SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The management of acute diarrheal disease in children must consider potential etiologic agents and their common presentation. The workup and assessment should be tailored to the clinical condition of the patient and the most likely pathogen. Management must primarily focus on fluid therapy and dietary manipulation. Antibiotics have a very restricted role as do antidiarrheal agents.
Loperamide is an antidiarrheal peripheral opiate agonist, with rare neurological secondary effects. We report the case of a 26-month-old child who had impaired consciousness under treatment by loperamide, and was treated successfully with naloxone. Limitations of the use of loperamide in young children are underlined. Naloxone may be used in case of impaired consciousness, for a diagnostic as well as therapeutic purpose.
Chronic pouchitis can be observed in up to 30% of patients after proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC). It remains a poorly understood complication and often requires chronic antibiotic and antidiarrheal treatment. We hypothesized that its occurrence can be predicted by distinct clinical parameters and that it adversely affects quality of life. Sixty-eight of 129 consecutive UC patients who underwent IPAA over a 10-year period were evaluated by Cleveland Clinic Global Quality of Life questionnaires, telephone interviews, and by chart review. Using bivariate comparison, clinical predictors for the occurrence of chronic pouchitis were sought, and postoperative data analyzed with regard to functional results and quality of life. Nineteen of 68 patients (28%) experienced chronic pouchitis, but its occurrence could not be predicted by any variable assessed. Patients with chronic pouchitis complained of more frequent fecal incontinence (32% vs. 4% in controls; P < 0.01), of more frequent bowel movements (7.7/day vs. 6.2/day; P < 0.05), and experienced severe abdominal pain more often (P < 0.05). Overall quality of life and satisfaction with surgery, as well as subjective health and energy levels were lower in patients with chronic pouchitis (P < 0.01); however, greater than 80% of these patients would consider undergoing the same procedure again.
BACKGROUND & AIMS: Diarrhea is a major cause of illness and death in children and young animals. The aim of this study was to investigate the possible therapeutic effect of bromelain, a proteolytic extract obtained from pineapple stems on bacterial toxin and second-messenger agonist-induced intestinal secretion. METHODS: The effect of bromelain pretreatment on short-circuit responses to Escherichia coli heat-labile enterotoxin, heat-stable enterotoxin, and Vibrio cholerae cholera toxin was evaluated in rabbit ileum mounted in Ussing chambers. RESULTS: Bromelain was 62% effective in preventing heat-labile enterotoxin-induced secretion, 51% effective against cholera toxin, and 35% effective against heat-stable enterotoxin [corrected]. Bromelain also prevented secretory changes caused by prostaglandin E2, theophylline, calcium-ionophore A23187, 8-bromoadenosine 3':5'-cyclic monophosphate, and 8-bromoguanosine 3':5'-cyclic monophosphate, well-known intracellular mediators of ion secretion. The efficacy of bromelain was not caused by reduced tissue viability resulting from its proteolytic effects on enterocytes, indicated by experiments measuring uptakes of nutrients into intestinal cells and experiments measuring short-circuit responses to glucose. CONCLUSIONS: Bromelain prevents intestinal fluid secretion mediated by secretagogues that act via adenosine 3':5'-cyclic monophosphate, guanosine 3':5'-cyclic monophosphate, and calcium-dependent signaling cascades. It may be clinically useful as an antidiarrheal drug.
PURPOSE: Although the somatostatin analog octreotide is currently used in the treatment of chemotherapy-induced diarrhea and secretory diarrhea associated with various disorders, its role in the management of radiation enteritis is not well defined. We performed a randomized study that compared octreotide acetate with diphenoxylate hydrochloride plus atropine sulfate, the drug commonly used as therapy for acute radiation-induced diarrhea (ARID). METHODS AND MATERIALS: Sixty-one patients with Grade 2 (four to six stools per day) or Grade 3 (> or = seven stools per day, National Cancer Institute Common Toxicity Criteria) diarrhea associated with pelvic radiotherapy were assigned randomly to receive octreotide s.c., 100 microg three times daily (n = 33) or diphenoxylate and atropine orally, 2.5 mg four times daily (n = 28). Radiotherapy was delivered to all patients in a conventional manner, with high-energy photons in a total dose > or =45 Gy, which exceeds the tolerance of intestine. Overall, there was no significant difference in patient characteristics or radiotherapy applied between the two arms. Patients were evaluated daily for the primary study end point, resolution of diarrhea, as well as for interruption of pelvic radiotherapy. RESULTS: Within 3 days, ARID completely resolved in 20 patients in the octreotide arm (2 within the first day, 11 within the second day, and 7 within the third day) vs. only 4 (all within the second day of therapy) in the diphenoxylate arm (p = 0.002). On the diphenoxylate arm, 15/28 patients were required to discontinue pelvic radiotherapy; on the octreotide arm, 6/33 patients were required to discontinue pelvic radiotherapy for an average of 1.89 +/- 0.5 and 0.45 +/- 0.2 days, respectively (p = 0.003). No side effects were observed in either arm. Three patients on the diphenoxylate arm and only 1 on the octreotide arm required further treatment for parenteral replenishment of fluids and electrolytes or other antidiarrheal treatments. CONCLUSION: Octreotide seems to be more effective than conventional therapy with diphenoxylate and atropine in controlling ARID and eliminating the need for radiotherapy interruptions.
Ten new delta6a,10a-THC analogs with arylalkyl side chains, one with a dimethylaminoalkyl side chain, and six heterocyclic delta6a,10a-THC analogs [8-substituted 5,5-dimethyl-10-hydroxy-2-(2-propynyl)-1,2,3,4-tetrahydro-5H-[1]benzo-pyrano[4,3-c]pyridines] were prepared. They showed pharmacological activity as analgesics, tranquilizers, antihypertensives, and hypnotics and as antisecretory, antiulcer, and antidiarrheal agents. The most potent compounds had either a 1-methyl-4-(4-fluorophenyl)butyl or a 1,2-dimethyl-4-(4-fluorophenyl)butyl side chain.
For a long time therapeutic agents that interact with opioid receptors have been used in antidiarrheal therapy. The action of the opioid active substances on motility and transit have already been characterized; however, their effects on myenteric reflexes and their possible luminal action have not yet been investigated. Loperamide, fedotozine and beta-casomorphin-4, as well as the casomorphin-analogue beta-CM-4027, are, or have been, suggested as therapeutic agents and were studied in the isolated rat ileum for their effect on the ascending reflex pathway. beta-CM-4027 > fedotozine > loperamide > beta-casomorphin-4 caused a concentration-dependent inhibition of the ascending contractile reflex response with an IC(50)of 1.4x10(-7)M, 1.5x10(-6)M, 4.1x10(-6)M and 4.5x10(-6)M respectively. At the same time as the oral contractile reflex response was inhibited, all four opioid agonists (CM-4027 > beta-casomorphin-4 > fedotozine > loperamide) increased the latency of the reflex response. Both effects were blocked by naloxone, indicating the involvement of opioid receptors. These results demonstrate that opioid-active drugs and substances modify the peristaltic reflex by reducing the efficacy of the reflex response and modulating the timing of the reflex pathway. In a second series of experiments, luminal application of opioid-active drugs was compared with serosal application. beta-casomorphine-4 caused a concentration-dependent inhibition of the oral reflex response with an IC(50)of 3x10(-3)M which was 750 times higher than after serosal application. In contrast, a stable and highly selective kappa opioid agonist (U-50,488), which caused potent inhibition upon serosal application (IC(50): 2.3x10(-7)M), showed no inhibitory effect after luminal application up to a concentration of 10(-2)M. Thus casomorphins could have a local effect on the gut wall with no need for systemic absorption. This might be used for a possible therapeutic application.
BACKGROUND: Racecadotril (acetorphan), an enkephalinase inhibitor with antisecretory and antidiarrheal actions, is an effective and safe treatment for acute diarrhea in adults and children. Whether treatment with racecadotril and oral rehydration therapy is more effective than treatment with oral rehydration alone in hospitalized children with acute watery diarrhea is not known. METHODS: We treated 135 boys 3 to 35 months of age who had watery diarrhea of five days' duration or less with racecadotril (1.5 mg per kilogram of body weight orally every eight hours) or placebo, in addition to oral rehydration solution. The primary end point was the 48-hour stool output (measured in grams); the total stool output, duration of diarrhea, and total intake of oral rehydration solution were also measured. RESULTS: The mean (+/-SE) 48-hour stool output was 92+/-12 g per kilogram in the racecadotril group and 170+/-15 g per kilogram in the placebo group (P<0.001), a 46 percent reduction with racecadotril. The results were similar among the 73 boys with rotavirus infections. The total stool output was 157+/-27 g per kilogram in the racecadotril group and 331+/-39 g per kilogram in the placebo group (P<0.001). The median duration of diarrhea was significantly less (P<0.001) in the racecadotril group (28 hours regardless of rotavirus status) than in the placebo group (72 and 52 hours, respectively, for rotavirus-positive and rotavirus-negative patients). The intake of oral rehydration solution was significantly lower in the racecadotril group than in the placebo group (P<0.001). Racecadotril was well tolerated; only seven patients taking racecadotril had adverse effects, which were all mild and transient. CONCLUSIONS: In young boys with acute watery diarrhea, racecadotril is an effective and safe treatment.
BACKGROUND: Although the antidiarrheal loperamide is a potent opiate, it does not produce opioid central nervous system effects at usual doses in patients. On the basis of in vitro studies demonstrating that loperamide is a substrate for the adenosine triphosphate-dependent efflux membrane transporter P-glycoprotein, we postulated that inhibition of P-glycoprotein with quinidine would increase entry of loperamide into the central nervous system with resultant respiratory depression. METHODS: To test this hypothesis, a 16-mg dose of loperamide was administered to eight healthy male volunteers in the presence of either 600 mg quinidine, a known inhibitor of P-glycoprotein, or placebo. Central nervous system effects were measured by evaluation of the respiratory response to carbon dioxide rebreathing as a measure of opiate-induced respiratory depression. RESULTS: Loperamide produced no respiratory depression when administered alone, but respiratory depression occurred when loperamide (16 mg) was given with quinidine at a dose of 600 mg (P < .001). These changes were not explained by increased plasma loperamide concentrations. CONCLUSION: This study therefore demonstrates first the potential for important drug interactions to occur by a new mechanism, namely, inhibition of P-glycoprotein, and second that the lack of respiratory depression produced by loperamide, which allows it to be safely used therapeutically, can be reversed by a drug causing P-glycoprotein inhibition, resulting in serious toxic and abuse potential.
BACKGROUND: The antidiarrheal drug loperamide is frequently used to treat ritonavir-associated diarrhea in patients with human immunodeficiency virus. The absence of marked central opioid effects has been attributed to its low bioavailability and its poor penetration of the blood-brain barrier, both of which might be altered by ritonavir, a potent P-glycoprotein and cytochrome P4503A inhibitor. METHODS: A 16-mg dose of loperamide was administered to 12 healthy male and female volunteers together with either 600 mg of ritonavir or placebo. Detailed pharmacokinetics of loperamide and its metabolites were determined over 72 hours. Central opioid effects were measured by evaluation of pupil diameter, cold pressor test, and transcutaneous PCO2 and PO2. RESULTS: Ritonavir caused a major pharmacokinetic interaction, increasing the area under the concentration-time curve of loperamide from 104 +/- 60 h x pmol/ml after placebo to 276 +/- 68 h. pmol/ml and delayed formation of the major metabolite desmethylloperamide (time to reach maximum concentration after drug administration [t(max)], 7.1 +/- 2.6 hours versus 19.6 +/- 9.1 hours). The urinary metabolic ratio of loperamide increased 3 times whereas the total molar amount of loperamide and metabolites excreted in urine remained unchanged. No central pharmacodynamic effects were observed after coadministration of loperamide with either ritonavir or placebo. CONCLUSION: This study demonstrates a major metabolic interaction probably by cytochrome P4503A4 with no evidence of P-glycoprotein involvement. This might explain the lack of central effects after ritonavir.
Diarrhea is a common gastrointestinal problem in diabetes, and its prevalence has been underestimated. The cause of diabetic diarrhea is unknown, but it is probably related to gastrointestinal motility disturbances secondary to diabetic autonomic neuropathy. Other causes (especially primary malabsorption syndromes and islet cell tumors) must be excluded. Treatment of diabetic diarrhea is largely symptomatic and only moderately effective. Antidiarrheal agents may ameliorate acute episodes. Broad-spectrum antibiotics and clonidine hydrochloride (Catapres) have had some success in long-term control. Most recently, subcutaneous administration of somatostatin analogues has been shown to be helpful, the main side effects being drowsiness and vomiting.
UNLABELLED: Loperamide is a peripherally acting antidiarrheal opioid with some affinity for P-glycoprotein (P-gp). One of the main reasons for its lack of central nervous system (CNS) activity is a combination first-pass metabolism and P-gp-mediated efflux preventing brain penetration. It was assumed that P-gp would also have a similar effect at the intestinal tract, limiting loperamide systemic absorption. However, previous in vitro studies had not determined loperamide flux using pH gradients present in the intestinal tract. Hence, our aim was to determine the influence of pH gradient conditions on the gastrointestinal uptake of loperamide, including any changes to its P-gp-mediated efflux. METHODS: Cellular uptake and transcellular transport were determined after exposure to various concentrations of loperamide (2-50 microM) with and without the presence of active efflux protein inhibitors. Loperamide was detected at 214 nm using high-performance liquid chromatography (HPLC) protocols. RESULTS: Bidirectional transport studies of 10 microM loperamide with a pH 6.0/7.4 apical (Ap)-to-basolateral (Bas) gradient showed efflux to be 17-fold higher than influx (10 ng/cm2/min Bas-->Ap compared to 0.6 for Ap-->Bas). This differential was much greater than when examined at pH 7.4/7.4 (only two-fold higher). The potent P-gp inhibitor, PSC-833, had only a moderate effect at blocking loperamide efflux under pH gradient conditions, yet could equilibrate bidirectional transport at pH 7.4. This suggested the presence of significant P-gp independent mechanisms, preventing loperamide access to the basolateral chamber. Amiloride and 5-(N-ethyl-N-isopropyl) amiloride had some effect on reducing efflux, hence the Na(+)--H(+) antiporter may have some involvement. Accumulation of loperamide into Caco-2 cells reduced almost 70% at pH 6.0 compared to pH 7.4, yet P-gp was always able to approximately double the equilibrium concentration in the cells within a defined pH study. This showed that P-gp was not affected by pH conditions. CONCLUSIONS: P-gp-mediated efflux of loperamide is supplemented under pH gradient conditions. Hence, drugs used to decrease acid secretion in the stomach could result in higher plasma loperamide levels based on our in vitro system reflecting the in vivo environment. The addition of a P-gp inhibitor could potentially further increase the gastrointestinal absorption of loperamide.
The present study was undertaken to compare the efficacy of a new calmodulin antagonist, zaldaride maleate, with that of placebo or loperamide in persons with traveler's diarrhea. One hundred seventy-nine patients were randomized to receive loperamide (4 mg followed by 2 mg after each unformed stool), zaldaride maleate (20 mg four times per day), or placebo. During the initial 48 hours of therapy, zaldaride maleate decreased the number of unformed stools by 30% and the duration of illness by 23% when compared with placebo. Loperamide was superior to both zaldaride maleate and placebo during the initial hours of treatment. However, after 48 hours of treatment, loperamide and zaldaride maleate were equally efficacious, decreasing by > 50% the number of unformed stools passed in a 24-hour interval (P, not significant), and were both superior when compared with placebo (P < .0001 and P = .0048, respectively). The apparent superiority of loperamide early in the course of therapy appeared to be related to a loading-dose effect and not to any differences in antidiarrheal properties.
The gastrointestinal tract is involved in both absorption and secretion of electrolytes and water, with absorption as the predominant process. In diarrheal diseases this balance is disturbed, and the result is net secretion. Most of the drugs used for the treatment of diarrhea at least partially act by stimulating absorption only, both stimulating absorption and inhibiting secretion, or inhibiting secretion only. The therapeutic usefulness of an antidiarrheal agent depends on how efficiently it alters secretion and/or absorption and on how few systemic adverse reactions it causes. When more information on the regulation of absorption and secretion has been accumulated, it may be possible to develop new drugs that can be aimed directly at these processes.
We report a case involving a fatal intoxication with loperamide (Imodium). Loperamide is a synthetic opioid of the phenyl piperidine class used as an over-the-counter antidiarrheal. It exerts its effects through interaction with micro-opiate receptors in the intestine to reduce peristalsis. Loperamide lacks the typical euphoric opiate effects when administered at recommended doses. Both loperamide and its major metabolite, N-desmethylloperamide, were isolated by liquid-liquid extraction into n-butyl chloride from alkalinized samples. Extracts were analyzed by liquid chromatography-electrospray-mass spectrometry in selected-ion-monitoring mode. Rapid separation of the drug, metabolite, and internal standard (diphenoxylate) was achieved using a high-resolution C18 column with 1.8-microm particle diameter. The mobile phase consisted of 0.1% formic acid in deionized water (60%) and acetonitrile (40%) at a flow rate of 0.5 mL/min. Heart blood concentrations for loperamide and its metabolite were 1.2 mg/L and 3.3 mg/L, respectively. In contrast, reported peak plasma concentrations of loperamide after administration of recommended daily doses of 16 mg did not exceed 0.012 mg/L in controlled trials. Because the heart blood ethanol concentration was 0.08 g/dL, the medical examiner ruled that the cause of death was loperamide and ethanol intoxication, and the manner of death as undetermined.
BACKGROUND: The efflux transporter P-glycoprotein, a member of the adenosine triphosphate-binding cassette superfamily, is a major determinant of the pharmacokinetics and pharmacodynamics of the opioid loperamide, a well-recognized antidiarrheal agent. Animal studies indicate that P-glycoprotein limits morphine entry into the brain. In this study, the authors examined whether other opioids of importance to anesthesiologists such as fentanyl, sufentanil, and alfentanil, and also morphine-6-glucuronide and morphine-3-glucuronide, are P-glycoprotein substrates and whether, in turn, these opioids act also as P-glycoprotein inhibitors. METHODS: The transcellular movement of the various opioids, including loperamide and morphine, was assessed in L-MDR1 (expressing P-glycoprotein) and LLC-PK1 cell monolayers (P-glycoprotein expression absent). A preferential basal-to-apical versus apical-to-basal transport in the L-MDR cells but not the LLC-PK1 cells is seen for P-glycoprotein substrates. In addition, the effect of the various opioids on the transcellular movement of the prototypical P-glycoprotein substrate digoxin was examined in Caco-2 cell monolayers. IC50 values were calculated according to the Hill equation. RESULTS: Loperamide was a substrate showing high dependence on P-glycoprotein in that basal-apical transport was nearly 10-fold greater than in the apical-basal direction in L-MDRI cells. Morphine also showed a basal-to-apical gradient in the L-MDR1 cell monolayer, indicating that it too is a P-glycoprotein substrate, but with less dependence than loperamide in that only 1.5-fold greater basal-apical directional transport was observed. Fentanyl, sufentanil, and alfentanil did not behave as P-glycoprotein substrates, whereas the morphine glucuronides did not cross the cell monolayers at all, whether P-glycoprotein was present or not. Loperamide, sufentanil, fentanyl, and alfentanil inhibited P-glycoprotein-mediated digoxin transport in Caco-2 cells with IC50 values of 2.5, 4.5, 6.5, and 112 microm, respectively. Morphine and its glucuronides (20 microm) did not inhibit digoxin (5 microm) transport in Caco-2 cells, and therefore IC50 values were not determined. CONCLUSIONS: Opioids have a wide spectrum of P-glycoprotein activity, acting as both substrates and inhibitors, which might contribute to their varying central nervous system-related effects.
Acute diarrhea in adults is usually caused by bacterial infection, parasitic infestation, food poisoning, or drugs. In this review, we summarize the pros and cons of medical therapies, point out certain areas of controversy, and propose a rationale for early intervention. Discussion is limited to the use of antidiarrheal agents and antibiotics in acute infectious diarrhea.
At our institution, proctocolectomy with rectal mucosectomy and ileoanal anastomosis with endorectal pull-through is now the procedure of choice for young patients with chronic ulcerative colitis and familial polyposis. We have followed up 66 patients (37 male and 29 female, with a median age of 16 years) for at least 6 months after closure of the temporary ileostomy. The patients were seen regularly in follow-up or were sent a comprehensive questionnaire to assess their condition. Twenty-two patients had the construction of a J-pouch, and 44 had a straight ileo-anal pull-through. Stool frequency, day (median 4 to 7 stools) and night (median 1 to 3 stools), was similar in the two groups. Voluntary continence was excellent in both groups during waking hours. Occasional night-time incontinence in small volumes, mild perianal itching, and minimal bleeding from irritation were similar in both groups. Most of the patients could distinguish gas from stool. When medication was used, bulk agents were usually chosen, with a nonspecific antidiarrheal agent taken occasionally. A few patients with the straight ileo-anal pull-through expressed some dissatisfaction early during the follow-up period; however, all but two patients expressed satisfaction later. Of the 66 patients, 41 had at least one complication during the postoperative period; however, in 26 the complications were minor. The more severe complications included small bowel obstruction (11 patients requiring surgical decompression), infection (one patient requiring surgery), and transient neuropathy (three patients).