The profile of voluntary reported adverse drug reactions at a tertiary care hospital: a fifteen month prospective study.

OBJECTIVES: The present study was undertaken to provide the health professionals who were working at a tertiary care hospital, with a simple method to report Adverse Drug Reactions (ADRs) and to monitor, document and to evaluate them according to the set criteria. METHOD AND MATERIALS: This study was conducted over a period of 15 months from 1st Jan' 2008 to 31st March 2009 at Goa Medical College and Hospital (Goa, India). The evaluation of the data was done for various parameters, which included patient demographics and drug and reaction characteristics. An assessment was also done for the outcome, causality and the severity of the drug reactions. RESULTS: A total of 265 ADRs were reported. Among the drugs, the ß-lactam antibiotics were implicated the maximum number of times (54, 20.37%), followed by fluoroquinolones (35, 13.20%), antiretrovirals (33, 12.45%) and antiepileptics (31, 11.69%). Females showed more ADRs (142, 54%) than males (123, 46%). The skin was involved in about 57.73% (153) of the ADRs, while the CNS and the vascular system were involved in 8.67% (23) and 8.30% (22) of the ADRs. Most of the ADRs were categorized as "Type II" (203, 77%) against "Type I" (62, 23%) by Rawlins and Thompson's classification. The causality assessment was done by the Naranjo Algorithm and 62.26% (165) were seen to fall in the "probable category" as compared to 29.05% (77) in the "highly probable" one. Out of all the ADRs which were reported, 34.71% (148) were "severe", in accordance with the Modified Hartwig and Siegel's scale. CONCLUSION: The present work was a humble attempt to set up a well organized ADR reporting system at our government hospital. The systematic tracking and monitoring of ADRs can shed light on their extensiveness and their patterns of occurrence.

Aggravating action of hydralazine on ethanol-induced gastric lesions.

Endogenous nitric oxide has been proposed as one of the mediators of gastric cytoprotection. We studied the effect of the vasodilator hydralazine which acts via nitric oxide and thus is expected to have a gastroprotective action. However, hydralazine aggravates ethanol-induced gastric lesions. This effect is not influenced by pretreatment with the selective alpha 1 adrenergic antagonist prazosin but is abolished by the angiotensin converting enzyme inhibitor, captopril suggesting the involvement of the renin-angiotensin system.

Protective effect of propranolol on ethanol-induced gastric lesions in rats: probable mechanism of action.

The non-selective beta-adrenoceptor antagonist, propranolol, has been reported to protect against gastric injury in mice, an effect only partly due to prostaglandin release. This study was designed to confirm the gastric cytoprotective effect of propranolol in another species of animal, the rat, and investigate further its mechanism of action. Our results show that propranolol prevents both ethanol-induced gastric lesions as well as ethanol-induced contraction of the circular muscle of rat fundic strip. The local anaesthetic, lignocaine also inhibited the effect of ethanol on circular muscle. However, timolol, another non-selective beta-adrenoceptor antagonist, failed to produce such an action. The effect of propranolol was abolished by the cyclooxygenase inhibitor, indomethacin and a high dose of the guanylate cyclase inhibitor, methylene blue. The results suggest that in addition to prostaglandins, endogenous nitric oxide and the membrane stabilising action of propranolol may also be involved in its gastroprotective action.

Dual action of clonidine on ethanol-induced gastric lesions: is the imidazoline-preferring receptor involved?

The imidazole alpha 2-adrenoceptor agonist, clonidine, exerts a dual action on ethanol-induced gastric lesions. At lower doses, it has a gastroprotective effect which is also seen with two other alpha 2-adrenoceptor agonists - the catecholamine, alpha-methyldopa and the guanidine, guanabenz. The gastroprotective action of the three drugs is prevented by the selective alpha 2-adrenoceptor antagonist, yohimbine, suggesting that the action is mediated by alpha 2-adrenoceptors. However, at higher doses clonidine aggravates ethanol-induced gastric lesions, an effect also seen with another imidazole, oxymetazoline. The aggravating action is not prevented by yohimbine and is not seen with alpha-methyldopa and guanabenz. This suggests that it involves a receptor/mechanism other than alpha 2- possibly an imidazoline-preferring receptor but further work, including radioligand binding studies, is needed to confirm this.

Aggravating action of clonidine on ethanol-induced gastric lesions: probable mechanism of action.

Large doses of the imidazoline alpha 2 adrenoreceptor agonist clonidine aggravate ethanol-induced gastric lesions. The alpha 2 adrenoceptor antagonist phentolamine, the opioid antagonist naloxone and the H2 antagonist cimetidine do not prevent this action of clonidine suggesting that it is not mediated by alpha 2, opioid or H2 receptors. Further, like clonidine, high doses of phentolamine and cimetidine aggravate gastric lesions per se, suggesting that all three may be acting at a common 'receptor' site, possibly the imidazoline-preferring receptor (IPR).