Interactions of indomethacin with lysosomes and proteins

The stabilizing action of indomethacin on lysosomes and protein in vivtro was studied. The magnitude of the stabilizing action on lysosomes was greater than that of aspirin or oxyphenbutazone, similar to that of phenylbutazone, but less than that of prednisolone. The stabilizing action of indomethacin on lysosomes possibly may contribute to its anti-inflammatory properties.     

Effect of indomethacin and sodium meclofenamate on the renal concentrating defect in experimental enterococcal pyelonephritis in rats

The present studies have confirmed a severe urinary concentrating defect early in the course of experimental enterococcal pyelonephritis. This defect in maximum concentrating ability was almost completely reversed immediately following indomethacin or sodium meclofenamate intravenously. This effect of indomethacin and sodium meclofenamate was transient and was not associated with a fall in numbers of enterococci per gram of kidney. Injection of indomethacin or sodium meclofenamate in noninfected rats had no effect on maximum renal concentrating ability. The potential mechanisms by which indomethacin and sodium meclofenamate, inhibitors of renal prostaglandin synthesis, could reverse a defect in maximum urinary concentration are discussed.     

A meta-analysis of the effects of nonsteroidal anti-inflammatory drugs on blood pressure

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) have well-known gastrointestinal and renal toxic reactions. Effects of NSAIDs on blood pressure are less appreciated. A meta-analysis was performed to determine the hypertensive effects of NSAIDs and rank them by magnitude of change in mean arterial pressure (MAP). METHODS: A literature search of published English-language studies of NSAIDs and their effects on blood pressure was done. Studies were included if they met the following criteria: (1) the studies were intervention studies; (2) NSAIDs at any dose or aspirin at doses of 1.5 g/d or greater were included; (3) documentation of blood pressure was provided; and (4) the studies were 24 hours in duration. Studies were excluded if 20% or more of their participants dropped out or if the dose of antihypertensive drugs was adjusted while the subjects were taking NSAIDs. The major outcome was change in MAP while patients were receiving NSAIDs. Each NSAID arm was extracted from its trial. Information on possible confounders, including subject age, trial quality, amount of dietary salt intake, and whether study subjects were hypertensive or normotensive, was recorded. We calculated the average change in MAP on each NSAID, adjusting for confounders. RESULTS: Fifty-four studies with 123 NSAID treatment arms met inclusion criteria. The mean age of subjects was 46 years. Of the 1324 participants, 1213 subjects (92%) were hypertensive. The effects of NSAIDs on blood pressure were found solely in hypertensive subjects. Among these, the increase in MAP after adjusting for amount of dietary salt intake was 3.59 mm Hg for indomethacin (57 treatment arms), 374 mm Hg for naproxen (four arms), and 0.49 mm Hg for piroxicam (four arms). The MAP decreased by 2.59 mm Hg for placebo (10 arms), 0.83 mm Hg for ibuprofen (six arms), 1.76 mm Hg for aspirin (four arms), and 0.16 mm Hg for sulindac (23 arms). The effects on MAP by using placebo, sulindac, and aspirin were statistically significantly different from indomethacin. CONCLUSIONS: In short-term use, NSAIDs vary considerably in their effect on blood pressure. Of the drugs studied, indomethacin and naproxen were associated with the largest increases in blood pressure. The average effects of piroxicam, aspirin, ibuprofen, and sulindac were negligible.     

The effect of indomethacin and other anti-inflammatory drugs on the renin-angiotensin system

The administration of two different doses of indomethacin, 9 and 18 mg/kg, to two different groups of rabbits was followed 6 h later by a significant decrease in plasma renin activity, and these levels were not increased by hemorrhage. The administration of 2 mg/kg of indomethacin did not alter the basal levels of plasma renin activity, but it was effective in diminishing the peripheral increase of renin produced by hemorrhage. Similar effects were obtained in other groups of rabbits treated with 9 mg/kg of meclofenamate or 18 mg or aspirin. The lowering effect of indomethacin on plasma renin activity is not specifically related to hemorrhage because it also prevented the increase in plasma renin activity elicited by 5 mg/kg of furosemide. Further studies showed that indomethacin did not exert any significant effect in vivo on the plasma level of renin substrate or on the generation of angiotensin from normal plasma by exogenous renin. And indomethacin did not interfere with the binding capacity of anti-angiotensin I for angiotensin I in the radioimmunoassay reaction or with the in vitro formation of angiotensin from hog renin-nephrectomized rabbit plasma reaction. The results thus indicate that the lowering effect of indomethacin on plasma renin activity is due to the interference with renal renin release. That this effect may be related to the blockade of prostaglandin synthesis is suggested by the similar effect exhibited by other blockers of prostaglandin synthesis.     

Urolithiasis related to laxative abuse

Urinary calcareous disease related to laxative abuse is rare. The gastrointestinal loss of fluid and electrolytes leads to chronic depletion of the urinary volume, relative supersaturation and many other pathophysiologic derangements. These calculi are generally radiolucent with uric acid and ammonium acid urate as major components. We report on a female patient with frequent, repetitive formation of urinary calculi and rapid double J stent encrustation, which were related to the chronic abuse of bisacodyl. Although these stones can be fragmented successfully by extracorporeal shockwave lithotripsy, it seems that the better treatment for this type of stone formation is to avoid the abuse of laxatives.     

Problem dieting behaviors among young adolescents

OBJECTIVE: To examine dieting, eating and exercise behaviors, use of diet pills, and vomiting or use of laxatives to lose weight among younger adolescents. DESIGN: Analysis of data from a modified version of the Youth Risk Behavior Survey administered to middle school students in North Carolina in 1995. SETTING: Fifty-three randomly selected middle schools in North Carolina. SUBJECTS: Two thousand three hundred thirty-one students in the sixth, seventh, and eighth grades. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Responses to questions regarding weight control practices, including vomiting or laxative use, dieting, exercise, or diet pill use. RESULTS: Of the students surveyed, 110 (9.7%) of the girls and 46 (4.0%) of the boys reported vomiting or using laxatives to lose weight. Among the girls, vomiting or laxative use was associated with feeling overweight, other weight loss practices, older age, being a poor student, smoking, eating more salads or vegetables, and eating more candy or other sweets (P< or =.01). A logistic regression model consisting of diet pill use, dieting to lose weight, lower academic achievement, and currently trying to lose weight correctly classified 92% of female students who had or had not vomited or used laxatives. Among boys, vomiting or laxative use was associated with feeling overweight, other weight loss practices, minority racial status, smoking, frequency of eating hamburgers or other high-fat meats, and frequency of eating french fries or potato chips (P< or =.01). A model consisting of diet pill use, minority race, dieting to lose weight, smoking, feeling overweight, and number of servings of hamburgers, hot dogs, or barbecue correctly classified 97% of the boys who had or had not vomited or used laxatives. CONCLUSION: Younger adolescents trying to lose weight engage in a variety of problem dieting and weight loss behaviors that can compromise health and may be associated with eating disorders.     

Platelet-derived growth factor reverses the effects induced by NSAIDs on ulcer healing

BACKGROUND: It is known that non-steroidal anti-inflammatory drug (NSAID) use delays the healing of peptic ulcers and that growth factors play an important role in the ulcer healing process. AIM: To evaluate the effect of platelet-derived growth factor (PDGF) in healing chronic gastric ulcers in rats treated with NSAIDs. METHODS: Chronic gastric ulcers were induced with acetic acid in male Wistar rats and then treated with either aspirin (100 mg/kg/day), indomethacin (2 mg/kg/day), PDGF-BB (0.1 nM/kg/day) or combinations. Gastric secretion and ulcer size, wound contraction, mucosal regeneration and cell proliferation were assessed in histological specimens. RESULTS: Both aspirin and indomethacin delayed the healing rate of gastric ulcers and reduced ulcer contraction, mucosal regeneration and cell proliferation. All these effects were completely reversed by oral treatment with PDGF-BB without affecting gastric acid secretion. CONCLUSION: Oral administration of PDGF accelerates ulcer healing and reverses the effects induced by NSAIDs on ulcer healing without affecting gastric secretion.     

Intractable diarrhea. Intestinal perfusion studies and plasma VIP concentrations in patients with pancreatic cholera syndrome and surreptitious ingestion of laxatives and diuretics

Small-intestinal perfusion studies with a triple-lumen tube were performed in the jejunum and ileum of 11 patients with a presumptive diagnosis of pancreatic cholera syndrome (PCS). Ultimately PCS was proven to be present in only 3 patients, whereas 6 were discovered to be taking either laxatives or diuretics surreptitiously. In 2 of the 11 patients the cause of the diarrhea could not be determined. In PCS the major abnormality which we observed was that the jejunal mucosa secreted rather than absorbed when perfused with a plasma-like solution. By contrast, the ileum of the PCS patients absorbed a plasma-like solution in a normal fashion; however, one patient failed to absorb sodium and chloride when a solution with low (50 mM) sodium chloride concentration was perfused in the ileum. The volume of endogenous fluid was high in both the jejunum and ileum, presumably because of proximal small-intestinal secretion. Glucose stimulated sodium movement in an absorptive direction in each patient. Studies were repeated in one PCS patient after tumor removal, and his intestinal absorption of water and electrolytes was normal. Patients with diarrhea due to surreptitious ingestion of laxatives and diuretics showed normal absorption in the jejunum and ileum. This study shows that proximal small-bowel secretion was the major cause for diarrhea in our 3 patients with PCS. This cannot be a consequence of diarrhea per se since it was not found in patients with long-standing diarrhea due to surrepitious drug ingestion. Small-intestinal perfusion studies may be helpful in the diagnosis and management of selected cases of severe chronic diarrhea. On the other hand, measurement of plasma VIP concentration, especially by methods currently used in the United States, is of little use and may be misleading.     

Water supplementation enhances the effect of high-fiber diet on stool frequency and laxative consumption in adult patients with functional constipation

BACKGROUND/AIMS: The purpose of this study was to determine the effects of a high-fiber diet and fluid supplementation in patients with functional chronic constipation. METHODOLOGY: One hundred and seventeen patients with chronic functional constipation (aged 18-50 years) were randomly divided into two treatment groups. For two months both groups consumed a standard diet providing approximately 25 g fiber per day. Group 1 (58 patients) was allowed ad libitum fluid intake, while Group 2 was instructed to drink 2 liters of mineral water per day. Compliance was monitored throughout the study and results were assessed in terms of bowel-movement frequency and laxative use. RESULTS: Fiber intake was similar in the two groups, while total daily fluid intake in Group 2 (mean 2.1 liters) was significantly greater than that of Group 1 (1.1 liters)(p < 0.001). In both groups, there were statistically significant increases in stool frequency and decreases in laxative use during the two-month trial, but both changes were greater in Group 2 (stool frequency: p < 0.001 vs. Group 1; laxative use: p < 0.001 vs Group 1). CONCLUSIONS: A daily fiber intake of 25 g can increase stool frequency in patients with chronic functional constipation, and this effect can be significantly enhanced by increasing fluid intake to 1.5-2.0 liters/day.     

Charge distribution in Y1-xPrxBa2Cu3O7: A valency model for the depression of Tc

Indomethacin, a common non-steroidal anti-inflammatory drug (NSAID), has been used to treat rheumatoid arthritis. Although indomethacin has also been used as an immunopotentiator and symptomatic NSAID in AIDS, its effect on HIV replication is unknown. MT-4 lymphocytes were inoculated with HIV in the presence of indomethacin and tested for p24 expression by ELISA. The 50% inhibition (IC50) was 10 microM, corresponding to plasma levels after administration of 50 mg oral indomethacin. The antiviral effect appears to be specific since no toxicity has been observed at the IC50 dose, and unrelated NSAIDs have not shown the activity at clinical doses. Indomethacin may, thus, represent a new class of anti-HIV drug.     

Indomethacin-induced colonic ulceration and bleeding

OBJECTIVE: To report a case of nonsteroidal antiinflammatory drug (NSAID)-induced lower gastrointestinal (GI) bleeding. CASE SUMMARY: A patient in whom short-term ingestion of indomethacin was associated with colonic ulceration and significant gastrointestinal bleeding is described. DISCUSSION: The bleeding ulceration of the ascending colon, associated in our patient with short-term indomethacin intake, confirms previous reports of the drug's deleterious effect on the lower GI tract. The incidence of NSAID injury of the small intestinal colon may be higher than that previously reported. CONCLUSIONS: A prospective study of NSAID users could assess the magnitude of lower GI lesions, concomitant with upper GI evaluation, and help determine limitations in the use of this drug class.     

Independent modulation of horse airway smooth muscle by epithelium and prostanoids

The effects of epithelial removal and cyclooxygenase inhibition on contractions induced by exogenous acetylcholine (ACh) and electrical field stimulation (EFS) were evaluated in horse tracheal strips and bronchial rings. Epithelial removal potentiated the response to ACh but had no influence on the response to EFS. The effect of epithelial removal was not altered by pretreating the tissues with meclofenamate, a cyclooxygenase inhibitor. In trachealis strips, meclofenamate augmented contractions induced by EFS but not by ACh. In bronchial rings, meclofenamate augmented EFS-induced contraction to a greater extent than ACh-induced contraction. These effects of meclofenamate were epithelium-independent. We conclude that horse airway epithelium produces a relaxant factor that is not a prostanoid. Endogenous prostanoids originating from non-epithelial sites inhibit only cholinergic nerves in the trachea but both parasympathetic nerves and smooth muscle in the bronchi.     

Effects of cyclooxygenase-2 selective and nitric oxide-releasing nonsteroidal antiinflammatory drugs on mucosal ulcerogenic and healing responses of the stomach

Effects of selective cyclooxygenase-2 (COX-2) inhibitors (NS-398) and nitric oxide (NO) -releasing aspirin (NO-ASA) on gastric ulcerogenic and healing responses were examined in comparison with nonselective COX inhibitors such as indomethacin and aspirin (ASA). Hypothermic stress (28-30 degrees C, 4 hr) induced gastric lesions in anesthetized rats with an increase of acid secretion. The lesions induced by hypothermic stress were markedly worsened by subcutaneous administration of both indomethacin and ASA but were not affected by either NS-398 or NO-ASA, although the increased acid secretion during hypothermia was not affected by any of the drugs. On the other hand, the healing of gastric ulcers induced in mice by thermal cauterization (70 degrees C, 15 sec) was significantly delayed by daily subcutaneous administration of indomethacin and ASA as well as NS-398, but not by NO-ASA. COX-2 mRNA was not detected in the intact mucosa but was positively expressed in the ulcerated mucosa, most potently on day 3 after ulceration. Prostaglandin contents in the intact mouse stomach were reduced by indomethacin, ASA, and NO-ASA, while the increased prostaglandin generation in the ulcerated mucosa was inhibited by all drugs including NS-398. After subcutaneous administration of NO-ASA to pylorus-ligated rats and mice, high amounts of NOx were detected in both the gastric contents and serum. In addition, both NS-398 and NO-ASA showed an equipotent antiinflammatory effect against carrageenan-induced paw edema in rats as compared with indomethacin and ASA. These results suggest that both indomethacin and ASA not only increased the mucosal ulcerogenic response to stress but impaired the healing response of gastric ulcers as well. The former action was due to inhibition of COX-1, while the latter effect was accounted for by inhibition of COX-2 and was mimicked by the COX-2-selective inhibitor NS-398. NO-ASA, although it inhibited both COX-1 and COX-2 activity, had no deleterious effects on gastric ulcerogenic and healing responses.     

Pilot study of pathophysiology of constipation among community diabetics

We aimed to compare gastrointestinal transit and defecatory function in a random sample of people with or without diabetes mellitus in a US community who reported constipation or laxative use. In this pilot study we measured: gastric, small bowel, and colonic transit by scintigraphy; vector manometry of anal sphincters at rest and during squeeze; defecatory dynamics by balloon expulsion test; and scintigraphic measurement of anorectal angle at rest and during defecation. Autonomic function tests were performed in diabetics. Diabetics with constipation had a higher prevalence of abnormal evacuation or prolonged colonic transit during the first 24 hr than controls (P = 0.07): three had prolonged 24-hr colonic transit, and three abnormal evacuation. Among constipated controls, only one had anismus. Overall, diabetics had slower colonic transit during the first 24 hr than nondiabetics (P < 0.05). Community diabetics who experience constipation or use laxatives have a greater prevalence of delayed 24-hr colonic transit or evacuatory dysfunction than community controls.     

Surgery for asymptomatic carotid stenosis: a study of three patient subgroups

Increasing evidence suggests that non-steroidal anti-inflammatory drugs (NSAID) differ in gastrotoxicity. This study aimed to compare the effects of a short-acting NSAID, tiaprofenic acid, with indomethacin on experimental gastric ulcer healing in a rat model. Similar anti-inflammatory and prostaglandin-inhibitory doses of indomethacin (1 mg/kg) and tiaprofenic acid (2 mg/kg) were administered to rats with acetic acid-induced ulcers. After 2 weeks treatment, rats were killed and ulcer size determined. In addition, histological sections of ulcers were assessed for ulcer contraction and mucosal regeneration. The degree of inhibition of prostaglandin E2 (PGE2) synthesis was 72% at 2 h after tiaprofenic acid and 64% at 2 h after indomethacin administration, respectively. Rats treated with indomethacin for 2 weeks had significantly larger ulcers, both macroscopically and microscopically, than controls. Rats treated with tiaprofenic acid for 2 weeks had ulcers of a similar size to those of controls. Indomethacin-treated ulcers showed a failure in mucosal regeneration. Tiaprofenic acid-treated ulcers had significantly more regeneration than indomethacin-treated ulcers. We conclude that tiaprofenic acid inhibits mucosal prostaglandin levels but does not inhibit experimental gastric ulcer healing. These findings suggest that inhibition of PGE2 synthesis is not the only factor in generating gastrotoxicity and that a shift to low gastrotoxic NSAID may be clinically worthwhile.     

Clinical pharmacokinetics of diclofenac. Therapeutic insights and pitfalls

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) of the phenylacetic acid class. When given orally the absorption of diclofenac is rapid and complete. Diclofenac binds extensively to plasma albumin. The area under the plasma concentration-time curve (AUC) of diclofenac is proportional to the dose for oral doses between 25 to 150 mg. Substantial concentrations of drug are attained in synovial fluid, which is the proposed site of action for NSAIDs. Concentration-effect relationships have been established for total bound, unbound and synovial fluid diclofenac concentrations. Diclofenac is eliminated following biotransformation to glucoroconjugated and sulphate metabolites which are excreted in urine, very little drug is eliminated unchanged. The excretion of conjugates may be related to renal function. Conjugate accumulation occurs in end-stage renal disease; however, no accumulation is apparent upon comparison of young and elderly individuals. Dosage adjustments for the elderly, children or for patients with various disease states (such as hepatic disease or rheumatoid arthritis) may not be required. Significant drug interactions have been demonstrated for aspirin (acetylsalicylic acid), lithium, digoxin, methotrexate, cyclosporin, cholestyramine and colestipol.     

The role of endogenous nitric oxide in the gastroprotective action of morphine

Morphine in a dose of 1 mg/kg s.c. decreased mucosal lesions induced by 100% ethanol or acidified aspirin by 79% and 85%, respectively, in rats. When the animals were pretreated with NG-nitro-L-arginine (40 mg/kg i.v.), the mucosal lesions were aggravated in both tests and the gastroprotective action of morphine decreased to 17% and 20%, respectively. This decrease in morphine protection was antagonized by L-arginine but not by D-arginine in the case of ethanol-induced lesions; however, L-arginine failed to restore the gastroprotective effect of morphine when the mucosal damage was induced by acidified aspirin. The protective action of either prostaglandin E2 (0.1 mg/kg orally) or cysteamine (50 mg/kg orally) was not influenced by NG-nitro-L-arginine (L-NNA). When L-NNA was given simultaneously with either indomethacin (10 mg/kg p.o.) or N-ethyl-maleimide (50 mg/kg s.c.), compounds which also reduced the gastroprotective action of morphine, almost complete inhibition of the gastroprotective action of morphine against 100% ethanol-induced lesions was observed as a result of the addition of the inhibitory activities of the latter substances. These results suggest that: (1) Endogenous nitric oxide is likely to be involved in the gastroprotective action of morphine. (2) The protective action of nitric oxide is independent of both mucosal prostaglandins and sulfhydryls.     

Efficacy of famotidine in the healing of active benign gastric ulceration: comparison of nonsteroidal anti-inflammatory- or aspirin-induced gastric ulcer and idiopathic gastric ulceration. Long Island Jewish Medical Center Acid-Peptic Study Group

Seventy-one of 85 consecutive patients with endoscopically confirmed active benign gastric ulcers completed an 8-week study to evaluate the effects on healing of famotidine 40 mg given as a single dose at night. The healing rate in the 48 patients in whom the ulcers were associated with nonsteroidal anti-inflammatory drug (NSAID) or aspirin (ASA) use was compared with that in the 23 patients with idiopathic ulcers. Endoscopy, symptom assessments, antacid use, hematology, and serum chemistry were performed at weeks 4 and 8 of treatment. Famotidine 40 mg at bedtime healed 63 (89%) of the 71 ulcers at 8 weeks; the healing rate for NSAID/ASA-associated ulcers was 46 (96%) of 48, which was significantly greater than that for idiopathic ulcers (17 of 23; 74%) (P = 0.0119). Of the 54 patients who returned a questionnaire 1 to 2 years after completing the study, 20% were still taking an NSAID/ASA (mainly for cardiovascular prophylaxis). About half of the patients surveyed were taking anti-ulcer medication. None of these patients had experienced any serious ulcer complication. The results of this study suggest that differentiating NSAID/ASA-induced ulcers from idiopathic ulcers may be important with regard to healing rates and duration of therapy.