A study of adverse drug reactions due to antihypertensive drugs in a tertiary care teaching hospital

Adverse drug reactions (ADRs) present a serious public health problem that can affect patients, caregivers, pharmaceutical companies, and the health care system as a whole. The objective of the present study was to evaluate Adverse Drug Reactions associated with antihypertensive drugs. The present study was an open, non-comparative, observational study was done to monitor ADRs associated with antihypertensive medicines in a university teaching hospital. A total of 34 adverse drug reactions were observed in 250 hypertensive patients during the four month study. A high percentage of adverse drug reactions occurred in middle aged and female patients. Of the 34 adverse drug reactions, 18 (52.9%) were mild, 14 (41.2%) moderate and only 2 (5.8%) were classified as severe. Combination therapy was associated with significantly high occurrence (P < 0.05) of adverse drug reactions, with a total of 21 (61.8%) as compared to monotherapy (n=13, 38.2%). Cardiovascular adverse drug reactions constituted a major component, followed by gastrointestinal and respiratory complaints. Finally our study presents the adverse drug reaction profile of antihypertensive medicines prescribed in our University Teaching Hospital. Beta-blockers were the drug category associated with majority of adverse drug reactions, followed by angiotensin-converting enzyme inhibitors and calcium channel blockers. Key-Words: Adverse Drug Reaction, Hypertension, Beta-blockers, Angiotensin-converting enzyme inhibitors, Calcium channel blockers. Introduction Hypertension is the medical condition where the systolic blood pressure is more than 140 mm Hg and the diastolic blood pressure is more than 90 mm Hg. It is a chronic disease which is considered to be one of the major public health problems and a significant cardiovascular risk factor. According to the World Health Organization (WHO), each year, at least 7.1 million people die as a result of increased blood pressure. For the treatment of hypertension, a broad range of antihypertensive medications are currently available. Antihypertensive drugs are frequently associated with adverse drug reactions (ADRs) that may limit treatment options and reduce patient adherence, which may hinder blood pressure control. These drugs are believed to cause ADRs or symptoms that make patients feel worse than they did before beginning drug therapy for their "asymptomatic" disease. * Corresponding Author: E-mail: [email protected] Mob.: 91 9994247706 It is thought that different discontinuation rates for various classes of antihypertensive agents are probably related to their different rates of adverse symptoms. Aggressive treatment of hypertension and treating to goal blood pressure can reduce cardiovascular events Achieving blood pressure goals usually requires two or more antihypertensive drugs; however; increasing the number of antihypertensive drugs in a regimen may lead to even more adverse effects. It is estimated that the prevalence of hypertension in India is about 25% among urban adults and 10% in the rural areas. The lifetime risk of developing hypertension is estimated to be 90%. 10 According to the World Health Organization (WHO) definition, an adverse drug reaction (ADR) is ‘a response to a drug that is noxious and unintended and occurs at doses normally used in human for the prophylaxis, diagnosis, and treatment of disease, or for modification of physiological function. ADR can also be defined as ‘an appreciably harmful or unpleasant reaction, resulting from an intervention related to the use of a medicinal product, which predicts hazard from future administration and warrants prevention or Research Article [Prasad et al., 2(5): May, 2011]