Medicamentos disponibles en pediatría para el tratamiento de la enfermedad por reflujo gastroesofágico / Paediatric drugs available for the treatment of the gastroesophageal reflux disease

Se analiza la oferta del mercado farmacéutico español a la hora de cubrir el tratamiento de la Enfermedad por Reflujo Gastroesofágico (ERGE) en la población pediátrica. Para ello se realiza una revisión de las especialidades correspondientes a los grupos A03AF, A02BA y A02BC, a partir del catálogo de especialidades farmacéuticas del Consejo General de Colegios Farmacéuticos, en la que se atendió a: - Dosis indicada en el niño, en caso de ser un fármaco de uso pediátrico.- Formas farmacéuticas en que se presentan estos fármacos. A partir de esta revisión se establecen dos grupos: El 44 por ciento de los fármacos implicados en el tratamiento de la ERGE no se dispone de estudios en la población pediátrica. El 33 por ciento de los AH2 y el 40 por ciento de los IBP son utilizables en niños. Ningún IBP posee presentación correctamente diseñada para la población pediátrica. Se llega a la conclusión, de que el mercado actual no dispone de medicamentos correctamente diseñados para pediatría en las terapias más efectivas en el tratamiento de la ERGE (AU)

Antiulcer drug prescribing in hospital successfully influenced by "immediate concurrent feedback".

OBJECTIVE: To determine whether immediate concurrent feedback (ICF) focused on inpatient omeprazole prescribing achieved more rational and cost-effective antiulcer drug prescribing and usage. METHODS: In a 1400-bed teaching hospital, an audit (by specially trained personnel) was conducted to monitor inpatient prescribing of omeprazole (1) in preference to H2-antagonists and other drugs according to agreed criteria (Helicobacter pylori eradication, severe reflux esophagitis, rapid ulcer healing deemed urgent because of severe symptoms or complications, high-dose steroid therapy of > or =30 mg/day prednisolone) and (2) appropriateness of intravenous dosing (oral route not feasible or contraindicated). After baseline monitoring for 1 month, followed by relevant antiulcer drug therapy education, ICF was instituted for 1 year. This entailed explanatory memoranda requesting a change in prescribing issued to the respective medical teams of patients whose omeprazole prescription did not "conform." The main outcomes of the study were omeprazole prescription numbers per month and the proportion conforming, defined daily doses of antiulcer drugs used and corresponding expenditures, and pertinent antiulcer drug utilization data from 9 other local hospitals. RESULTS: Baseline omeprazole prescribing conformed in 32 of 173 (18%) of the patients compared with 451 of 546 (83%) during institution of ICF (P < 0001; chi2 test). Correspondingly, average overall omeprazole and ranitidine usage (inpatient and outpatient) and expenditure decreased (44% and 45%, respectively); collectively, use of less expensive alternatives increased about 61%. Estimated savings averaged about HK$150,000 ($20,000) per month. No comparable changes in usage were noted in 9 other local hospitals. CONCLUSION: Regarding hospital antiulcer drugs, this ICF strategy was associated with more rational prescribing and usage, and an important saving of resources.

Control of gastric acid with high dose H2-receptor antagonists after omeprazole failure: report of two cases.

Successful omeprazole therapy in patients with symptomatic gastroesophageal reflux (GER) refractory to treatment with H2-receptor antagonists has often been reported. In contrast, successful treatment of GER by H2-receptor antagonists in patients resistant to the acid-suppressing effects of omeprazole is rarely reported. We describe two patients who demonstrated therapeutic responses to high dose H2-receptor antagonists after high dose omeprazole failed to suppress gastric acidity and GER.

The consequences of H2 receptor antagonist--piroxicam coadministration in patients with joint disorders.

A randomised crossover study was performed in subjects with rheumatoid arthritis (or other arthropathies) to investigate if any alteration in the steady pharmacokinetics of the NSAID piroxicam (a drug which is extensively metabolised via cytochrome P450) or its major metabolites occurred as a result of coadministering either cimetidine or nizatidine. Twelve females and 2 males with mean age, weight, and albumin concentrations of 58 years, 61 kg, and 40 g.L-1 respectively, completed the study. Comparisons were made between the following parameters: plasma piroxicam AUCs [AUC0-24(P)], plasma 5-hydroxypiroxicam AUCs [AUC0-24(5-OHP)], the ratio of these i.e. AUC0-24(5-OHP):AUC0-24(p), the % piroxicam daily dose excreted in urine as 5-hydroxypiroxicam (before and after glucuronidase incubation); and the mean of the steady state trough piroxicam, and 5-hydroxypiroxicam concentrations (obtained during each study phase in addition to the wash-out period). A statistically significant difference as a result of initiating either cimetidine or nizatidine was obtained only for the ratio AUC0-23(5-OHP):AUC0-24(P). This was indicative of a weak potential to inhibit piroxicam hydroxylation. No clinically significant alteration in the steady state pharmacokinetics of piroxicam occurred in these subjects as a result of cimetidine or nizatidine coadministration. Consequently it is unlikely that any adverse events would arise from these combinations.

Endocrine effects of a new histamine H2-receptor antagonist, nizatidine (LY139037), in the male rat.

A new orally active histamine H2-receptor antagonist, nizatidine (LY139037), was evaluated in male rats for effects on mechanisms regulating accessory sex organ growth and function. Cimetidine antagonized androgen binding to cytosolic receptors in vitro while nizatidine had no effect. Nizatidine and cimetidine were administered at the ED50, 5 X ED50, or 10 X ED50 doses for inhibition of gastric acid secretion previously determined using in vivo dog and rat models. The relative potencies of both agents to antagonize histamine H2-receptor-mediated gastric acid secretory responses have been confirmed in human clinical trials. Neither nizatidine nor cimetidine antagonized the in vivo uptake or nuclear translocation of radiolabeled androgen into the hypothalamic-preoptic-amygdala, pituitary, or ventral prostate. Nizatidine, given at doses equal to and 10 X the ED50 gastric acid secretion inhibitory values, and cimetidine (10 X ED50 value) had no effect on the response of male accessory sex organs to a submaximally stimulating dose of androgen in castrated rats. High doses of dietary nizatidine (greater than 500 mg/kg-day) administered for 6 months did not alter intact rat male accessory sex organ weights or circulating androgen levels relative to untreated controls. Acute administration of either nizatidine or cimetidine produced transient elevations in plasma prolactin (PRL) levels. Cimetidine was more potent and consistent than nizatidine in producing these increases in circulating PRL. The data described herein support the contention that unlike cimetidine, nizatidine is not a pharmacological antagonist of androgen action and has less of a stimulatory effect upon plasma prolactin. Taken together, these studies indicate that in the male rat, nizatidine exhibits a large therapeutic index between its gastric antisecretory activity and potential endocrinological effects.