The effect of drugs on bile flow and composition. An overview

Structure dependence and species sensitivity of in vivo hepatobiliary toxicity with lysophosphatidic acid receptor 1 (LPA1) antagonists

BMS-986020, BMS-986234 and BMS-986278, are three lysophosphatidic acid receptor 1 (LPA₁) antagonists that were or are being investigated for treatment of idiopathic pulmonary fibrosis (IPF). Hepatobiliary toxicity (elevated serum AST, ALT, and ALP, plasma bile acids [BAs], and cholecystitis) was observed in a Phase 2 clinical trial with BMS-986020, and development was discontinued. In dogs and rats, the species used for the pivotal toxicology studies, there was no evidence of hepatobiliary toxicity in the dog while findings in the rat were limited to increased plasma BAs levels (6.1× control), ALT (2.9×) and bilirubin (3.4×) with no histopathologic correlates. Since neither rats nor dogs predicted clinical toxicity, follow-up studies in cynomolgus monkeys revealed hepatobiliary toxicity that included increased ALT (2.0× control) and GLDH (4.9×), bile duct hyperplasia, cholangitis, cholestasis, and cholecystitis at clinically relevant BMS-986020 exposures with no changes in plasma or liver BAs. This confirmed monkey as a relevant species for identifying hepatobiliary toxicity with BMS-986020. In order to assess whether the toxicity was compound-specific or related to LPA₁ antagonism, two structurally distinct LPA₁ antagonists (BMS-986234 and BMS-986278), were evaluated in rat and monkey. There were no clinical or anatomic pathology changes indicative of hepatobiliary toxicity. Mixed effects on plasma bile acids in both rat and monkey has made this biomarker not a useful predictor of the hepatobiliary toxicity. In conclusion, the nonclinical data indicate the hepatobiliary toxicity observed clinically and in monkeys administered BMS-986020 is compound specific and not mediated via antagonism of LPA₁.

Low phospholipid-associated cholelithiasis syndrome: A rare cause of acute pancreatitis that should not be neglected

BACKGROUND

Low phospholipid-associated cholelithiasis (LPAC) syndrome is a very particular form of biliary lithiasis with no excess of cholesterol secretion into bile, but a decrease in phosphatidylcholine secretion, which is responsible for stones forming not only in the gallbladder, but also in the liver. LPAC syndrome may be underreported due to a lack of testing resulting from insufficient awareness among clinicians.

AIM

To describe the clinical and radiological characteristics of patients with LPAC syndrome to better identify and diagnose the disease.

METHODS

We prospectively evaluated all patients aged over 18 years old who were consulted or hospitalized in two hospitals in Paris, France (Bichat University Hospital and Croix-Saint-Simon Hospital) between January 1, 2017 and August 31, 2018. All patients whose profiles led to a clinical suspicion of LPAC syndrome underwent a liver ultrasound examination performed by an experienced radiologist to confirm the diagnosis of LPAC syndrome. Twenty-four patients were selected. Data about the patients’ general characteristics, their medical history, their symptoms, and their blood tests results were collected during both their initial hospitalization and follow-up. Cytolysis and cholestasis were expressed compared to the normal values (N) of serum aspartate and alanine transaminase activities, and to the normal value of alkaline phosphatase level, respectively. The subjects were systematically reevaluated and asked about their symptoms 6 mo after inclusion in the study through an in-person medical appointment or phone call. Genetic testing was not performed systematically, but according to the decision of each physician.

RESULTS

Most patients were young (median age of 37 years), male (58%), and not overweight (median body mass index was 24). Many had a personal history of acute pancreatitis (54%) or cholecystectomy (42%), and a family history of gallstones in first-degree relatives (30%). LPAC syndrome was identified primarily in patients with recurring biliary pain (88%) or after a new episode of acute pancreatitis (38%). When present, cytolysis and cholestasis were not severe (2.8N and 1.7N, respectively) and disappeared quickly. Interestingly, four patients from the same family were diagnosed with LPAC syndrome. At ultrasound examination, the most frequent findings in intrahepatic bile ducts were comet-tail artifacts (96%), microlithiasis (83%), and acoustic shadows (71%). Computed tomography scans and magnetic resonance imaging were performed on 15 and three patients, respectively, but microlithiasis was not detected. Complications of LPAC syndrome required hospitalizing 18 patients (75%) in a conventional care unit for a mean duration of 6.8 d. None of them died. Treatment with ursodeoxycholic acid (UDCA) was effective and well-tolerated in almost all patients (94%) with a rapid onset of action (3.4 wk). Twelve patients’ (67%) adherence to UDCA treatment was considered “good.” Five patients (36%) underwent cholecystectomy (three of them were treated both by UDCA and cholecystectomy). Despite UDCA efficacy, biliary pain recurred in five patients (28%), three of whom adhered well to treatment guidelines.

CONCLUSION

LPAC syndrome is easy to diagnose and treat; therefore, it should no longer be overlooked. To increase its detection rate, all patients who experience recurrent biliary symptoms following an episode of acute pancreatitis should undergo an ultrasound examination performed by a radiologist with knowledge of the disease.

Multiple intraintestinal signals coordinate the regulation of Vibrio cholerae virulence determinants

Vibrio cholerae is a Gram-negative motile bacterium capable of causing fatal pandemic disease in humans via oral ingestion of contaminated water or food. Within the human intestine, the motile vibrios must evade the innate host defense mechanisms, penetrate the mucus layer covering the small intestine, adhere to and multiply on the surface of the microvilli and cause disease via the action of cholera toxin. The explosive diarrhea associated with V. cholerae intestinal colonization leads to dissemination of the vibrios back into the environment to complete this phase of the life cycle. The host phase of the vibrio life cycle is made possible via the concerted action of a signaling cascade that controls the synthesis of V. cholerae colonization determinants. These virulence proteins are coordinately synthesized in response to specific host signals that are still largely undefined. A more complete understanding of the molecular events involved in the V. cholerae recognition of intraintestinal signals and the subsequent transcriptional response will provide important information regarding how pathogenic bacteria establish infection and provide novel methods for treating and/or preventing bacterial infections such as Asiatic cholera. This review will summarize what is currently known in regard to host intraintestinal signals that inform the complex ToxR regulatory cascade in order to coordinate in a spatial and temporal fashion virulence protein synthesis within the human small intestine.

The capacity and effectiveness of diosmectite and charcoal in trapping the compounds causing the most frequent intoxications in acute medicine: A comparative study

The aim of the study was to compare the adsorption ability of two adsorbent materials, namely diosmectite and activated charcoal towards selected model compounds that are most commonly involved in acute intoxication. Eleven model compounds were selected: acetylsalicylic acid, α-amanitin, amlodipine, digoxin, phenobarbital, ibuprofen, imipramine, carbamazepine, oxazepam, promethazine, and theophylline. Of the tested compounds, promethazine and imipramine were the most effectively adsorbed to diosmectite. Their adsorption to diosmectite (0.356±0.029mg promethazine/mg diosmectite and 0.354±0.019mg imipramine/mg diosmectite, respectively) was significantly higher than their adsorption to activated charcoal. The effect of temperature and pH on the adsorption efficiencies was also evaluated. In the case of experiments with mixture of both adsorbents, they mostly behaved in a solution independently or in a slightly antagonistic way. Using various methods such as N₂ adsorption and thermogravimetric analysis, the structure and texture of diosmectite and activated charcoal were attained.

Intestinal GPS: bile and bicarbonate control cyclic di-GMP to provide Vibrio cholerae spatial cues within the small intestine

The second messenger cyclic di-GMP (c-di-GMP) regulates numerous phenotypes in response to environmental stimuli to enable bacteria to transition between different lifestyles. Here we discuss our recent findings that the human pathogen Vibrio cholerae recognizes 2 host-specific signals, bile and bicarbonate, to regulate intracellular c-di-GMP. We have demonstrated that bile acids increase intracellular c-di-GMP to promote biofilm formation. We have also shown that this bile-mediated increase of intracellular c-di-GMP is negated by bicarbonate, and that this interaction is dependent on pH, suggesting that V. cholerae uses these 2 environmental cues to sense and adapt to its relative location in the small intestine. Increased intracellular c-di-GMP by bile is attributed to increased c-di-GMP synthesis by 3 diguanylate cyclases (DGCs) and decreased expression of one phosphodiesterase (PDE) in the presence of bile. The molecular mechanisms by which bile controls the activity of the 3 DGCs and the regulators of bile-mediated transcriptional repression of the PDE are not yet known. Moreover, the impact of varying concentrations of bile and bicarbonate at different locations within the small intestine and the response of V. cholerae to these cues remains unclear. The native microbiome and pharmaceuticals, such as omeprazole, can impact bile and pH within the small intestine, suggesting these are potential unappreciated factors that may alter V. cholerae pathogenesis.

Bile salts and their importance for drug absorption

Bile salts are present in the intestines of humans as well as the animals used during the development of pharmaceutical products. This review provides a short introduction into the physical chemical properties of bile salts, a description of the bile concentration and composition of bile in different animal species and an overview of the literature investigating the influence of bile salts on the in vivo performance of different compounds and drug formulations. Generally, there is a positive effect on bioavailability when bile is present in the gastro-intestinal tract, independent of the formulation systems, e.g. suspensions, solutions, cyclodextrin complexes or lipid based formulations, but a few exceptions have also been reported.

Dietary roles of non-starch polysaccharides in human nutrition: a review

Nonstarch polysaccharides (NSPs) occur naturally in many foods. The physiochemical and biological properties of these compounds correspond to dietary fiber. Nonstarch polysaccharides show various physiological effects in the small and large intestine and therefore have important health implications for humans. The remarkable properties of dietary NSPs are water dispersibility, viscosity effect, bulk, and fermentibility into short chain fatty acids (SCFAs). These features may lead to diminished risk of serious diet related diseases which are major problems in Western countries and are emerging in developing countries with greater affluence. These conditions include coronary heart disease, colo-rectal cancer, inflammatory bowel disease, breast cancer, tumor formation, mineral related abnormalities, and disordered laxation. Insoluble NSPs (cellulose and hemicellulose) are effective laxatives whereas soluble NSPs (especially mixed-link β-glucans) lower plasma cholesterol levels and help to normalize blood glucose and insulin levels, making these kinds of polysaccharides a part of dietary plans to treat cardiovascular diseases and Type 2 diabetes. Moreover, a major proportion of dietary NSPs escapes the small intestine nearly intact, and is fermented into SCFAs by commensal microflora present in the colon and cecum and promotes normal laxation. Short chain fatty acids have a number of health promoting effects and are particularly effective in promoting large bowel function. Certain NSPs through their fermented products may promote the growth of specific beneficial colonic bacteria which offer a prebiotic effect. Various modes of action of NSPs as therapeutic agent have been proposed in the present review. In addition, NSPs based films and coatings for packaging and wrapping are of commercial interest because they are compatible with several types of food products. However, much of the physiological and nutritional impact of NSPs and the mechanism involved is not fully understood and even the recommendation on the dose of different dietary NSPs intake among different age groups needs to be studied.

Ursodeoxycholic acid promotes intestinal adaptation in a cat model of short bowel syndrome

The aim of this study was to assess the effect of ursodeoxycholic acid (UDCA) on the morphological and functional adaptive response of the jejunal remnant after massive intestinal resection in a cat model of short bowel syndrome (SBS). UDCA was administered to animals at a daily oral dose of 15 mg/kg for 6 weeks following a 85% jejunoileal resection. Resection alone caused extensive hyperplasia of jejunal mucosa, as evidenced by a significant increase in the weight of jejunal mucosa per unit length as well as by significant increases in DNA and protein concentration but no change in the protein/DNA ratio. Morphometric analysis using microscopy revealed no changes in jejunal mucosa thickness, jejunal crypt depth, villus height and villus surface area, although villus thickness was increased. The specific activities of jejunal sucrase and alkaline phosphatase were unaffected. UDCA treatment of resected animals, using doses that caused no toxicity, as evidenced by the absence of serum biochemistry abnormalities and histopathology, did not induce, compared to resection alone, any changes in mucosal cellularity and did not affect villus morphometry. On the other hand, UDCA administration increased crypt depth and, also, induced a profound increase in the specific activity of sucrase. UDCA improved diarrhoea, a core SBS symptom, reflected in a considerably reduced frequency of defaecation and improved form and texture of faeces. It is concluded that UDCA administration may enhance the natural adaptive response of the intestinal remnant following massive jejunoileal resection and may, thus, be beneficial in SBS treatment.

Bile acids for liver-transplanted patients

BACKGROUND

Liver transplantation has become a widely accepted form of treatment for numerous end-stage liver diseases. Bile acids may decrease allograft rejection after liver transplantation by changing the expression of major histocompatibility complex class molecules in bile duct epithelium and central vein endothelium.

OBJECTIVES

To assess the beneficial and harmful effects of bile acids for liver-transplanted patients.

SEARCH STRATEGY

We performed searches of The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Expanded to September, 2009.

SELECTION CRITERIA

Randomised clinical trials comparing any dose of bile acids or duration of treatment in liver-transplanted patients versus placebo, no intervention, or another intervention. We included randomised clinical trials irrespective of blinding, language, and publication status.

DATA COLLECTION AND ANALYSIS

Two review authors extracted and checked data independently. We evaluated the risk of bias of the trials from the method of allocation sequence generation, allocation concealment, blinding, outcome data analysis, outcome data reporting, and other potential sources of bias. We used the intention-to-treat principle to perform meta-analyses and presented the outcomes as relative risks (RR) or mean differences (MD), both with 95% confidence intervals (CI).

MAIN RESULTS

The updated search resulted in no new trials meeting the inclusion criteria of this review, thus leaving it to the seven already included randomised trials (six evaluating ursodeoxycholic acid versus placebo or no intervention, and one evaluating tauro-ursodeoxycholic acid versus no intervention) enrolling a total of 335 participants. The administration of bile acids began one day or more after liver transplantation. All patients received the standard triple-drug immunosuppressive regimen (steroids, azathioprine, and cyclosporine or tacrolimus) to suppress the allograft rejection response after liver transplantation. Bile acids compared with placebo or no intervention did not significantly change all-cause mortality (RR 0.85, 95% CI 0.53 to 1.36), mortality related to allograft rejection (RR 0.30, 95% CI 0.01 to 7.12), retransplantation (RR 0.76, 95% CI 0.20 to 2.86), acute cellular rejection, or number of patients with steroid-resistant rejection. Bile acids significantly reduced the number of patients who had chronic rejection in a fixed-effect model but not in a random-effects model meta-analysis. Bile acids were safe and well tolerated by liver-transplanted patients. However, this observation is based on data analysis from three trials with only 187 patients.

AUTHORS' CONCLUSIONS

We did not find evidence to support or refute bile acids for liver-transplanted patients. Further randomised trials are necessary before bile acids can be recommended to liver-transplanted patients.

Evaluation of a surgical procedure to measure drug biliary excretion of rats in regulatory safety studies

A surgical procedure was evaluated to allow bile collection from the freely moving male Sprague-Dawley rats for the assessment of drug biliary excretion during regulatory safety studies. A catheter was implanted into the bile duct to divert the bile flow via an exteriorized loop. Following recovery from the surgery and verification of normal hepatic function, the exteriorized catheter was sectioned to allow collection of the bile and replacement with a commercial bile salt solution. Approximately 80% of the catheterized animals (10 females and 10 males) had normal serum liver enzyme levels 2 days after surgery. Then, the effect of acute or repeated administrations of the immunosuppressant tacrolimus on the biliary excretion of 14C diazepam was studied to validate the technique. A first group of 12 rats received an intravenous injection of 10 mg/kg 14C-diazepam and the total and sequential amounts of diazepam excreted in the bile were measured over 72 h. Biliary excretion accounted for 80% of diazepam elimination. These rats were then given an oral administration of 3 mg/kg tacrolimus on days 7 and 8 followed by the same intravenous dose of 14C-diazepam. Another group of 10 catheterized rats was given 21 daily oral doses of 3 mg/kg tacrolimus followed by a single intravenous administration of 14C-diazepam. No significant changes in diazepam biliary excretion were observed following either acute or repeated administration of tacrolimus. This study demonstrates the feasibility of drug biliary excretion investigations under Good Laboratory Practices conditions as a complement to regulatory acute or repeated dose safety studies.

Bile acids for liver-transplanted patients

BACKGROUND

Liver transplantation has become a widely accepted form of treatment for numerous end-stage liver diseases. Bile acids may decrease the degree of allograft rejection after liver transplantation by changing the expression of major histocompatibility complex class molecules in bile duct epithelium and central vein endothelium.

OBJECTIVES

To assess the beneficial and harmful effects of bile acids for liver-transplanted patients.

SEARCH STRATEGY

We performed searches of the Cochrane Hepato-Biliary Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE to April 2003. We also searched The Chinese Biomedical Database to May 2002.

SELECTION CRITERIA

Randomised clinical trials comparing any dose of bile acids or duration of treatment in liver-transplanted patients versus placebo, no intervention, or another intervention. We included randomised clinical trials irrespective of blinding, language, and publication status.

DATA COLLECTION AND ANALYSIS

W Chen extracted the data and C Gluud validated them. We evaluated the methodological quality of the trials from the method for generation of the allocation sequence, allocation concealment, double blinding, and follow-up. We used the intention-to-treat principle to perform meta-analyses and presented the outcomes as relative risk (RR) or weighted mean difference (WMD), both with 95% confidence intervals (CI).

MAIN RESULTS

We identified seven randomised trials (six evaluating ursodeoxycholic acid versus placebo or no intervention and one evaluating tauro-ursodeoxycholic acid versus no intervention) with a total of 335 liver-transplanted patients. The administration of bile acids began one day or more after liver transplantation. All patients received the standard triple-drug immunosuppressive regimen (steroids, azathioprine, and cyclosporine or tacrolimus) to suppress the allograft rejection response after liver transplantation. Bile acids did not significantly reduce all-cause mortality, mortality related to allograft rejection, retransplantation, acute cellular rejection, or number of patients with steroid-resistant rejection. Bile acids significantly reduced the number of patients who had chronic rejection in a fixed-effect model but not in a random-effects model. Bile acids were safe and well tolerated by liver-transplanted patients.

AUTHORS' CONCLUSIONS

Bile acids do not seem to have significant beneficial effects in liver-transplanted patients.

Hepatic effects in beagle dogs administered atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, for 2 years

The chronic toxicity of atorvastatin (AT), an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, was evaluated in beagle dogs. Dogs were treated with 0, 10, 40, or 120 mg/kg of AT daily. Treatment lengths were 52 wk, 52 wk followed by 12 wk without drug, or 104 wk. Decreases in cholesterol levels were dose related and stable throughout the treatment period. Increases in alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase were transient and dose related in severity at > or = 40 mg/kg. Two dogs administered 120 mg/kg of AT daily were sacrificed moribund during the first 9 wk of treatment. Hepatic lesions were reversible with or without continued treatment and dose related in severity and distribution. Hepatic microgranulomas and hepatocellular degeneration were seen at the 120-mg/kg dose in dogs sacrificed before 53 wk. Before 53 wk, hepatocellular lipofuscin deposits were increased in dogs given > or = 40 mg/kg of AT daily but were similar to controls after 12 wk without drug and after 104 wk of continuous treatment. Bile stasis occurred in dogs given > or = 40 mg/kg of AT daily at all time points but was less severe after reversal and at week 104 compared with week 52.

Effect of sodium tauroursodeoxycholate (UR-906) on liver dysfunction in bile duct-ligated rats

We investigated the effect of sodium tauroursodeoxycholate (UR-906) on cholestasis in common bile duct-ligated rats in comparison with the effect of dehydrocholic acid. UR-906 (30-180 mumol/kg) and dehydrocholic acid (180 mumol/kg) were intravenously given once daily for consecutive 20 days in rats and the common bile duct was ligated for the last 10 days. On the next day after the last test drug administration, serum biochemical and plasma hemostatic variables were determined. UR-906 significantly ameliorated the elevation of serum cholesterol, phospholipid, bilirubin and bile acid concentrations in bile duct-ligated rats. UR-906 significantly suppressed the prolongation of plasma prothrombin time and activated partial thromboplastin time. Furthermore, UR-906 significantly suppressed the decreases in plasma coagulation factor II and X activities. However, dehydrocholic acid did not cause significant changes in any of the variables examined in this model. These results suggest that UR-906 has a beneficial effect against cholestasis induced by bile duct ligation in rats and that this drug may be useful in the treatment of clinical cholestatic disorders.

Subchronic toxicity of atorvastatin, a hydroxymethylglutaryl-coenzyme A reductase inhibitor, in beagle dogs

The toxicity of atorvastatin (AT), an inhibitor of hydroxymethylglutaryl-coenzyme A reductase (HMG), was evaluated in beagle dogs. In 4 studies [2-wk rising dose (daily increasing doses for 1 wk; maintenance for 1 wk), 12-wk rising dose (daily dosing with weekly increases in dose), 2-wk toxicity (daily dosing for 2 wk; 3 dose levels), 13-wk toxicity (daily dosing for 13 wk; 3 dose levels)], dogs received up to 400 mg/kg orally. Doses of 180 mg/kg induced moribundity, necessitating euthanasia. Weight losses up to 26% were seen at doses > or = 150 mg/kg. Decreases in cholesterol levels were dose-related. Alanine and/or aspartate aminotransferase were increased at doses > or = 80 mg/kg; alkaline phosphatase was increased at doses > or = 150 mg/kg. Histopathologic findings were seen at > or = 150 mg/kg and included hepatocellular eosinophilia related to increased smooth endoplasmic reticulum and cholangiohepatitis and cholecystitis at 150 mg/kg in the 2-wk toxicity study; hepatocellular degeneration, centrilobular bridging, cholecystitis, hemorrhage in gallbladder and brain, demyelination of optic nerve, and skeletal muscle necrosis at > or = 280 mg/kg in the 12-wk rising dose study; and erosion and hemorrhage in large intestine, hepatocellular degeneration and necrosis, and inflammation and necrosis of gallbladder epithelium at 320 mg/kg in the 2-wk rising dose study. Doses up to 80 mg/kg for 13 wk did not induce histopathologic lesions in examined organs. AT effectively lowered serum cholesterol in normal lipidemic dogs. Toxicity at AT in dogs was similar to that with other inhibitors of HMG except that lenticular changes were not seen, significant hepatic, testicular, or neurological toxicity was associated only with high doses at AT, and skeletal muscle changes similar to those described in rats and rabbits were identified.

Effect of withdrawal of pravastatin on biliary lipid composition in humans

Abrupt withdrawal of HMG-CoA reductase inhibitors is associated with increased excretion of cholesterol into bile, but this phenomenon has not been investigated in humans. In order to evaluate whether patients interrupting these hypolipidemic drugs are at increased risk of forming gallstones, pravastatin (40 mg twice a day) or placebo was randomly administered to 16 bile fistula patients for 5 days. Biliary lipid composition was determined in basal conditions and for 5 consecutive days after drug withdrawal. Both biliary cholesterol concentration and saturation increased significantly on the second day after pravastatin withdrawal, but tended to decrease thereafter. Biliary bile acids and phospholipids were not affected. This short-lasting effect on biliary cholesterol excretion was probably the result of a transient increase of hepatic cholesterol synthesis by the up-regulated HMG-CoA reductase in the absence of the inhibitory drug. These results are consistent with the hypothesis that, also in humans, biliary cholesterol excretion could be dependent on the hepatic free cholesterol pool.

A cholecystokinin receptor antagonist, loxiglumide, stimulates biliary secretion in conscious rats

The effects of the CCK receptor antagonists loxiglumide [D,L-4-(3,4-dichlorobenzoylamino)-5-(N-3-methoxy-propylpentylam ino)-5-oxo- pentanoic acid, CR 1505] and MK-329 [3S(-)-N-(2,3-dihydro-1-methyl-2-oxo-5-phenyl-1H-1,4-benzo-diazepine-3-y l)-1H - indole-2-carboxamide, L-364,718], on bile flow were investigated in conscious rats. The bile duct of male Wistar rats was cannulated to directly collect pure bile, and the second cannula was inserted into the duodenum for reinfusion of bile. On the 4th through 7th postoperative days loxiglumide (25, 50 or 100 mg/kg body weight), MK-329 (1 mg/kg body weight) or the respective solvent (saline and 80% dimethyl sulfoxide) was injected subcutaneously. Loxiglumide caused dose-dependent increases in bile flow and bile acid output with a slight non-dose-dependent increase in bilirubin output. The integrated increments of bile flow during a 3-h period after saline and 100 mg/kg body weight loxiglumide were -14 +/- 71 and 982 +/- 61 microliters/100 g body weight, respectively, and those of bile acids were 2.5 +/- 1.4 and 23.1 +/- 4.1 mumol/100 g body weight, respectively. In contrast, MK-329 markedly decreased the bile flow (-439 +/- 76 vs. control; -32.8 +/- 76 microliters/100 g body weight/3 h, P < 0.001) and bile acids output (-16.3 +/- 6.8 vs. control; 3.4 +/- 3.8 mumol/100 g body weight/3 h, P < 0.001), while it significantly increased bilirubin output (86.4 +/- 15.6 vs. 43.5 +/- 1.1 mg/100 g body weight/3 h, P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Biological rhythms in the absorption, distribution, metabolism and excretion of drugs

Studies carried out in the last 20 years indicated that biological rhythms can be detected in the pharmacokinetics of most classes of drugs. These time-dependent variations could be due to parallel changes in the physiological functions and variables involved in the absorption, distribution, metabolism and excretion of drugs. A review of the data available suggests that the peak and trough values of these functions and variables do not occur at the same hour of the day in every factor involved in drug disposition. This information could be used to predict the time-dependent changes in the pharmacokinetics. The presence of circadian variations in the kinetics of drugs raise the rather old question: "When to administer drug?"

Ultrasonography detected a higher incidence of gallstones in psychiatric inpatients

A total of 105 psychiatric inpatients (55 men, 50 women) were investigated for gallstones and associated factors by means of ultrasonography. Gallstones were detected in 27 (26%) of the 105 patients. The overall incidence tended to be higher in female patients than in males. The duration of mental illness and neuroleptic medication in patients with gallstones was significantly longer than in those without gallstones. A stepwise discriminant analysis revealed that the duration of neuroleptic medication was the most informative for discrimination between the 2 groups. These results, in combination with previous studies on the effects of neuroleptics on the bile and biliary system, suggests that neuroleptics may accelerate the formation of gallstones.