Gastrointestinal mucosal lesions. A drug formulation problem

Digestive System 1

This chapter deals with the digestive system. The major and minor salivary glands and their secretions also represent and integral part of the protective mechanism of the oral cavity, and derangement of saliva production may lead to loss of integrity of the oral mucosa. Drug-induced abnormalities of taste sensation are also well-described phenomena occurring in man although human studies are necessary for the detection of these effects. Inflammation of the oral cavity may involve the buccal mucosa, the gingiva (gingivitis), the tongue (glossitis), and the peridontal tissues (peridontitis). Therapeutic agents can induce inflammatory lesions in the tongue. Moreover, a protective layer of mucus, a visco-elastic material containing high molecular weight glycoproteins produced by the major and minor salivary glands, covers the stratified squamous mucosa of the oral cavity. Salivary secretions also possess digestive enzyme activity although in herbivores and carnivores, it is usually low in contrast to high digestive enzyme activity in omnivorous species.

Oropharyngeal granulomas and tracheal cartilage degeneration in Fischer-344 rats

The development of tracheal cartilage degeneration and inflammation of the seromucinous glands of the oropharynx may be a factor causing early mortalities in long-term studies with Fischer-344 (F-344) rats. The presence of these lesions was investigated in groups of male and female F-344 rats killed at 6, 19, and 32 wk of age. Half of the rats killed at 19 and 32 wk of age were sham treated with water (pH 10) by daily oral gavage for a duration of 13 or 26 wk prior to autopsy in order to detect any influence on the laryngotracheal cavity due to dosing technique. A clear age-associated increase in severity and incidence of chondroid degeneration of the tracheal and laryngeal cartilage was revealed, with an onset as early as 6 wk of age. After 19 wk, a high frequency of oropharyngeal granuloma formation was found. No relationship of the lesions to the gavage technique was apparent. The F-344 rat strain may possess a predisposition for inflammatory and degenerative changes in the oropharyngeal and laryngotracheal cavity, changes that can lead to increased and unexpected mortality rates in nonclinical safety studies (7).

A comparison of severe gastric damage as a result of pirprofen and naproxen treatment in rheumatoid arthritis: a controlled endoscopic study

OBJECTIVE

The aim of this controlled endoscopic study was to compare the therapeutic efficacy and the gastric tolerance of two nonsteroidal anti-inflammatory drugs, pirprofen versus naproxen.

DESIGN

A randomized endoscopic double-blind double-dummy study.

SETTING

The gastrointestinal unit of a teaching hospital.

SUBJECTS

Forty patients suffering from rheumatoid arthritis were enrolled. After an initial upper gastrointestinal endoscopy to rule out the presence of gastric mucosal lesions, the patients were randomly allocated in a double-blind, double-dummy manner, to receive either pirprofen (400 mg t.i.d.) or naproxen (500 mg b.i.d.) for 4 weeks; endoscopic control followed this treatment period, or was anticipated in the event of painful dyspepsia.

INTERVENTIONS

Endoscopy at the beginning of the study and at 4 weeks, or anticipated in the event of painful dyspepsia.

MAIN OUTCOME MEASURES

Primary outcome measure of the study was the possibility that pirprofen was less toxic to the gastric mucosa than naproxen, and at least as effective.

RESULTS

Both drugs proved effective in relieving clinical symptoms, without a statistically significant difference. Gastric mucosa lesions were observed in 90% of pirprofen-treated patients and in 60% of those on naproxen (P = 0.03). The most severe lesions (grades 3 and 4) were found in 65% of subjects treated with pirprofen, as opposed to 15% of those treated with naproxen (P = 0.001).

CONCLUSIONS

This study shows that pirprofen is at least as active as naproxen in relieving rheumatic symptoms, but its administration results in a significantly severe degree of gastric damage.

Clinical pharmacology of predisintegrated ibuprofen 800 mg tablets: an endoscopic and pharmacokinetic study

Thirty-five healthy adults were randomized to receive either: (1) ibuprofen 800 mg tablets; (2) ibuprofen 800 mg aqueous suspension; (3) ibuprofen 800 mg orange juice suspension; or (3) 325 mg aspirin tablets. All treatments were tid for 7 days. Pharmacokinetic sampling was conducted on days 1, 4 and 8. Gastroduodenoscopy was performed on days 1 and 8. Side effects and safety laboratory tests were monitored throughout the study. On day 8 the aspirin group showed significantly more gastric irritation than all of the ibuprofen groups (P less than .005). Both ibuprofen suspension groups showed more gastric irritation than the ibuprofen tablet group (P less than .1). The duodenal scores did not differ among the treatment groups. The aspirin group experienced a higher rate of tinnitus and abdominal pain. The rate and extent of absorption of the ibuprofen suspensions were significantly less than that of the tablets. These data suggest that the taking of ibuprofen as an extemporaneous suspension is therapeutically inferior to ibuprofen tablets and therefore should be discouraged.