A. Bozzani

Effect of loperamide and naloxone on mouth-to-caecum transit time evaluated by lactulose hydrogen breath test.

The effect of loperamide and naloxone on mouth-to-caecum transit time was evaluated by the lactulose hydrogen breath test in four men and four women. Each subject underwent tests during the administration of placebo, loperamide (12-16 mg po), naloxone (40 micrograms/kg/h by a three-hour intravenous infusion), and loperamide plus naloxone, carried out at intervals of one or two weeks. The transit time was significantly longer after loperamide, and this effect was antagonised by the concomitant administration of naloxone whereas naloxone administered alone had no effect on mean transit time. No clinically important side effects were reported.

Oral naloxone antagonizes loperamide-induced delay of orocecal transit

Orocecal transit time was determined by the lactulose hydrogen breath test in nine healthy volunteers after administration of placebo, loperamide (16 mgper os), and loperamide (16 mgper os) followed by oral naloxone at doses of 16 and 32 mg. The four tests were performed in double-blind conditions and in random sequences. Transit time (mean,sd) after loperamide (128.8 min, 32.9) was significantly increased (P<0.05) compared with placebo (85.5 min, 35.7), loperamide followed by naloxone 16 mg (88.8 min, 46.2), and loperamide followed by naloxone 32 mg (84.4 min, 40.6). These results show that the peripheral opioid agonist loperamide delays orocecal transit in healthy subjects and that naloxoneper os at adequate doses antagonizes this effect.

Orocecal transit delay in obese patients

Orocecal transit time was assessed with lactulose hydrogen breath test in 12 obese patients during intravenous infusion of placebo or naloxone 40 μg/kg/hr given in randomized order and in double-blind conditions. Transit time was also evaluated in 22 healthy controls. Orocecal transit was significantly (P<0.01) longer in the obese patients during placebo treatment (median 130, range 100–200 min) than in the healthy controls (median 75, range 40–170 min). Compared with placebo, transit time in the obese subjects was delayed (P<0.05) during naloxone treatment (median 150, range 100–230 min).

Lactose malabsorption and intolerance in Italians: clinical implications

Lactose malabsorption was assessed by the hydrogen breath test in 40 Italian patients with irritable bowel syndrome and 42 controls without abdominal disturbances. Sixty-five percent of patients were “low milk consumers” (0–250 ml milk per day) compared with 38% of controls (P<0.02). Lactose loads of 25 and 50 g caused malabsorption in 82.5 and 87.5% patients and in 55 and 62% controls, respectively (patients vs controlsP<0.02). Malabsorption was more frequent in the “low milk consumers” group (P<0.05). During a four-month lactose-free diet as the only treatment 7.5% of patients became symptomfree (and remained so for a further eight-month diet), 52.5% improved, and 40% showed no change.

Repeatability of lactulose hydrogen breath test in subjects with normal or prolonged orocecal transit.

The within-subject repeatability of orocecal transit assessed with lactulose hydrogen breath test was evaluated in 15 healthy volunteers and 16 constipated or obese patients. The test was repeated twice in each subject. Mean (sd) transit time was 105 (63) and 103 (60) min in the first and second series of tests, respectively, showing that the first measurement did not affect the second. The within-subject repeatability of the test was related to the length of transit, the scatter of the differences between the first and second test being greater with the increase of the mean gastrointestinal transit time. The 95% coefficient of repeatability was 84 min for all measurements and 30 and 118 min, respectively, for transit times under and over 100 min. The lowest reproducibility of the test was found in constipated patients with prolonged orocecal transit.

Erythrocytapheresis in idiopathic haemochromatosis.

Erythromycin must join the long list of drugs implicated in interstitial nephritis. So far as we know this is the first case of erythromycin induced renal failure proved by renal biopsy. The insidious onset may permit the renal lesion to escape early detection with resultant permanent damage, as in our case. We suggest that renal function should be monitored when erythromycin or other drugs which may induce interstitial nephritis are administered in prolonged or repeated courses.

Spontaneous perforation of an oesophageal diverticulum in achalasia

Spontaneous perforation of the oesophagus is a rare occurrence that is usually due to vomiting and is seldom associated with an oesophageal lesion. We report a case of the spontaneous perforation of a large oesophageal diverticulum not preceded by any precipitating event in a 75-year-old male who was not known to have achalasia. The diverticulum was repaired by emergency surgery. Achalasia was later diagnosed and successfully treated with botulin toxin injection. Surgery decision-making and the treatment of achalasia are discussed.

Intragastric and intraoesophagel pH monitoring in duodenal ulcer patients: effect of the new histamine H2-receptor antagonist ramixotidine

SummaryThe effect of the new histamine H2-receptor antagonist ramixotidine 750 mg p.o., administered at 22.00 h, on intragastric and intraoesophageal pH monitored from 22.00 h to 08.00 h, was studied in a double-blind cross-over trial in 11 duodenal ulcer patients. Placebo and ramixotidine were given to each patient on 2 consecutive days in a randomized sequence. Three patients were excluded from the intragastric pH analysis as the records on the second study day were technically inadequate.No significant carry-over or sequence effect was noted. Intragastric hydrogen ion activity was significantly lower (p=0.01) after ramixotidine than after placebo: median (range) 24 (9–100) vs 97 (27–188) mmol/l. The percentage of time with intraoesophageal pH <4 was less than 5% in all but three recordings, with a maximum value of 12%, and it was not significantly different after the two treatments.