Drugs
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Review Comparative Study
Milrinone. A preliminary review of its pharmacological properties and therapeutic use.
Milrinone is a bipyridine derivative of amrinone, with approximately 10 to 75 times greater positive inotropic potency, and separate direct vasodilatory properties. As with amrinone, the relative importance of these properties to treatment of congestive heart failure still remain controversial. The mode of action of milrinone appears to be due in part to selective inhibition of a specific cardiac phosphodiesterase with a subsequent increase in intracellular cyclic adenosine monophosphate and alteration in intracellular and extracellular calcium transport. ⋯ One small study suggests that short term effects of intravenous milrinone may be superior to those of oral captopril, and it appears that the addition of captopril to milrinone therapy may produce a synergistic haemodynamic effect. Preliminary long term studies suggest that tolerance to the haemodynamic effects of milrinone does not occur, and that the drug is well tolerated and without the thrombocytopenic effects, fever and gastrointestinal complications observed with amrinone. However, it has not been demonstrated that milrinone improves the prognosis of the disease or the overall mortality and its propensity to produce arrhythmias has not been fully agreed upon.(ABSTRACT TRUNCATED AT 400 WORDS)
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Small spinal (intrathecal or extrathecal) doses of opioids induce a long-lasting and regional analgesic effect in various experimental animal models. Nowadays extrathecal morphine administration is considered an established method of controlling postoperative and cancer-induced pain conditions. The potency of morphine applied by the spinal route is higher than when the drug is applied by the intravenous (IV) route. ⋯ There are risks in replacing opioid administration by the oral or IV route with spinal opioids. Morphine should only be used in selected cases until the advantage of spinal opioid analgesia to control postoperative and cancer pain has been clearly defined in well-designed clinical studies. Spinal morphine dosages must be individualised according to the intensity of the nociceptive stimuli and should take into account intra-individual variability in drug responses due to pharmacokinetic and pharmacodynamic factors.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effects of roxatidine acetate on 24-hour gastric acidity. Early evening versus bedtime administration in healthy subjects.
The gastric antisecretory activity of roxatidine acetate was studied on 24-hour intragastric pH in 12 healthy male volunteers. The study was randomised, double-blind and double-dummy where either roxatidine acetate 150 mg as a slow release granulated formulation or placebo were administered at 7.30 pm or 10 pm. ⋯ There was no significant difference between the median intragastric pH values for early evening and bedtime administration of roxatidine acetate. The present data confirm that roxatidine acetate 150 mg inhibits gastric acid secretion but while a single evening dose is effective in controlling intragastric pH the results suggest there is no clear advantage in an early evening dose compared with a bedtime dose.
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Randomized Controlled Trial Comparative Study Clinical Trial
The effects of roxatidine acetate on 24-hour intragastric acidity. Investigations in healthy volunteers and comparison with ranitidine and placebo.
In a series of double-blind randomised studies in normal volunteers with continuous intragastric pH monitoring, the effects of different dosage regimens of roxatidine acetate, a new H2-receptor antagonist, were compared with placebo and ranitidine. Roxatidine acetate 75 mg twice daily decreased median 24-hour gastric acidity from pH 1.6 to 3.2 and median nocturnal acidity from 1.5 to 3.0. ⋯ However, when drugs were taken after the evening meal (post cenam nocte; PCN) roxatidine acetate 150 mg was less potent than ranitidine 300 mg, with median night-time pH rising from 1.3 to 3.2 and 4.0, respectively, in 28 volunteers. Roxatidine acetate 300 mg PCN produced the greatest rise of pH, to 4.9, suggesting that the true potency ratio of the 2 drugs is between 1 and 2.
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Randomized Controlled Trial Clinical Trial
The use of roxatidine acetate in fasting patients prior to induction of anaesthesia as prophylaxis against the acid aspiration syndrome.
Aspiration pneumonitis is one of the major causes of anaesthesia related deaths. H2-receptor antagonists are effective drugs for the prevention of the acid aspiration syndrome (Mendelson's syndrome). The new long-acting H2-receptor antagonist roxatidine acetate may be the first H2-receptor antagonist which could effectively reduce acid secretion following a single bedtime premedication on the evening before an operation. ⋯ The mean gastric volume in the placebo group was 23.3 +/- 27.1 ml, compared to 14.5 +/- 9.4 ml for roxatidine acetate. The 5 highest gastric volumes were observed in the placebo group (max 146 ml). A single bedtime oral premedication with roxatidine acetate 150 mg ensures a gastric pH above 2.5 until 11 am the following day.