Evaluation of the renal protective effect of misoprostol in elderly, osteoarthritic patients at risk for nonsteroidal anti-inflammatory drug-induced renal dysfunction

Minimizing risks of NSAIDs: cardiovascular, gastrointestinal and renal

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in treating inflammation, pain and fever, but their cardiovascular, renal and gastrointestinal toxicity can result in significant morbidity and mortality to patients. Techniques for minimizing the adverse risks of NSAIDs include avoiding use of NSAIDs where possible, particularly in high-risk patients; keeping NSAID dosages low; prescribing modified-release and enteric-coated NSAIDs; prescribing cyclooxygenase-2-selective inhibitors where appropriate; monitoring for early signs of side effects; prescribing treatments designed to minimize NSAID side effects; and developing new therapeutic strategies beyond the inhibition of cyclooxygenase. All of the above strategies can be useful in reducing the risk of NSAID complications. The optimal use and management of NSAIDs involves an individualized paradigm approach to establish efficacy with optimal tolerability given the patient risk factors for adverse events.

Misoprostol therapeutics revisited

Misoprostol, a prostaglandin E1 analog, is a racemate of four stereoisomers. On administration it rapidly de-esterifies to its active form, misoprostolic acid. Misoprostolic acid is 85% albumin bound and has a half-life of approximately 30 minutes. It is excreted in urine as inactive metabolites. No significant drug interactions have been reported. Besides its gastrointestinal protective and uterotonic activities, misoprostol regulates various immunologic cascades. It inhibits platelet-activating factor and leukocyte adherence, and modulates adhesion molecule expression. It protects against gut irradiation injury, experimental gastric cancer, enteropathy, and constipation. It improves nutrient absorption in cystic fibrosis. Misoprostol has utility in acetaminophen and ethanol hepatotoxicity, hepatitis, and fibrosis. It is effective in asthmatics and aspirin-sensitive asthmatic and allergic patients. It lowers cholesterol and severity of peripheral vascular diseases, prolongs survival of cardiac and kidney transplantation, synergizes cyclosporine, and protects against cyclosporine-induced renal damage. It works against drug-induced renal damage, interstitial cystitis, lupus nephritis, and hepatorenal syndrome. It is useful in periodontal disease and dental repair. Misoprostol enhances glycosoaminoglycan synthesis in cartilage after injury. It prevents ultraviolet-induced cataracts and reduces intraocular pressure in glaucoma and ocular hypertension. It synergizes antiinflammatory and analgesic effects of diclofenac or colchicine and has been administered to treat trigeminal neuralgic pain. It reduces chemotherapy-induced hair loss and recovery time from burn injury, and is effective in treating sepsis, multiple sclerosis, and pancreatitis.

Selected drug complications and treatment conflicts in the presence of coexistent diseases

The presence of different coexistent systemic diseases often times complicates the selection of the appropriate treatment of an underlying rheumatologic condition. In this article, some controversial treatment conflicts that are frequently encountered in the daily practice of rheumatology are clarified and guidelines for the best available therapeutic options are provided.

Prostaglandin E1 analogs do not improve renal function among either transplant or nontransplant patients: no further trials required

BACKGROUND

To assess whether prostaglandin E1 analogs have a role in either reducing renal allograft rejection or improving renal function among both transplant and nontransplant patients.

METHODS

Studies were identified through Ovid MEDLINE between 1981 and December 1997 using multiple MeSH headings and text words related to renal or liver transplantation, as well as renal insufficiency. These items were crossed with MeSH headings and text words related to prostaglandins and prostaglandin E1. All abstracts were read, in addition to review articles, and their bibliographies were searched for further references. Articles were limited to those published in the English language. Studies were selected based on the following criteria: (1) a randomized control clinical trial; (2) administration of any form of prostaglandin; (3) publication of primary data; and (4) reporting on either renal transplant rejection or renal dysfunction after transplant or, for both transplant and nontransplant studies, objectively comparing a change in renal function from before to after prostaglandin E1 therapy. From the 217 articles that were retrieved, 19 met all inclusion criteria. Data were extracted on study design, nature of the study subjects, and the principal therapeutic intervention. Among the transplant studies, the rate of acute renal graft rejection or renal dysfunction was calculated for each study and then pooled using a random effects model. In addition, the mean change in renal glomerular filtration rate was compared between prostaglandin E1 and controls among both transplant and nontransplant studies and then pooled using an inverse variance-weighted method. Using the Breslow-Day method, statistical heterogeneity was defined at a two-sided P value less than 0.10.

RESULTS

Within the 10 transplant trials, all patients were on cyclosporine; oral or intravenous prostaglandin E1 was generally started within 24 hr of transplantation. Renal transplant rejection or renal dysfunction was not significantly reduced with prostaglandin E1 (odds ratio 0.91, 95% confidence interval [CI] 0.64 to 1.28, two-sided P value=0.58; weighted control event 66.9%, 95% CI 50.5 to 80.0). The glomerular filtration rate was estimated within nine transplant studies, with a minimal positive gain in renal function with prostaglandin E1 (mean difference 2.3 ml/min, 95% CI 1.6 to 3.1). Nine other randomized, double-blinded trials evaluated the effect of prostaglandin E1 on renal function among a variety of nontransplant patients. These patients were generally selected based on their susceptibility to renal injury, with a concomitant exposure to nonsteroidal anti-inflammatory drugs. No significant change in the glomerular filtration rate was observed between prostaglandin E1 and placebo arms (mean difference 0.5 ml/min in favor of placebo, 95% CI -2.8 to 1.8). However, these studies were very heterogeneous.

CONCLUSIONS

Among both transplant and nontransplant populations, prostaglandin E1 does not seem to preserve or improve renal function. Further research is unlikely to demonstrate superiority of prostaglandin E1 in the context of cyclosporine or nonsteroidal anti-inflammatory drug use.