Bioequivalence and Safety of Twice-Daily Sustained-Release Paracetamol (Acetaminophen) Compared With 3- and 4-Times-Daily Paracetamol: A Repeat-Dose, Crossover Pharmacokinetic Study in Healthy Volunteers

Endoscopic comparison of gastroduodenal injury with over-the-counter doses of new fast-dissolving ibuprofen and paracetamol formulations: a randomized, placebo-controlled, 4-way crossover clinical trial

Background

While gastrointestinal (GI) effects of standard ibuprofen and N-acetyl-p-aminophenol (APAP) have been reported, upper GI injury following treatment with fast-dissolving (FD) formulations of these analgesics has not been investigated. We evaluated upper GI effects of over-the-counter doses of 2 FD ibuprofen products and 1 FD-APAP product.

Methods

In a randomized, placebo-controlled, endoscopist-blinded, 4-way crossover study, 28 healthy subjects received FD ibuprofen 2×200 mg liquid capsules 3 times daily (TID), ibuprofen 2×200 mg tablets TID, FD-APAP 2×500 mg tablets 4 times daily (QID), and placebo 2×500 mg tablets QID for 7 days. The primary end point was gastric mucosal damage assessed by endoscopy using the Lanza scale: 0=normal stomach or proximal duodenum, 1=mucosal hemorrhages only, 2=1 or 2 erosions, 3=numerous (3-10) erosions, and 4=large number of erosions (>10) or ulcer. Secondary end points included duodenal mucosal damage (Lanza scale); gastroduodenal mucosal injury, classified as present (gastric and/or duodenal endoscopy score ≥2) or absent (gastric and/or duodenal endoscopy score <2); and number of hemorrhages, erosions, and ulcers counted separately in the stomach and duodenum.

Results

Significantly greater gastric mucosal injury was observed after treatment with both ibuprofen products vs FD-APAP (p<0.0001 and p=0.0095, respectively). FD-APAP showed no difference from placebo (p=0.4794). The odds of having an incidence of gastroduodenal mucosal injury were over 6 times greater from FD ibuprofen liquid capsule treatment (odds ratio [OR]=6.19, 95% confidence interval [CI]: 1.60, 23.97) and over 3 times greater from ibuprofen tablet treatment (OR=3.19, 95% CI: 0.8, 12.74) vs FD-APAP.

Conclusion

Treatment with 2 ibuprofen products was associated with significant gastric mucosal injury. Of the 4 treatments studied, FD ibuprofen liquid capsules had the highest risk of incidence of gastroduodenal mucosal injury. Treatment with FD-APAP did not induce any clinically or statistically significant gastroduodenal mucosal injury.

Efficacy and safety of twice daily sustained-release paracetamol formulation for osteoarthritis pain of the knee or hip: a randomized, double-blind, placebo-controlled, twelve-week study

OBJECTIVE

Evaluate efficacy and safety of an investigational, twice daily sustained-release (SR) paracetamol formulation in subjects with knee or hip osteoarthritis (OA).

METHODS

In this multicenter, double-blind, parallel study (NCT02311881), subjects with hip or knee OA were randomly assigned to SR paracetamol 2 × 1000 mg BID, extended-release (ER) paracetamol 2 × 665 mg TID or placebo for 12 weeks. Primary endpoint was mean change from baseline through 12 weeks in WOMAC Osteoarthritis Index pain. Secondary efficacy endpoints included other WOMAC categories, Global Patient Assessment of Osteoarthritis (GPAOA), Patient Global Assessment of Response to Therapy (PGART) and responder rate.

RESULTS

A total of 676 subjects were included in the analysis population (mITT). Mean change from baseline in WOMAC pain subscale was not significantly greater with SR paracetamol BID versus placebo (LS mean [SE]: -28.25 [1.697] vs. -25.74 [1.713]; p = .163). Reduction in WOMAC physical function and stiffness subscales with SR paracetamol BID was not significantly greater than with placebo (p = .089 and .054, respectively). Significant improvement over placebo was observed for GPAOA (p = .043), PGART (p = .012), and proportion of high-improvement responders (p = .015). Safety and tolerability were consistent with the known profile of paracetamol.

CONCLUSIONS

Improvement in WOMAC pain, physical function and stiffness subscales from treatment with SR paracetamol BID versus placebo in subjects with knee or hip OA was not significant. SR paracetamol BID demonstrated significant improvements in GPAOA, PGART, and high-responder rate. High placebo response may have contributed to lack of statistical separation on some outcomes. All interventions were generally well tolerated.