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Biomedical subjects

C C Snell

Publications and source records attributed to C C Snell.

4 recordsLinked to original sources
PubMed1998

The effects of low doses of ranitidine on intragastric acidity in healthy men.

BACKGROUND: H2-receptor antagonists are becoming widely available as over-the-counter medications for the treatment of heartburn and excess gastric acidity. AIM: To determine the effects of single low doses of ranitidine on intragastric acidity. METHODS: Intragastric pH was measured for 9 h after lunch in five studies involving 24 healthy male volunteers. Antacid was given to all subjects on day 1. They then received single oral doses of a study drug 45 min after lunch on four separate occasions: placebo and either ranitidine 25 mg, 75 mg or 125 mg were given double-blind according to a predetermined randomization schedule. RESULTS: During both of the post-dosing time periods (0-5 h and 5-9 h) there were significant decreases in integrated intragastric acidity for each ranitidine dose compared with placebo (P < 0.0001). There was a significant linear relationship between dose and integrated intragastric acidity with a greater decrease in acidity with increasing ranitidine doses (P < 0.0001). Compared with placebo, time with pH > 3 was significantly greater for ranitidine 75 mg and 125 mg (P < 0.001), but not ranitidine 25 mg. Results with the antacid were similar to placebo. CONCLUSIONS: Using low doses of ranitidine (25, 75 or 125 mg) there was a dose-related decrease in intragastric acidity for 9 h after dosing. A single dose of antacid did not decrease intragastric acidity significantly.

Adult↗
PubMed1997

Inhibition of intragastric acidity in healthy subjects dosed with ranitidine 75 mg: a comparative study with cimetidine and placebo.

BACKGROUND: Despite the widespread use of over-the-counter H2-receptor antagonists little is known about their duration of action on human gastric acid secretion. There are studies reporting inhibitory effects for up to 9 h post-dose but few data beyond this period. METHODS: Profiles of 20-h intragastric acidity were measured simultaneously in 24 healthy subjects who were dosed (at 12.30 h) with either ranitidine 75 mg, cimetidine 200 mg or placebo in a three-way crossover study, according to a standard protocol. Five-millilitre aliquots of gastric juice were aspirated half-hourly during the day (0-10 h post-dose) and hourly overnight (10-20 h post-dose). pH was measured to three decimal places with a glass electrode. Weighted intragastric acidity (AUC/time) was calculated for both day- and night-times using 2.5-h intervals during the day and 5-h intervals at night. Statistical analysis was by ANOVA. RESULTS: The results are expressed as mean weighted intragastric acidity (mmol/L). (i) Daytime (0-10 h post-dose): when dosed with placebo the weighted intragastric acidity was 31.03, decreasing to 10.37 (P < 0.001 vs. placebo) and 16.23 (P < 0.001 vs. placebo) when treated with ranitidine and cimetidine, respectively. Ranitidine inhibited weighted intragastric acidity to a greater degree than cimetidine (P < 0.001) during this period. (ii) Night-time (10-20 h post-dose): when dosed with placebo the weighted intragastric acidity was 21.36 decreasing to 16.65 (P < 0.001 vs. placebo) when dosed with ranitidine and remaining unchanged at 20.03 (P = 0.886 vs. placebo) when dosed with cimetidine. Ranitidine inhibited weighted intragastric acidity to a greater degree than cimetidine (P = 0.010) during this period. A sub-analysis of the two 5-h intervals showed that compared to placebo, ranitidine inhibited weighted intragastric acidity significantly in the 10-15 h period. However, its effect in the 15-20 h period did not differ from placebo. CONCLUSIONS: In healthy subjects, the inhibitory effect of ranitidine 75 mg on intragastric acidity can be detected 10-15 h after an oral dose. By contrast, the inhibitory effect of cimetidine 200 mg seems to be restricted to the first 10 h.

Adult↗
PubMed1997

Patient controlled analgesia and intramuscular injections: a comparisons of patient pain experiences and postoperative outcomes.

Despite relatively widespread use of various forms of patient controlled analgesia (PCA), there remain conflicting results in the literature as to the efficacy of PCA. This study was conducted to assess the efficacy and postoperative outcomes of intravenous PCA compared to intramuscular (IM) injections in 73 patients who received major abdominal surgery. These patients were randomly selected and randomly assigned preoperatively to receiving IM or PCA modes of analgesia postoperatively. The following factors were compared: amount of pain; amount of analgesia use; degree of patient satisfaction with pain control both while on parenteral analgesia and after switching to oral; length of time to first ambulation; and length of stay in hospital. Results of the study did not demonstrate a statistically significant difference in any of these, using a P-value of 0.01. The PCA patients took an average of 4.5 hours longer than the IM patients to ambulate postoperatively and the IM patients received at least three times as much antiemetic (P = 0.001). Locus of control was not found to be a major factor in satisfaction or pain levels. Subsequent meta-analyses have also failed to yield significant differences between IM and PCA groups except in patient satisfaction. It is recommended that expansion of PCA programmes with abdominal surgery patients be considered only in cases where there is fiscal advantage or where patient satisfaction can be a driving force.

Adolescent↗