Background: Treatment and prevention of non‐steroidal anti‐inflammatory drug‐induced gastropathy involve the concurrent use of antisecretory drugs. Recently, we have shown that the ability of these drugs to increase the intragastric pH to values pKa of NSAIDs compromises their therapeutic activity. In the present study, we evaluated the potential of omeprazole to interfere with the bioavailability of aspirin administered to rats either alone or complexed with the zwitterionic phospholipid, dipalmitoylphosphatidylcholine (DPPC). Methods: Aspirin or aspirin/DPPC was administered intragastrically to rats pre‐dosed with either saline or omeprazole. Concentrations of aspirin and salicylic acid in the blood and the gastric mucosa were assessed by HPLC and the 6‐keto‐PGF1α gastric mucosal concentration by radioimmunoassay. Results: Gastric absorption of aspirin and its relative bioavailability were reduced by an antisecretory dose of omeprazole; its inhibitory effect on gastric prostaglandin synthesis was consequently attenuated. However, these effects could be partly overcome if aspirin was administered as a complex with DPPC. Conclusions: These observations suggest that: (i) DPPC increases the lipid solubility and gastric permeability of NSAIDs; and (ii) neutralization of the gastric pH results in a shift of aspirin absorption toward the intestine where it could be degraded to salicylic acid.

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The hypoglycaemic activities of Opuntia ficus-indica, 0. lindheimeri and 0. robusta were investigated in streptozotocin-induced diabetic rats using enteral (oral) and parenteral (intraperitoneal and intravenous) routes of administration. When the aqueous extracts of the three Opunfriz species were administred intraveneously, they produced a hypoglycaemic effect. However, when the extracts were administered orally, only 0. lindheimeri produced a hypoglycaemic effect. A dilute aqueous (ammonium sulphate) solution of 0. lindheimeri dialysate also produced a hypoglycaemic effect when administered intravenously. Intraperitoneal administations of all Opuntia species extracts including 0. lindheimeri dialysate failed to produce hypoglycaemic effects. It appears that the concentration andor potency of the active hypoglycaemic principle in Opuntiu cacti is species-specific.

Previous studies have indicated that sodium diethyldithiocarbamate (DDTC) can reduce cisplatin's (CP) toxic effects without altering the antitumor activity. DDTC has also been shown to have immunostimulative properties. Sixty patients with objectively measurable recurrent and/or metastatic squamous cell carcinoma (SCC) of the head and neck were randomized to receive either (A) CP at 120 mg/m2 over one hour on day 1, plus fluorouracil (5-FU) at 1,000 mg/m2 over 24 hours as a continuous infusion on days 1 through 5, or (B) CP/5-FU as in A, plus DDTC at 600 mg/m2 over 30 minutes administered intravenously (IV) exactly 30 minutes after CP infusion. Group B also received DDTC at 200 mg/m2 administered IV over 30 minutes on days 8 and 15. Each cycle was repeated at 3-week intervals. Objective responses were achieved in 41% of the CP/5-FU group and in 29% of the CP/5-FU with DDTC group (P = .26). Median survival was 9 months in group A and 10 months in group B. CP-related toxicity between the groups was equivalent with respect to nausea and vomiting, renal impairment, neurotoxicity, ototoxicity, and hematologic toxicity. The pharmacokinetics of reactive platinum species in plasma ultrafiltrate and urine samples obtained from both groups were comparable. The immune status of 48 patients was evaluated before and after completion of therapy. There were no significant differences in mean pretreatment and posttreatment values within or between groups A or B, except for absolute pretreatment OKT4 values (P = .02). We conclude that (1) the present dose and infusion schedule of DDTC did not significantly reduce CP-mediated toxic effects, (2) DDTC did not alter the disposition of ultrafilterable platinum species, (3) DDTC did not affect immune responses, and (4) the addition of DDTC improved neither the clinical response nor the survival of patients with recurrent SCC of the head and neck.

The hypoglycaemic activities of Opuntia ficus‐indica, O. lindheimeri and O. robusta were investigated in streptozotocin‐induced diabetic rats using enteral (oral) and parenteral (intraperitoneal and intravenous) routes of administration. When the aqueous extracts of the three Opuntia species were administred intraveneously, they produced a hypoglycaemic effect. However, when the extracts were administered orally, only O. lindheimeri produced a hypoglycaemic effect. A dilute aqueous (ammonium sulphate) solution of O. lindheimeri dialysate also produced a hypoglycaemic effect when administered intravenously. Intraperitoneal administations of all Opuntia species extracts including O. lindheimeri dialysate failed to produce hypoglycaemic effects. It appears that the concentration and/or potency of the active hypoglycaemic principle in Opuntia cacti is species‐specific.