Pharmacokinetic interaction between acetaminophen and lansoprazole

Acetaminophen or Nonsteroidal Anti-Inflammatory Drugs in Acute Musculoskeletal Trauma: A Multicenter, Double-Blind, Randomized, Clinical Trial

STUDY OBJECTIVE

We determine whether pain treatment with acetaminophen was not inferior to nonsteroidal anti-inflammatory drugs or the combination of both in minor musculoskeletal trauma.

METHODS

The Paracetamol or NSAIDs in Acute Musculoskeletal Trauma Study was a double-blind, randomized, clinical trial conducted in 2 general practices and 2 emergency departments in the Netherlands. A total of 547 adults, aged 18 years and older, with acute blunt minor musculoskeletal extremity trauma were randomly assigned in a 1:1:1 ratio to acetaminophen 4,000 mg/day, diclofenac 150 mg/day, or acetaminophen 4,000 mg/day+diclofenac 150 mg/day during 3 consecutive days. Patients, health care staff, and outcome assessors were blinded for treatment allocation. Follow-up for each patient was 30 days. Primary outcome measures were between-group differences in mean numeric rating scale (NRS) pain scores in rest and with movement at 90 minutes after initial drug administration compared with baseline pain scores with a predefined noninferiority margin of 0.75 NRS points. Secondary outcomes included NRS pain scores during 3 consecutive days and need for additional analgesia.

RESULTS

One hundred eighty-two patients were treated with acetaminophen, 183 with diclofenac, and 182 with combination treatment. Intention-to-treat analysis revealed mean NRS reduction in rest -1.23 (95% confidence interval [CI] -1.50 to -0.95) and -1.72 (95% CI -2.01 to -1.44) with movement, both for acetaminophen at 90 minutes compared with baseline. Pairwise comparison in rest with diclofenac showed a difference of -0.027 (97.5% CI -0.45 to 0.39) and -0.052 (97.5% CI -0.46 to 0.36) for combination treatment. With movement, these numbers were -0.20 (97.5% CI -0.64 to 0.23) and -0.39 (97.5% CI -0.80 to 0.018), respectively. All differences were well below the predefined noninferiority margin.

CONCLUSION

Pain treatment with acetaminophen was not inferior to that with diclofenac or the combination of acetaminophen and diclofenac in acute minor musculoskeletal extremity trauma, both in rest and with movement.

N-acetyl-4-aminophenol and musculoskeletal adaptations to resistance exercise training

N-acetyl-4-aminophenol (ACET) may impair musculoskeletal adaptations to progressive resistance exercise training (PRT) by inhibiting exercise-induced muscle protein synthesis and bone formation. To test the hypothesis that ACET would diminish training-induced increases in fat-free mass (FFM) and osteogenesis, untrained men (n = 26) aged ≥50 years participated in 16 weeks of high-intensity PRT and bone-loading exercises and were randomly assigned to take ACET (1,000 mg/day) or placebo (PLAC) 2 h before each exercise session. Total body FFM was measured by DXA at baseline and week 16. Serum bone-specific alkaline phosphatase (BAP) and C-terminal crosslinks of type-I collagen (CTX) were measured at baseline and week 16. Vastus lateralis muscle biopsies were performed at baseline and weeks 3 and 16 for prostanoid, anabolic, and catabolic gene expression by RT-PCR. In exercise-compliant men (ACET, n = 10; PLAC, n = 7), the increase in FFM was not different between groups (p = 0.91). The changes in serum BAP and CTX were not different between groups (p > 0.7). There were no significant changes in any of the target genes at week 3. After 16 weeks of PRT, the mRNA expressions of the anabolic marker p70S6K (p = 0.003) and catabolic marker muscle-atrophy F-box (MAFbx) (p = 0.03) were significantly reduced as compared to baseline in ACET. The mRNA expression of the prostanoids were unchanged (all p ≥ 0.40) in both groups. The administration of ACET (1,000 mg) prior to each exercise session did not impair PRT-induced increases in FFM or significantly alter bone formation markers in middle aged and older men.

Effects of Histamine-2 Receptor Antagonists and Proton Pump Inhibitors on the Rate of Gastric Emptying: A Crossover Study Using a Continuous Real-Time C Breath Test (BreathID System)

BACKGROUND/AIMS

The effects of Histamine-2 receptor antagonists and proton pump inhibitors on the gastrointestinal motility have not yet been sufficiently investigated. The aim of this study was to determine the effects of intravenous bolus administration of famotidine and omeprazole on the rate of gastric emptying using the continuous (13)C breath test (BreathID system, Exalenz Bioscience Ltd, Israel).

METHODS

Twelve healthy male volunteers participated in this randomized, 3-way crossover study. After fasting overnight, the subjects were randomly assigned to receive 20 mg of famotidine, 20 mg of omeprazole or 20 mL of saline alone by intravenous bolus injection before a test meal (200 kcal per 200 mL, containing 100 mg of (13)C-acetate). Gastric emptying was monitored for 4 hours after the ingestion of test meal by the (13)C-acetic acid breath test performed using the BreathID system.

RESULTS

No significant differences in the calculated parameters, namely, the T(1/2), T(lag), GEC, β and κ, were observed among the 3 test conditions.

CONCLUSIONS

The study revealed that intravenous administration of gastric acid suppressant drugs had no significant influence on the rate of gastric emptying in comparison with that of saline alone as a placebo. Our results indicating the absence of any effect of either famotidine or omeprazole on accelerating the rate of gastric emptying suggest that both medications can be administered safely to patients suffering from hemorrhagic peptic ulcers who need to be kept nil by mouth from the viewpoint of possible acceleration of gastrointestinal motility in the clinical setting.

Effects of proton pump inhibitors on gastric emptying: a systematic review

The proton pump inhibitor (PPI) is widely used for the treatment of gastroesophageal reflux disease, peptic ulcer diseases, and functional dyspepsia. The pathogenesis of these acid-related and/or functional upper gastrointestinal disorders is potentially associated with abnormal gastric emptying. To date, variable effects of PPIs on gastric emptying have been reported. Therefore, it is relevant to gather and analyze published information on this topic. A systematic literature search has been performed, showing that the delaying effect of PPIs on gastric emptying of solid meals is consistent, whereas the effect of PPIs on the emptying of liquids is inconsistent. The underlying mechanisms whereby PPIs may affect gastric emptying have been discussed, most of which still remain hypothetic. Gastric emptying of solids involves a process of peptic hydrolysis. PPIs impair the hydrolytic digestion by inhibiting acid-dependent peptic activity, thereby delaying the solid emptying. Gastric emptying of liquids largely depends on volume and energy density of intragastric contents. PPIs variably modify the volume and the energy density by reducing gastric fluid secretion, thereby modifying the liquid emptying in an unpredictable manner. Hypergastrinemia has been considered to delay gastric emptying, but it seems of minor importance in the regulation of gastric emptying during PPI use. The delayed emptying of solids due to PPI therapy may have clinical implications in the management of gastroesophageal reflux disease, functional dyspepsia, as well as diabetes.

Acetaminophen safety and hepatotoxicity--where do we go from here?

Acetaminophen has been widely used for > 50 years in the treatment of pain and fever and provides for the safe and effective relief of these symptoms. In a small minority of patients, however, acetaminophen is responsible for life-threatening liver injury and accounts for up to 50% of all adult cases of acute liver failure in the US. Although approximately two-thirds of adult overdoses are associated with suicide attempts, many are inadvertent, often due to the use of multiple acetaminophen formulations over many days. Additionally, some individuals appear to experience acetaminophen toxicity at 'therapeutic' doses of < 4 g/day, for reasons unknown. In pediatric populations, the overwhelming majority of acetaminophen overdoses are due to unintentional overdoses, except for the predominance of suicidal ingestions in the teenage population. This article seeks to review the mechanism and metabolism of acetaminophen and the features of toxicity in adults, pediatric and special populations. Additionally, expert opinion is presented herein to aid in reducing the frequency and severity of liver injury from acetaminophen.

Lansoprazole: an update of its place in the management of acid-related disorders

Lansoprazole is an inhibitor of gastric acid secretion and also exhibits antibacterial activity against Helicobacter pylori in vitro. Current therapy for peptic ulcer disease focuses on the eradication of H. pylori infection with maintenance therapy indicated in those patients who are not cured of H. pylori and those with ulcers resistant to healing. Lansoprazole 30 mg combined with amoxicillin 1g, clarithromycin 250 or 500mg, or metronidazole 400 mg twice daily was associated with eradication rates ranging from 71 to 94%, and ulcer healing rates were generally >80% in well designed studies. In addition, it was as effective as omeprazole- or rabeprazole-based regimens which included these antimicrobial agents. Maintenance therapy with lansoprazole 30 mg/day was significantly more effective than either placebo or ranitidine in preventing ulcer relapse. Importantly, preliminary data suggest that lansoprazole-based eradication therapy is effective in children and the elderly. In the short-term treatment of patients with gastro-oesophageal reflux disease (GORD), lansoprazole 15, 30 or 60 mg/day was significantly more effective than placebo, ranitidine 300 mg/day or cisapride 40 mg/day and similar in efficacy to pantoprazole 40 mg/day in terms of healing of oesophagitis. Lansoprazole 30 mg/day, omeprazole 20 mg/day and pantoprazole 40 mg/day all provided similar symptom relief in these patients. In patients with healed oesophagitis. 12-month maintenance therapy with lansoprazole 15 or 30 mg/day prevented recurrence and was similar to or more effective than omeprazole 10 or 20 mg/day. Available data in patients with NSAID-related disorders or acid-related dyspepsia suggest that lansoprazole is effective in these patients in terms of the prevention of NSAID-related gastrointestinal complications, ulcer healing and symptom relief. Meta-analytic data and postmarketing surveillance in >30,000 patients indicate that lansoprazole is well tolerated both as monotherapy and in combination with antimicrobial agents. After lansoprazole monotherapy commonly reported adverse events included dose-dependent diarrhoea, nausea/vomiting, headache and abdominal pain. After short-term treatment in patients with peptic ulcer, GORD, dyspepsia and gastritis the incidence of adverse events associated with lansoprazole was generally < or = 5%. Similar adverse events were seen in long-term trials, although the incidence was generally higher (< or = 10%). When lansoprazole was administered in combination with amoxicillin, clarithromycin or metronidazole adverse events included diarrhoea, headache and taste disturbance. In conclusion, lansoprazole-based triple therapy is an effective treatment option for the eradication of H. pylori infection in patients with peptic ulcer disease. Preliminary data suggest it may have an important role in the management of this infection in children and the elderly. In the short-term management of GORD, lansoprazole monotherapy offers a more effective alternative to histamine H2-receptor antagonists and initial data indicate that it is an effective short-term treatment option in children and adolescents. In adults lansoprazole maintenance therapy is also an established treatment option for the long-term management of this chronic disease. Lansoprazole has a role in the treatment and prevention of NSAID-related ulcers and the treatment of acid-related dyspepsia; however, further studies are needed to confirm its place in these indications. Lansoprazole has emerged as a useful and well tolerated treatment option in the management of acid-related disorders.