Prednisolone absorption in acute colitis

Impact of Inflammatory Bowel Disease (IBD) and IBD Medications on Risk of Hyperlipidemia and in vitro Hepatic Lipogenic-Related Gene Expression: A Population-Based Cohort Study

Patients with inflammatory bowel disease (IBD) present a higher risk of developing cardiovascular diseases (CVDs) due to chronic inflammation, which plays an essential role in atherogenesis. Hyperlipidemia is another risk factor for CVDs; however, the association between IBD, IBD medications, and hyperlipidemia remains controversial. We conducted a nationwide, population-based, retrospective, cohort study to examine the effect of IBD and IBD medications on the risk of developing hyperlipidemia. The effects of IBD medications on the expression of lipogenesis-related hepatic genes were also evaluated. We obtained data from the Longitudinal Health Insurance Database of Taiwan from patients with new-onset IBD and a comparison cohort of patients without IBD. A Cox proportional hazards regression model was used to analyze the difference in the risk of developing hyperlipidemia between the two cohorts. We also examined the influence of IBD medications on the expression of lipogenesis-related hepatic genes. After adjusting for comorbidities and confounding factors, the case group (N = 14,524) had a higher risk for hyperlipidemia than the control group (N = 14,524) [adjusted hazards ratio (aHR), 2.18]. Patients with IBD that did not receive IBD medications exhibited a significantly higher risk of hyperlipidemia (aHR, 2.20). In those treated with IBD medications, the risk of developing hyperlipidemia was significantly lowered than those without such medications (all aHR ≤ 0.45). Gene expression analysis indicated that IBD medications downregulated the expression of lipogenesis-related genes. Screening blood lipids in IBD patients is needed to explore the specific role and impact of IBD medications in the development of CVD.

Outpatient management of inflammatory bowel disease

Inflammatory bowel disease is a conglomeration of disorders of unclear etiology and pathogenesis. Confirming the diagnosis of active disease may be difficult but is critical to judicious therapy. Sulfasalazine (Azulfidine) and its newer derivatives mesalamine (Asacol, Rowasa) and olsalazine sodium (Dipentum) are used for treatment of mild disease and maintenance. Corticosteroid therapy controls moderate disease in most patients, but withdrawal may be difficult. Immunosuppression or surgery may be necessary in severe or refractory cases. The risk of cancer as a complication of inflammatory bowel disease is often exaggerated but cannot be ignored.

Intravenous corticosteroids in moderately active ulcerative colitis refractory to oral corticosteroids

BACKGROUND

Oral corticosteroids remain the mainstay of treatment for moderately active ulcerative colitis (UC). In patients who fail to respond to oral corticosteroids, attempting the intravenous route before starting rescue therapies is an alternative, although no evidence supports this strategy.

AIM

To evaluate clinical outcomes after a course of intravenous corticosteroids for moderate attacks of UC according to the failed oral corticosteroids or not.

METHODS

All episodes of active UC admitted to three university hospitals between January 2005 and December 2011 were identified and retrospectively reviewed. Only moderately active episodes treated with intravenous corticosteroids were included. Treatment outcome was compared between episodes which failed to outpatient oral corticosteroids for the index flare and those directly treated by intravenous corticosteroids.

RESULTS

110 episodes were included, 45% of which failed to outpatient oral corticosteroids (median dose 60mg/day [IQR 50-60], median length of course 10days [IQR 7-17]). Initial response (defined as mild severity or inactive disease at day 7 after starting intravenous corticosteroids, without rescue therapy) was achieved in 75%, with no between-group differences (78% vs. 75%). After a median follow-up of 12months (IQR 4-24), 35% of the initial responders developed steroid-dependency and up to 13% required colectomy. Unsuccessful response to oral corticosteroids was the only factor associated with steroid-dependency in the long term (P=0.001).

CONCLUSIONS

Intravenous corticosteroids are efficient for inducing remission in moderately active UC unresponsive to oral corticosteroids, but almost half of these patients develop early steroid-dependency. Alternative therapeutic strategies should be assessed in this clinical setting.

Clinical outcomes and predictive factors in oral corticosteroid-refractory active ulcerative colitis

AIM: To evaluate the clinical outcomes and prognostic factors after intravenous corticosteroids following oral corticosteroid failure in active ulcerative colitis patients.

METHODS: Consecutive patients with moderate to severe ulcerative colitis who had been treated with a course of intravenous corticosteroids after oral corticosteroid therapy failure between January 1996 and July 2010 were recruited at Severance Hospital, Seoul, South Korea. The disease activity was measured by the Mayo score, which consists of stool frequency, rectal bleeding, mucosal appearance at flexible sigmoidoscopy, and Physician Global Assessment. We retrospectively evaluated clinical outcomes at two weeks, one month, three months, and one year after the initiation of intravenous corticosteroid therapy. Two weeks outcomes were classified as responders or non-responders. One month, three month and one year outcomes were classified into prolonged response, steroid dependency, and refractoriness.

RESULTS: Our study included a total of 67 eligible patients. At two weeks, 56 (83.6%) patients responded to intravenous corticosteroids. At one month, complete remission was documented in 18 (32.1%) patients and partial remission in 26 (46.4%). Eleven patients (19.7%) were refractory to the treatment. At three months and one year, we found 37 (67.3%) and 25 (46.3%) patients in prolonged response, ten (18.2%) and 23 (42.6%) patients in corticosteroid dependency, 8 (14.5%) and 6 (11.1%) patients with no response, respectively. Total 9 patients were underwent elective proctocolectomy within 1 year. The duration of oral corticosteroid therapy (> 14 d vs≤ 14 d, P = 0.049) and lower hemoglobin level (≤ 11.0 mg/dL vs >11.0 mg/dL, P = 0.02) were found to be poor prognostic factors for response at two weeks. For one year outcome, univariate analysis revealed that only a partial Mayo score (≥ 6 vs <6, P = 0.057) was found to be associated with a poor response.

CONCLUSION: The duration of oral corticosteroid therapy and lower hemoglobin level were strongly associated with poor outcome.

Long-term outcome of ulcerative colitis in patients who achieve clinical remission with a first course of corticosteroids

BACKGROUND

Although the early outcomes of ulcerative colitis after a first course of corticosteroids are well known, data on long-term disease evolution in patients responding to a first corticosteroid course are scarce.

AIMS

To evaluate the long-term clinical evolution in ulcerative colitis patients responding to a first course of corticosteroids and to identify those factors associated with a poorer outcome.

METHODS

Retrospective review of 114 patients diagnosed with ulcerative colitis who responded to the first corticosteroid course, and did not start thereafter maintenance therapy with thiopurines were included.

RESULTS

Corticosteroids were prescribed because of a moderate (78%) or a severe flare (22%). All but two patients followed maintenance treatment with mesalazine after corticosteroid discontinuation. After a median follow-up of 83 months (7-156), 72% of patients suffered new relapses leading to corticosteroid reintroduction in 65% of patients. The earlier corticosteroids were introduced in the course of ulcerative colitis, the higher the risk of relapse and corticosteroid reintroduction. Thiopurines were started in 51%, and infliximab in 19%. Eleven percent of patients underwent colectomy. No predictors of thiopurine use or colectomy were found.

CONCLUSIONS

Half of the ulcerative colitis patients responding to a first course of corticosteroids will require immunosuppressors mainly because of steroid-dependence.

Severe ulcerative colitis: At what point should we define resistance to steroids?

Corticosteroids are still the first-line treatment for active ulcerative colitis more than 50 years after the publication of trials assessing their beneficial effect, with about a 50% remission rate in cases of severe disease. The mortality related to severe attacks of ulcerative colitis has decreased dramatically, to less than 1%, in experienced centers, due to the appropriate use of intensive therapeutic measures (intravenous steroids, fluids and electrolytes, artificial nutritional support, antibiotics, etc), along with timely decision-making about second-line medical therapy and early identification of patients requiring colectomy. One of the most difficult decisions in the management of severe ulcerative colitis is knowing for how long corticosteroids should be administered before deciding that a patient is a non-responder. Studies assessing the outcome of acute attacks after steroid initiation have demonstrated that, in steroid-sensitive patients, the response generally occurs early on, in the first days of treatment. Different indexes to predict treatment failure, when applied on the third day of treatment, have demonstrated a high positive predictive value for colectomy. In contrast to this resolute approach, which is the most widely accepted, other authors have suggested that in some patients a complete and prolonged response to steroids may take longer. Either way, physicians taking care of these patients need to recognize that severe ulcerative colitis may be life-threatening, and they need to be careful with excessively prolonged medical treatment and delayed surgery.

Characterization of epithelial IL-8 response to inflammatory bowel disease mucosal E. coli and its inhibition by mesalamine

BACKGROUND

Mucosally adherent E. coli are found in inflammatory bowel disease (IBD) and colon cancer. They promote release of the proinflammatory cytokine interleukin-8 (IL-8). We explored mechanisms for this release and its inhibition by drugs.

METHODS

IL-8 release from colon epithelial cells in response to mucosal E. coli isolates from IBD, colon cancer, and controls was characterized at the cellular and molecular level.

RESULTS

IL-8 response of HT29 cells was greater with Crohn's disease (689 +/- 298 [mean +/- SD] pg IL-8/mL at 4 hours, n = 7) and colon cancer isolates (532 +/- 415 pg/mL, n = 14) than with ulcerative colitis (236 +/- 58 pg/mL, n = 6) or control isolates (236 +/- 100 pg/mL, n = 6, P < 0.0001). Bacterial supernatants contained shed flagellin that triggered IL-8 release. For whole bacteria the IL-8 response to E. coli that agglutinate red blood cells (548 +/- 428 pg IL-8/mL, n = 16), a function that correlates with epithelial invasion, was greater than for nonhemagglutinators (281 +/- 253 pg/mL, n = 17; P < 0.0001). This was particularly marked among E. coli that, although flagellate, could not release IL-8 from TLR5-transfected HEK293 cells. IL-8 release was mediated by extracellular-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) and inhibited by mesalamine, but not hydrocortisone, at therapeutic concentrations.

CONCLUSIONS

Mucosa-associated E. coli shed flagellin that elicits epithelial IL-8 release but this may only become relevant when the mucosal barrier is weakened to expose basolateral TLR5. Adherent and invasive IBD and colon cancer E. coli isolates also elicit a flagellin-independent IL-8 response that may be relevant when the mucosal barrier is intact. The IL-8 release is MAPK-dependent and inhibited by mesalamine.

Review article: systemic and topical steroids in inflammatory bowel disease

Steroids are still widely used in the treatment of inflammatory bowel diseases. Pharmacological studies have shown that there is no major abnormality in the pharmacokinetics of steroids in these disorders. Foam preparations with rectal application decrease the bioavailability to low levels, eliminating systemic complications. For oral use, 'nonsystemic' steroids have been developed. In ulcerative colitis, steroids are rarely needed as 5-aminosalicylates are effective in the majority of patients. This is true for rectal application in distal colitis, as well as in more extensive disease. In Crohn's disease, steroids are more often used; however, in population-based studies, less than 50% of patients have been treated with steroids, as there are alternative treatments available for the large group of patients with mild to moderate activity. For those patients needing steroid treatment, budesonide seems to be a good choice in active disease, but has not shown convincing effects in the maintenance of remission over longer periods of time. There is no place for long-term steroid treatment in ulcerative colitis and very little in Crohn's disease--immunosuppression with azathioprine or related drugs is certainly the better alternative.

Medical treatment of ulcerative colitis

Ulcerative colitis is a chronic inflammatory disease of the colon with an increasing incidence worldwide. The medical management of this disease continues to expand as drugs to induce and maintain remission are sought to avoid the need for colectomy. This article will review the standard of care for the treatment of mild, moderate, and severe ulcerative colitis. The efficacy, optimal usage, and adverse events profile of agents such as 5-aminosalicylates, corticosteroids, azathioprine, and cyclosporine will be discussed and an algorithm for their use will be developed. Alternative and experimental therapies such as monoclonal antibodies, probiotics, and heparin will also be addressed.

Influence of prednisolone on the secretion of mucin from the HT29-MTX cell line

Glucocorticoids have been used in the treatment of otitis media with effusion with promising but inconsistent results. The HT29-MTX cell line is a completely differentiated and almost exclusively mucus-secreting goblet cell line. To assess the potential of steroids in suppressing mucin secretion, we have studied the response of this cell culture to prednisolone. Confluent cell cultures were trypsinized, subcultured in six-well plates and incubated with five doses of prednisolone from 10-3 M to 10-11 M and over a varying time course from 6 to 36 h. Analysis was performed using a monoclonal mouse antibody to human gastric mucin by dot-blot ELISA. Prednisolone caused a consistent reduction in mucin production from this cell line. Increasing concentrations of prednisolone resulted in increasing suppression of MUC5AC secretion. There is a dose-dependent suppression of mucin secretion by prednisolone, with a maximum effect of 21% over control seen at the highest steroid concentration used.

Management of acute severe colitis

Early identification of patients with acute severe colitis is essential so that prompt treatment can be instigated. Corticosteroids have remained the mainstay of treatment since 1955. The introduction of ciclosporin into the pharmacological armamentarium has reduced early colectomy rates but even with modern medical management up to 30% of patients will still undergo colectomy on the same admission. The overall mortality is now less than 1% in specialist centres compared to 30% in the pre-steroid era. The future promises further advances in treatment through medications that are targeted directly at the underlying inflammatory process.

Clinical evaluation and management of acute severe colitis

This review concentrates on the clinical evaluation, imaging, therapy, and prognostic factors in acute severe colitis of idiopathic as well as infectious origin. Older concepts as well as more recent are critically scrutinized.

Colonoscopy of acute colitis. A safe and reliable tool for assessment of severity

Complications that might lead to surgery in severe attacks of ulcerative colitis have been found to be correlated with the depth of colonic ulcerations as measured by pathological examination of colectomy specimens. In order to evaluate the value of colonoscopy for the assessment of colonic ulcerations, we have reviewed the clinical, biological, colonoscopic, and anatomical findings in 85 consecutive patients with attacks of ulcerative colitis involving at least the rectosigmoid and part of the descending colon, seen in our center between 1981 and 1989. All had colonoscopy performed by a senior endoscopist at entry. Extensive deep colonic ulcerations were diagnosed in 46 of them, and moderate endoscopic colitis in 39. No complication related to colonoscopy occurred except for one colonic dilatation. Forty-three of the 46 patients with severe endoscopic colitis were operated upon; 38 of them failed to improve with high-dose corticosteroids and five had a toxic megacolon. Extensive ulcerations reaching at least the circular muscle layer were found at pathological examination of colectomy specimen in 42 of the 43 patients. Conversely, 30 of 39 patients with moderate endoscopic colitis went into clinical remission with medical treatment, and only nine patients needed further surgery because of medical treatment failure. Six of these nine patients underwent another colonoscopy prior to colectomy, and all six showed features of severe endoscopic colitis. Deep ulcerations reaching the circular muscle layer were found at pathological examination in five of these six patients and in one additional patient whose colonoscopy had been performed 21 days before colectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of ulcerative colitis with high doses of oral prednisolone. The rate of remission, the need for surgery, and the effect of prolonging the treatment

Treatment of acute attacks of ulcerative colitis in 89 patients with doses of prednisolone above or equal to 40 mg resulted in an overall remission in 67%. Remission rate and colectomy rate were 47% and 42%, respectively, when the disease was severe, 80% and 13% when moderate, and 84% and 3% when mild. The need for surgery was 28% in pancolitis, 11% in left-sided colitis, and 5% in proctitis. After subsequent treatment episodes colectomy was performed in 35% of patients with pancolitis, in 37% with left-sided colitis, and in 5% with proctitis. The median total duration of therapy in patients who went into clinical remission was 4 months, and the median dose just above 3 g prednisolone. Patients who stayed in remission during the follow-up received a significantly higher start dose and total dose of prednisolone in the treatment episode than patients who had a relapse. In 25 patients treatment with doses equal to or above 75 mg of prednisolone was continued beyond 10 days, and 11 patients experienced remission whereas 14 patients had surgery performed. Orally administered corticosteroids produce results comparable to those obtained after the previously suggested intravenous regimen.

Pharmacokinetics of budesonide enema in patients with distal ulcerative colitis or proctitis

Pharmacokinetic data obtained after one dose of a 2-mg budesonide enema were compared with data obtained after the last dose of four weeks of daily treatment in 24 patients with active distal ulcerative colitis or proctitis. This open multicentre study involved 28 eligible patients. Sigmoidoscopy and biopsy scores improved significantly (P < 0.002) during the four-week treatment period. Maximal plasma concentration (Cmax) of budesonide was 2.1 nmol/L 1.3 h after the first dose and 2.5 nmol/L 1.2 h after the last dose; the difference was not significant. The area under the curve (AUC) of plasma concentration vs. time was after the first dose 9.7 nmol h/L and after the last dose 11.6 nmol h/L (P < 0.03). The small increase in AUC may be attributed to improved absorption. During the last dose interval, minimal plasma concentration was below the limit of quantitation in most subjects. The Cmax and AUC of budesonide increased slightly after four weeks of treatment, but budesonide did not accumulate. Mean morning plasma cortisol values did not change significantly during treatment (P = 0.083), although a small change in cortisol levels between the first visit (pre-treatment) and last visit was positively correlated to the Cmax of budesonide measured at the last visit (P = 0.012).

Drug absorption in gastrointestinal disease and surgery. Clinical pharmacokinetic and therapeutic implications

Drug absorption from the gastrointestinal (GI) tract and the impact of GI surgery and disease on drug absorption are discussed. Recommendations are made to manage problems of drug malabsorption. Absorption from the GI tract is a first-order process described by its rate and extent. GI surgery changes the anatomy of the GI tract and alters important variables in the absorption process. In the wake of procedures which diminish small bowel surface area, the extent of absorption of phenytoin, digoxin, cyclosporin, aciclovir, hydrochlorothiazide and certain oral contraceptives is reported to be reduced. The underlying cause of the reduction is unknown. When gastric emptying time or pH are altered by surgery, the rate of drug absorption appears to be reduced. However, it is not clear which variable is more important in determining therapeutic effects. The effects of coeliac and inflammatory bowel diseases on the distribution and clearance of drugs must be considered before attributing abnormal serum concentrations of drugs to malabsorption. GI disease may slow gastric emptying and delay the complete absorption of drugs when their rate of absorption depends on gastric emptying time. Other inflammatory GI diseases such as graft-versus-host disease (GVHD) of the gut, Behçet's syndrome and scleroderma involving the GI tract may directly reduce absorption of drugs such as cyclosporin, amitriptyline, benzodiazepines, anticonvulsants, paracetamol (acetaminophen) and penicillamine. GI diseases which alter gut pH affect the absorption only of drugs with limited water solubility and pH-dependent dissolution such as ketoconazole. Clinicians should be aware of the variable absorption seen after GI disease and surgery and monitor their patients accordingly.

Clinical pharmacokinetics of prednisone and prednisolone

The growth of knowledge in the field of the pharmacokinetics of prednisolone/prednisone has been slow for several reasons. First, convenient and specific methods for measuring these steroids only became available with the development of high performance liquid chromatographic methods. Secondly, prednisolone is nonlinearly bound to transcortin and albumin: since the unbound concentrations of prednisolone are biologically relevant, it was necessary to determine the free fraction in each plasma sample. Thirdly, due to the short half-life of prednisolone no steady-state is achieved, and therefore area under the concentration-time curve needed to be determined in all studies. Fourthly, prednisolone and prednisone are interconvertible and prednisolone is given intravenously as an ester prodrug, features which created controversies about the correct interpretation of pharmacokinetic results. Finally, the total body clearances of total and (to a lesser degree) of unbound prednisolone increase with increasing concentrations of prednisolone. Therefore, in order to compare pharmacokinetic results between different subjects, standardised doses had to be administered. The investigations performed so far have revealed that: (1) the dose-dependent pharmacokinetics partly explain the clinical observation that an alternate-day regimen with prednisone yields fewer biological effects; (2) the interconversion of prednisone into prednisolone is not a limiting factor, even in patients with severely impaired liver function; (3) hypoproteinaemia per se does not cause increased unbound concentrations of prednisolone in vivo; (4) patients with liver failure, renal failure or a renal transplant, subjects older than 65 years, women on estrogen-containing oral contraceptive steroids or subjects taking ketoconazole have increased unbound concentrations of prednisolone-whereas hyperthyroid patients, some patients with Crohn's disease, subjects taking microsomal liver enzyme-inducing agents or patients on intravenous prednisolone phthalate (instead of prednisolone phosphate) or on some brands of enteric coated prednisolone tablets have decreased concentrations of prednisolone. The biological relevance of the altered pharmacokinetics is supported in part by altered clinical effects and altered effects on cellular immunofunctions.

Drug absorption in gastrointestinal disease and surgery

It is well recognized that drug absorption from the gastrointestinal tract is influenced by gastric and intestinal motility, surface area available for absorption, and physicochemical properties of the drug. Disease and surgery have been shown to alter these factors. Consequently, drug absorption can be altered as well, and these affect drug therapy. Apparently this effect is variable, but the variability may be due in part to the complexities of performing studies in this area. For example, many patient factors as well as drug characteristics must be considered. In addition, appropriate interpretation of results requires that intravenous data be collected if changes in absorption are based on bioavailability. At this time, the alterations in drug absorption due to gastrointestinal disease and surgery are of unknown or little clinical significance; nevertheless, clinicians should be aware that the possibility of malabsorption exists and anticipate any monitoring of or alterations in therapy that may have to be made.

Prednisolone absorption in inflammatory bowel disease: correlation with anatomical site and extent

Prednisolone absorption was studied in 13 normal subjects, eight patients with ulcerative colitis and 21 patients with Crohn's disease, by measuring plasma levels after a single oral dose. Absorption of the drug was delayed in all patient groups. The peak plasma level of the drug was lower in patients with extensive small bowel Crohn's disease. Patients in this category may need higher doses of oral prednisolone than other patients with inflammatory bowel disease.

Persistent 24-h variations of urinary 6-hydroxy melatonin sulphate and cortisol in Antarctica

Bright light (2000-3000 lux) of sufficient intensity to suppress human melatonin secretion, acts as a strong zeitgeber in the entrainment of circadian rhythms in man. In polar conditions, light of this intensity is not experienced for several weeks during the winter. The entrainment of human circadian rhythms, in particular that of melatonin, is clearly of interest in these circumstances. Urinary 6-hydroxy melatonin sulphate (aMT6s) is a good index of melatonin secretion in man. In a limited study of seven male volunteers living on an Antarctic base the overall 24-h rhythm of aMT6s excretion was maintained at four different times of year (spring, summer, autumn and winter) and no significant seasonal effects were noted. Cortisol excretion, appeared to be markedly affected by the season although other factors such as social and environmental stress cannot be discounted. These observations suggest that in the absence of a strong light-dark cycle melatonin production may be entrained by other factors.

Plasma levels and response to prednisolone therapy in rheumatoid arthritis

Plasma prednisolone levels were measured in parallel with clinical and laboratory assessments in seven patients with rheumatoid arthritis on single daily doses of prednisolone which were reduced at weekly intervals from 10 mg. to 7, 6 and 5 mg. A significant negative rank correlation was observed between prednisolone dose and the duration of morning stiffness (p less than 0.05). No significant correlation was observed between plasma prednisolone levels, other clinical assessment criteria or laboratory indices.

Drug therapy of inflammatory bowel disease

Although the etiology of inflammatory bowel disease is unknown and specific therapy is unavailable, enough information on existing empiric agents is available to allow rational therapy. These agents include sulfasalazine, steroids, immunosuppressive drugs, metronidazole and cholestyramine. Sulfasalazine is a two-part molecule that depends on bacterial cleavage in the colon to deliver locally acting 5-aminosalicylate, whose mechanism of action may relate to inhibition of prostaglandin synthesis. The other half of the molecule, sulfapyridine, is responsible for most of the side effects of the drug. While the efficacy of sulfasalazine in the treatment and prevention of attacks of ulcerative colitis is well established, its use in Crohn's disease appears to be limited to patients with active colitis and ileo-colitis. Sulfasalazine is of major benefit in preventing relapses in patients with ulcerative colitis in remission. New formulations of 5-aminosalicylate may allow delivery of the apparently active moiety to the small bowel and colon without concomitant sulfapyridine toxicity. Corticosteroids are highly effective in acute attacks of ulcerative colitis and Crohn's ileitis and ileo-colitis; the mechanism of antiinflammatory action remains speculative. However, maintenance therapy with steroids is ineffective in preventing relapses or recurrent attacks of either ulcerative colitis or Crohn's disease. Steroid enemas allow topical administration to patients with distal colitis and proctitis with few systemic side effects. In children with growth failure associated with active Crohn's disease, amelioration by steroid therapy may actually restore normal growth. Immunosuppressive agents such as azathioprine and 6-mercaptopurine are of little value in active Crohn's disease when administered alone; however, in combination with other agents they may help diminish steroid dose, close fistulae and prevent relapse. Their mode of action likely depends on long-term cytostatic effects on immune effector cells. Concern for leukopenia and the development of late malignancy has limited their use to patients not responding to other therapies. Metronidazole, an antimicrobial agent that is effective against anaerobes, has recently been shown useful in Crohn's disease involving the colon and perianal area. Its mechanism of action is uncertain, but may be related to its antibacterial actions on anaerobes. Cholestyramine can be successfully used to control bile salt-induced diarrhea in Crohn's patients with terminal ileal resections. Effective drug therapy of inflammatory bowel disease is only part of a total program of management including reassurance, frequent explanation, well-timed use of surgery, and an understanding physician.

Plasma prednisolone studies in rheumatic patients

Prednisolone concentration in plasma after a daily maintenance steroid dose was monitored in 83 patients with rheumatic diseases. Although no restrictions were imposed on the intake of food or drink, plasma drug levels tended to peak at 1 h after the ingestion of the standard tablets, whereas intestinal absorption of the enteric-coated preparation was found to be most unpredictable. A profound individual variation was observed in plasma prednisolone concentrations, and neither total nor unbound drug levels showed any consistent relationship with the size of the prednisolone dose or the control of the disease activity. The basal cortisol production was suppressed in one-third of the patients. There is no support from this study for the concept of an 'optimum therapeutic range' of plasma prednisolone for the treatment of rheumatic disease.

Effect of inflammatory bowel disease on absorption and disposition of prednisolone

The pharmacokinetics and bioavailability of prednisolone after doses of oral prednisone and intravenous prednisolone were determined in seven patients receiving corticosteroids for treatment of inflammatory bowel disease in active disease and remission. Prednisone absorption and conversion to the active form of prednisolone was complete in both disease phases. Pharmacokinetic parameters for total and free (unbound) prednisolone did not differ significantly between disease phases. Differences in protein binding were observed between active disease and remission with the fractional binding of prednisolone to plasma proteins decreased in active disease. This may be accounted for by decreased plasma albumin concentrations in active disease. Alpha 1-acid glycoprotein concentrations were significantly higher in active disease but did not contribute to the overall binding of prednisolone.

Plasma prednisolone levels during intravenous therapy in acute colitis

Maximum plasma levels in six acute colitics were about three times greater after an intravenous bolus of 20 mg prednisolone than the mean level achieved during infusion of the same dose (p<0.001) over eight hours; the level during infusion was about twice as great as the maximum recorded previously after a single 40 mg oral dose of prednisolone. These findings favour the use of intravenous administration in severe acute colitis. No difference was found between plasma levels of patients and six normal subjects after the intravenous bolus.

Alteration of plasma prednisolone levels by indomethacin and naproxen

Eleven patients with stable rheumatoid disease (RD) who were receiving regular corticosteroid therapy (CS) were investigated to discover the effect on plasma prednisolone levels of additional therapy with the non-steroidal anti-inflammatory (NSAI) drugs, indomethacin and naproxen. There was a highly significant (P less than 0.001) increase in free prednisolone levels after concurrent therapy with either indomethacin or naproxen for 2 weeks. Total prednisolone levels were unchanged. These results could provide an explanation for clinical reports that these two NSAI drugs possess a steroid-sparing effect.

24-hour profiles of melatonin, cortisol, insulin, C-peptide and GIP following a meal and subsequent fasting

Melatonin, free and total cortisol, insulin, C-peptide and glucose-dependent insulin-releasing peptide (GIP) were measured in the plasma of twelve normal volunteers (eight women and four men), at hourly intervals for 24 h following a meal and subsequent fasting. One volunteer was excluded from calculations due to a possible effect of stress on melatonin secretion. Melatonin and cortisol showed the normal 24-h variation with peak values at 0200-0500 h, and 0900 h respectively. Following post-prandial stimulation, gut hormones remained basal throughout the sampling period. No significant relationship was found between 24-h melatonin secretion and basal, or stimulated gut hormone secretion. Melatonin secretion did relate significantly to body weight, suggesting that data concerning pineal effects in endocrine physiology and pathology, and affective disease, should be reviewed in the light of these observations.

Effect of prednisolone on prostaglandin synthesis by rectal mucosa in ulcerative colitis: investigation by laminar flow bioassay and radioimmunoassay

The effect of two concentrations of prednisolone on synthesis of prostaglandin E2 (PGE2) by 40 rectal biopsies in organ culture was investigated using both laminar flow bioassay and radioimmunoassay (RIA). Prednisolone (concentration 8.33 x 10(-7)M) reduced mean synthesis of PGE2 to 36.4% of control values (measured by bioassay) or 26.2% of control values (measured by RIA). With prednisolone (concentration 5.66 X 10(-4) M) synthesis of PGE2 was 7.7% of control values (RIA). The two concentrations are similar respectively to those achieved in plasma after oral prednisolone and delivered topically by prednisolone enemata. Inhibition of PG synthesis may thus explain prednisolone's anti-inflammatory action in the treatment of ulcerative colitis.

Prednisolone concentrations in plasma, saliva and urine

Prednisolone was measured in plasma, saliva and urine at various times after a single dose. Peak plasma prednisolone levels were observed about 1 h after the dose. Saliva prednisolone levels were measurable for at least 3 h after dosing but showed no consistent relationship to either total or free plasma prednisolone concentrations. Unchanged prednisolone in amounts up to 14% of the dose administered was found in the 24 h urine and most of it was excreted in the first 5 h.