Idiosyncratic Adverse Reactions of Most Frequent Drug Combinations Longterm Use Among Hospitalized patients with Polypharmacy

Abstract

Inappropriate prescribing of a multiple therapeutic agents to patients with chronic conditions is very common in everyday practice. Adverse drug reactions (ADRs) are still considered as one of the main problems of drug therapy. We investigated idiosyncratic symptoms and signs of adverse drug reactions (ADRs) of the most frequent used combination of drugs among hospitalized patients prescribed polypharmacy. A cross sectional study (design) was performed in Pharmacies "Eufarm Edal" in Tuzla from 2010 to 2011. Polypharmacy was defined as using > or =4 drugs. The total study sample of 166 examiners was interviewed with a questionnaire about ADRs which was developed special for study. Linear regression analyses was used to evaluate predictors of idiosyncratic signs of adverse drug reactions of the most prevalent drug combinations; using length of drugs in cases polypharmacy more than 6 months as independent variable. Age, sex, index of cumulative morbidity, drug number in polypharmacy, type of drug combination related pharmacological effects, type of hospital clinics were used as possible confounders. The most common exposures to various drug combinations were: medication for high blood pressure and heart (62%), psychotropic drugs (59%), antacids (47%) and antibiotics (46%) among hospitalized patients with polypharmacy. Our results indicated that from 9.6% to 90.4% of hospitalized patients with polypharmacy had at least one suspicious long-term idiosyncratic drug combination use symptoms. The ADRs prevalence often used psychotropic drug combination was initiated suspected idiosyncratic adverse reactions: confusion, depression, anxiety, decreased libido and insomnia. Linear regression analyses also showed that it remains a very strange, and negative idiosyncratic and lacking therapeutic effects of use of antacids in conditions of polypharmacy. The toxicity of some drug combinations may sometimes be synergistic and be greater than the sum of the risks of toxicity of either agent used alone. In order to recognize and to prevent ADRs (including drug interactions), good communication between pharmacist and patient and/or physicians and patient is crucial, and prescribers should develop an effective therapeutic partnership with the patient and with fellow health professionals.