 µm the conductance (an index of ionic permeability) remained constant 25 mS/cm². In contrast, the conductance decreased with mucus thickness down to a limit value of 10 mS/cm².</p

Transepithelial electrical conductance (G_t) (mean ± SE) after 1 week of pre-treatment with 1 mg of Cotrimoxazole (CTX) or 1 mg of Metronidazole (MTZ) compared to controls, in proximal (A) and distal (B) colon.

<p>*p<0.05, ***P<0.001, n = 24 tissues from 7 rats.</p