angiotensin - converting enzyme ( ace ) inhibitors have been increasingly used for the therapeutic management of several conditions , such as hypertension , acute myocardial infarction , left ventricular systolic dysfunction , chronic renal failure , and so on . large multicentric trials have proved that ace inhibitors not only increase the life expectancy , but also improve the quality of life in high - risk patients suffering from cardiovascular events . ace inhibitors have specific effect on myocardial and vascular cell growth , also referred to as remodeling , they have a greater protective potential than any other class of antihypertensive drugs . very few studies have conducted to evaluate the occurrence of adrs due to ace inhibitors . reporting of adrs has become an important component of monitoring and evaluation activities performed in hospitals . such adr reporting programs encourage surveillance for adrs , promote the reporting of adrs , and stimulate the education of health professionals regarding potential adrs . intensive monitoring study will help in obtaining detailed data on incidence and pattern of adrs . the present study was designed to evaluate the incidence and pattern of adrs due to ace inhibitors in the cardiology department . a cross - sectional observational study was carried out for the period of 6 months ( january  june 2010 ) in an indian teaching hospital . the ethical approval was obtained from institutional ethics committee prior to study initiation ( uec/19/2010 ) . prescription from each patient during his / her hospitalization in the ward during the study period was included . the information such as demographics , complaints on admission , routine biochemical investigations , were obtained from the patient 's clinical records . details necessary for evaluations regarding previous allergies , concomitant medications , comorbidities , and others were collected . all drugs were classified with anatomical therapeutic chemical classification ( atc code  level 1 , who , 2008 ) . factors studied were ( a ) patient characteristics [ gender , age ( > 18 years ) , comorbidities and length of stay ] , ( b ) drug characteristics [ number of drugs ] and laboratory investigations . identification of adrs were done based on the regular follow of the patients by analyzing the subjective findings like cough , and objective findings like routine monitoring of electrolytes , blood pressure , and serum creatinine . data on the reported adrs were evaluated to understand the pattern of the adrs with respect to patient demographics , nature of the reaction , characteristics of the drugs involved , and outcome of the reactions . causality : in order to assess the likelihood that drugs has caused the reaction , causality assessment was done using naranjo 's adr probability scale whereby the adrs were classified into certain , probable , possible , and unlikely to be drug induced depending upon the level of association . severity : depending upon the severity , adrs were classified into mild , moderate , and severe reactions using the criterion developed by hartwig et al . for severity assessment . preventability : adrs were categorized into definitely preventable , probably preventable , and not preventable using the criteria of schumock and thornton modified . predisposing factors : factors which could have predisposed to the occurrence of adrs in the individual reports were evaluated . predisposing factors were generally classified for the purpose of study into age , gender , multiple and intercurrent disease state , and polypharmacy . management strategies employed for the management of adrs were categorized as drug withdrawal , dose reduction , additional treatment for adr , and no change in regimen with any additional treatment . further , categorization of the outcome of adrs was done for response after dechallenge and rechallenge as well as the final outcome of the event . frequencies with percentage were used to summarize sex , number of drugs dispensed , frequency of adrs , drugs involved in the adrs , and severity of adrs . the chi - square test was used to find the association between sex , number of drugs , and adrs . spearman 's correlation was used to find the correlation between numbers of drugs , length of stay with adrs . the information such as demographics , complaints on admission , routine biochemical investigations , were obtained from the patient 's clinical records . details necessary for evaluations regarding previous allergies , concomitant medications , comorbidities , and others were collected . all drugs were classified with anatomical therapeutic chemical classification ( atc code  level 1 , who , 2008 ) . factors studied were ( a ) patient characteristics [ gender , age ( > 18 years ) , comorbidities and length of stay ] , ( b ) drug characteristics [ number of drugs ] and laboratory investigations . identification of adrs were done based on the regular follow of the patients by analyzing the subjective findings like cough , and objective findings like routine monitoring of electrolytes , blood pressure , and serum creatinine . data on the reported adrs were evaluated to understand the pattern of the adrs with respect to patient demographics , nature of the reaction , characteristics of the drugs involved , and outcome of the reactions . causality : in order to assess the likelihood that drugs has caused the reaction , causality assessment was done using naranjo 's adr probability scale whereby the adrs were classified into certain , probable , possible , and unlikely to be drug induced depending upon the level of association . severity : depending upon the severity , adrs were classified into mild , moderate , and severe reactions using the criterion developed by hartwig et al . for severity assessment . preventability : adrs were categorized into definitely preventable , probably preventable , and not preventable using the criteria of schumock and thornton modified . predisposing factors : factors which could have predisposed to the occurrence of adrs in the individual reports were evaluated . predisposing factors were generally classified for the purpose of study into age , gender , multiple and intercurrent disease state , and polypharmacy . management strategies employed for the management of adrs were categorized as drug withdrawal , dose reduction , additional treatment for adr , and no change in regimen with any additional treatment . further , categorization of the outcome of adrs was done for response after dechallenge and rechallenge as well as the final outcome of the event . frequencies with percentage were used to summarize sex , number of drugs dispensed , frequency of adrs , drugs involved in the adrs , and severity of adrs . the chi - square test was used to find the association between sex , number of drugs , and adrs . spearman 's correlation was used to find the correlation between numbers of drugs , length of stay with adrs . a total of 692 patients who were prescribed with ace inhibitors were analyzed during the study period in cardiology unit and 51 ( 7.36% ) patients had developed 60 adrs . the significant proportions of patients with adrs were female 48 ( 80% ) than in male 12 ( 20% ) . a total of 35 ( 58.33% ) adrs were developed mostly in the age group of > 61 years , followed by the other age group and the patients who had taken more than 7 drugs developed 54 ( 90% ) adrs . a total of 37 ( 61.66% ) adrs were developed with a length of hospital stay of > 14 days , followed by 23 ( 38.33% ) with < 7 days . the age , sex , and number of drugs taken were identified as the risk factors for developing adrs ( p<0.05 ) . spearman correlation showed that there was an extremely significant linear relationship ( r=0.16 , 95% ci=2.4113.44 , p<0.000 ) was observed between number of drugs taken and adrs . similarly , a significant linear relationship ( r=0.08 , 95% ci=1.03 - 3.82 , p<0.036 ) between sex and the adrs in patients and linear relationship ( r=0.09 , 95% ci=0.300.91 , p<0.022 ) between age and the adrs in patients . ramipril 27 ( 45% ) , enalapril 18 ( 30.00% ) , captopril 11 ( 18.33% ) , and linisopril 4 ( 6.64% ) were the most commonly observed drugs involved and the common adrs observed were cough 23 ( 38.33% ) , hyperkalemia 19 ( 31.66% ) , hypotension 13 ( 21.66% ) , and acute renal failure 05 ( 8.33% ) . incidence of individual suspected drugs with their adrs results are summarized in the table 2 . patient characteristics incidence of individual suspected drugs with their adverse drug reactions present data on adrs were evaluated for the specific system affected by adrs . respiratory disorders due to cough were 23 ( 38.33% ) , followed by metabolic and nutritional disorders due to hyperkalemia 19 ( 31.66% ) , which is presented in table 3 . organ system affected by the adverse drug reactions in majority , 47 ( 78.33% ) of the cases , the suspected drug was withdrawn for the management of the adrs and a specific treatment for the reaction was instituted in 20 ( 33.33% ) . in 56 ( 93.33% ) of the cases , the patient recovered from the reaction at the time of evaluation of the adr report . an improvement in the adverse reaction was observed in majority ( 76.8% ) of the cases , in which dechallenge or dose reduction was done [ table 4 ] . upon causality assessment , majority of the reports were rated as probable 56 ( 93.33% ) followed by possible 4 ( 06.66% ) . a total of 13 ( 21.66% ) of reactions were mild and moderate reactions accounted for 47 ( 78.33% ) . a total of 692 patients who were prescribed with ace inhibitors were analyzed during the study period in cardiology unit and 51 ( 7.36% ) patients had developed 60 adrs . the significant proportions of patients with adrs were female 48 ( 80% ) than in male 12 ( 20% ) . a total of 35 ( 58.33% ) adrs were developed mostly in the age group of > 61 years , followed by the other age group and the patients who had taken more than 7 drugs developed 54 ( 90% ) adrs . a total of 37 ( 61.66% ) adrs were developed with a length of hospital stay of > 14 days , followed by 23 ( 38.33% ) with < 7 days . the age , sex , and number of drugs taken were identified as the risk factors for developing adrs ( p<0.05 ) . spearman correlation showed that there was an extremely significant linear relationship ( r=0.16 , 95% ci=2.4113.44 , p<0.000 ) was observed between number of drugs taken and adrs . similarly , a significant linear relationship ( r=0.08 , 95% ci=1.03 - 3.82 , p<0.036 ) between sex and the adrs in patients and linear relationship ( r=0.09 , 95% ci=0.300.91 , p<0.022 ) between age and the adrs in patients . ramipril 27 ( 45% ) , enalapril 18 ( 30.00% ) , captopril 11 ( 18.33% ) , and linisopril 4 ( 6.64% ) were the most commonly observed drugs involved and the common adrs observed were cough 23 ( 38.33% ) , hyperkalemia 19 ( 31.66% ) , hypotension 13 ( 21.66% ) , and acute renal failure 05 ( 8.33% ) . incidence of individual suspected drugs with their adrs results are summarized in the table 2 . respiratory disorders due to cough were 23 ( 38.33% ) , followed by metabolic and nutritional disorders due to hyperkalemia 19 ( 31.66% ) , which is presented in table 3 . in majority , 47 ( 78.33% ) of the cases , the suspected drug was withdrawn for the management of the adrs and a specific treatment for the reaction was instituted in 20 ( 33.33% ) . in 56 ( 93.33% ) of the cases , the patient recovered from the reaction at the time of evaluation of the adr report . an improvement in the adverse reaction was observed in majority ( 76.8% ) of the cases , in which dechallenge or dose reduction was done [ table 4 ] . upon causality assessment , majority of the reports were rated as probable 56 ( 93.33% ) followed by possible 4 ( 06.66% ) . a total of 13 ( 21.66% ) of reactions were mild and moderate reactions accounted for 47 ( 78.33% ) . our study revealed that the overall incidence of aceis - induced adrs in the study populations were 7.367% which is low , compared to similar studies . a total of 58.33% of adrs were observed in the age group of more than 61 years and considering the result of the chi - square test for analytical evaluation of the influence of age on occurring adrs , it appears that older patients are more likely to experience an adr . moore et al . found an inverse relationship between age and adrs occurring during hospital stay . altered physiology in geriatrics could be another reason for higher incidence of adrs in the population . while considering the gender distribution , there was increased number of adrs present in women than men , which is similar to some earlier reported studies . several studies have found that risk of developing adrs was more in females than males . reasons suggested for this include differences in perception of adrs , pharmacology of adrs , differences in pharmacokinetics such as volume of distribution , polypharmacy , and hormonal differences between men and women . the incidence of adrs was more in the population receiving seven or more medications concurrently , which is supported by previously published studies . our results show that drugs like ramipril 45% and enalapril 30% had the higher incidence of adrs and the common adrs observed were found to be cough 38.33% , hyperkalemia 31.66% , and acute renal failure 8.33% and these results were similar to other studies conducted in various university hospitals.[2022 ] drug withdrawal or dose reduction is usually the first step to be employed for the management of an adr . in 78.33% of the cases , the suspected drug was withdrawn and dose reduction was done in 22.2% of cases . considering the final outcome , 93.33% of patients were recovered from adrs , whereas 6.66% of patients were continuing and these findings were similar to the one observed by suh et al . in their study patients . on causality assessment of adrs , majority of the reactions 93.33% were categorized as probable in nature , followed by possible 6.70% . considering the severity assessment of the reactions , majority of the reactions were categorized moderate in nature followed by mild and these findings were not comparable with the spontaneous reporting study . preventability assessment of adrs showed that 8.33% of the adrs were not preventable in nature . definitely preventable adrs were not present in this study compared to the study conducted on adverse drug reaction to cardiovascular drugs , where 1.9% of adrs were preventable . drug withdrawal or dose reduction is usually the first step to be employed for the management of adrs .