The effects of high-dose ibuprofen and pancreatic enzymes on the intestine of the rat

Pharmacokinetics of Ibuprofen in children with cystic fibrosis

An exaggerated inflammatory response is responsible for the decline of lung function in patients with cystic fibrosis (CF). Ibuprofen is a potent anti-inflammatory agent that demonstrates inhibition of neutrophil activity in vitro at concentrations between 50 and 100 mg/L, whereas lower concentrations result in an increase in inflammatory mediators. Significant decline in the rate of deterioration of pulmonary function and increased nutritional status were observed in children with CF who were administered long-term high-dosage ibuprofen therapy. As with many other drugs, CF patients appear to exhibit altered pharmacokinetics of ibuprofen (reduced bioavailability, increased volume of distribution, and more rapid clearance) when compared with healthy controls. However, the absence of studies with intravenous ibuprofen as well as protein binding measurements in patients with CF currently limits the ability to compare the pharmacokinetics with those in other populations. Current studies indicate that there is high interpatient variability in ibuprofen pharmacokinetics among CF patients. Some of this variability can be explained by differences in ibuprofen formulation administered. Therapeutic drug monitoring of high-dosage ibuprofen therapy is recommended because of the biphasic response to inflammatory mediators demonstrated in vitro as well as the high interpatient variability in pharmacokinetics. Due to the differences in absorption characteristics between ibuprofen formulations, the timing of obtaining blood samples for pharmacokinetic analysis is critical. Maximum a posteriori Bayesian analysis has been shown to provide more accurate and precise estimates of the pharmacokinetic parameters of ibuprofen in children with CF, and may also be a useful tool to further investigate the relationship between measures of drug exposure and efficacy/toxicity outcomes.

Ursodeoxycholic acid ameliorates ibuprofen-induced enteropathy in the rat

BACKGROUND

The objective of the study was to determine whether ursodeoxycholic acid (Ursodiol) is protective against ibuprofen (IBU)-induced enteropathy.

METHODS

Using the chronically catheterized rat model, IBU (60 mg/kg body weight per day) was infused via the gastric catheter twice daily. Pancreatic enzyme (PE; 10,000 U lipase/kg body weight per day) and Ursodiol (10 mg/kg body weight per day) in two doses were infused via the duodenal catheter. Rats were assigned to one of six treatment groups and were administered treatment for 20 days: control, IBU, PE, IBU + PE, IBU + Ursodiol, and IBU + PE + Ursodiol. The entire jejunum, ileum, cecum, and colon were available for histologic analysis using previously described techniques.

RESULTS

Addition of Ursodiol to high-dose IBU and normal doses of PE showed a significant reduction in the percentage of rats with ulcers (P < 0.05), total number of serositis events (P < 0.01), total number of severe ulcers (P < 0.001), and an absence of ulcers in the large intestine.

CONCLUSIONS

Ursodiol, the drug of choice for the treatment of cystic fibrosis liver disease, may offer a safe method of using high-dose IBU in these patients by ameliorating the enteropathy.