A comparative study for efficacy and safety of low doses of clonidine for hemodynamic stability in patients undergoing laparoscopic cholecystectomy

Background: This randomized prospective double-blind study was designed to evaluate the efficacy and side effects of low doses clonidine for perioperative haemodynamic stability and postoperative recovery.Methods: Patient’s with ASA grade I–II undergoing laparoscopic cholecystectomy were randomized into three groups of 30 patients each. All patients received either normal saline 10 ml (Group I) or 0.8 µg/kg (Group II) or 1 µg/kg (Group III) over duration of 180 seconds, 10 min prior to laryngoscopy and intubation. Anaesthesia was induced with 1% propofol (2 mg/kg) and maintained with nitrous oxide 60% in oxygen and isoflurane. The parameters assessed at various time intervals were heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure and sedation score.Results: Both doses of clonidine proved to be effective in perioperative haemodynamic stability. Clonidine 0.8 mcg/kg was as effectve and safer to Clonidine 1 mcg/kg for attenuatíon of the hemodynamíc responses to laparoscopy. There were no significant differences in the parameters of recovery between groups.Conclusions: Significant hemodynamic derangements can occur during laproscopic cholecystectomy at intubation, pneumoperitoneum and extubation. These were effectively attenuated by premedication with 0.8 mcg/kg and 1 mcg/kg of intravenous clonidine. Dose of 1 mcg/kg though found to be effective but produced adverse effects in form of hypotension and bradycardia.

Substance abuse amongst the medical graduate students in a developing country.

Background & objectives: Substance abuse is found worldwide including among students. We carried out this study to estimate the prevalence of substance abuse among medical student studying in a medical college in north India. Methods: Using a validated questionnaire a cross-sectional survey was conducted among 230 undergraduate and postgraduate medical students in a private medical college. Results: The prevalence of substance abuse was 20.43 per cent (47/230) among medical students. An increase in substance abuse was observed in the latter years of medical education. A total of 43 of 47 (91.7%) students using these substances were aware of the ill effects. The most common reasons for substance use were relief from psychological stress (34/47, 72.4%) and occasional celebration (34/47, 72.4%). Of the 47 substance users, 28 (59.6%) made past attempts to quit the substance abuse. Interpretation & conclusions: Nearly one-fifth of medical students abuse at least one substance despite knowing the ill effects with the main predisposing factor being the psychological stress.

Effects of ranitidine alone and in combination with chlorpheniramine on histamine-induced wheal and flare and psychomotor performance.

Some reports suggest that addition of an H2 antagonist increases the efficacy of H1 antagonist but the influence on the side effect profile of antihistamines are largely unknown. The effects of ranitidine, chlorpheniramine, their combination and placebo on histamine induced wheal and flare, psychomotor performance and subjective symptoms were studied in 6 healthy male volunteers in a double blind randomized and cross-over (Latin square) study. Ranitidine significantly reduced the histamine induced wheal at 4 hrs (P < 0.05). Chlorpheniramine and the combination significantly reduced both histamine induced wheal and flare at 2 hrs and at 4 hrs (P < 0.05). Addition of ranitidine reduced the feeling of sleepiness produced by chlorpheniramine, though other subjective symptoms were not affected. None of the treatment schedules produced any consistent change in the psychomotor performance of the volunteers.

Background noise in healthy volunteers--a consideration in adverse drug reaction studies.

In adverse drug reaction studies proper control over 'Back ground noise' is to be maintained to avoid erroneous conclusions to be drawn for adverse drug effects. Healthy volunteers, not taking any medication, were surveyed by a questionnaire to obtain data on the occurrence of any symptoms, often ascribed to side effects of drugs. Only 62 subjects out of a total of 236 (26.27%) stated experiencing none of these symptoms during the previous 3 days. The remaining subjects reported some symptoms, with an median number of symptoms experienced per person being 2; the most common being fatigue; headache, inability to concentrate and excessive sleepiness.

Effect of fatty diet on pharmacokinetics and pharmacodynamics of a liquid theophylline preparation in volunteers.

The effect of a standard breakfast and a fatty breakfast on the pharmacokinetics and pharmacodynamics of a theophylline liquid preparation (160 mg-single dose) was examined in 6 healthy, non-smoking male volunteers. The plasma theophylline concentrations after both standard and fatty diet were found to be comparable at each point of time and pharmacokinetic parameters like Cmax, Tmax, T1/2a, T1/2 beta and AUC0-alpha, were also comparable. However, the time taken to attain the therapeutic plasma concentration was earlier and sustained along with the standard breakfast in comparison to that with fatty breakfast. Peak change in PEFR and pulse rate was also observed earlier with the standard diet than with fatty diet. The plasma theophylline concentrations produced after both diets were insufficient to produce any detectable change in subjective symptoms like tremor palpitation, heart burn, nausea, restlessness and tenseness. However, theophylline after fatty breakfast was better tolerated than that after a standard breakfast.