Mehreen

Pharmacology & Pharmacy, 2014, 5, 401-407 Published Online April 2014 in SciRes. http://www.scirp.org/journal/pp http://dx.doi.org/10.4236/pp- Possibility of Drug-Drug Interaction in Prescription Dispensed by Community and Hospital Pharmacy Huda Kafeel*, Ramsha Rukh, Hina Qamar, Jaweria Bawany, Mehreen Jamshed, Rabia Sheikh, Tazeen Hanif, Urooj Bokhari, Wardha Jawaid, Yumna Javed, Yamna Mariam Saleem Faculty of Pharmacy, Jinnah University for Women, Karachi, Pakistan Email:-Received 7 February 2014; revised 21 March 2014; accepted 7 April 2014 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Objective: To analyze the use of all subsidized prescription drugs including their use of drug combination generally accepted as carrying a risk of severe interactions. Methodology: In a cross sectional study, we analyzed all prescriptions (n = 1014) involving two or more drugs dispensed to the population (age range 4 - 85 years) from all pharmacies, clinics and hospitals. Data were stratified by age and sex, and frequency of common interacting drugs. Potential drug interactions were classified according to clinical relevance as significance of severity (types A: major, B: moderate, and C: minor) and documented evidence (types 1, 2, 3, and 4). Result and Discussion: The growing use of pharmacological agents means that drug interactions are of increasing interest for public health. Monitoring of potential drug interactions may improve the quality of drug prescribing and dispensing, and it might form a basis for education focused on appropriate prescribing. To make the manifestation of adverse interaction subside, management strategies must be exercised if two interacting drugs have to be taken with each other, involving: adjusting the dose of the object drug; spacing dosing times to avoid the interaction. The pharmacist, along with the prescriber has a duty to ensure that patients are aware of the risk of side effects and a suitable course of action they should take. Conclusion: It is unrealistic to expect clinicians to memorize the thousands of drug-drug interactions and their clinical significance, especially considering the rate of introduction of novel drugs and the escalating appreciation of the importance of pharmacogenomics. Reliable regularly updated decision support systems and information technology are necessary to help avert dangerous drug combinations. Keywords Drug-Drug Interaction; Adverse Drug Reaction; Polypharmacy * Corresponding author. How to cite this paper: Kafeel, H., Rukh, R., Qamar, H., Bawany, J., Jamshed, M., Sheikh, R., Hanif, T., Bokhari, U., Jawaid, W., Javed, Y. and Saleem, Y.M. (2014) Possibility of Drug-Drug Interaction in Prescription Dispensed by Community and Hospital Pharmacy. Pharmacology & Pharmacy, 5, 401-407. http://dx.doi.org/10.4236/pp- H. Kafeel et al. 1. Introduction Drug-drug interactions (DDIs) have received a great deal of recent attention from the regulatory, scientific, and health care communities worldwide [1]. A drug interaction is defined as the pharmacologic or clinical response to the administration of a drug combination differing from that anticipated from the known effect of the 2 agents [2]. A clinically significant interaction between 2 drugs is said to have occurred when the therapeutic or toxic effect of one drug is altered as a consequence of co-administration of another drug. Some knowledge of the pharmacological basis of how one drug may change the action of another is useful in obtaining those interactions that are wanted, as well as in recognizing and preventing those that are not [3]. There are different types of interaction. Interaction that may result in a change in the nature or type of response to a drug is pharmacodynamic interaction [2]. Pharmacokinetic interactions encompass alterations in ADME (Absorption, Distribution, Metabolism, Excretion). Pharmacokinetic DDIs are indirect in that the perpetrator either inhibits or induces the metabolic clearance of the substrate object drug which results in augment or reduces the clinical effect of object drug due to change in systemic plasma concentration [4]. Pharmacoepidemiologic studies, mostly carried out in Europe and the Americas, have found varying rates of potential DDIs, ranging from 5% to 80% [5]-[8]. Factors that have shown consistent association with the presence of potential DDIs in previous studies included polypharmacotherapy [9]-[12], age [2] [10], gender, main diagnosis and medication and the number of physicians that a patient visits, [13]-[15]. Studies conducted in various mainly western countries on incidence and causes of prescribing potentially hazardous drug combinations in general practice [16] [17] and potential determinants of drug-drug interactions associated dispensing in community pharmacies [18]. With present observational study, we evaluated the prevalence of drug-drug interactions among the dispensed medications in the vicinity of Karachi. We have utilized the database [19] to check the interactions and evaluated the risk as major, moderate and minor. And different factors that are significantly associated with the possibility of potential DDIs were also been study. 2. Methodology In our cross sectional study, we analyzed prescriptions involving two or more drugs dispensed to the population (age range 4 - 85 years) from different areas of Karachi (n = 1014). The total study sample of 1014 prescriptions was randomly stratified by age group sex, and frequency of common interacting drugs, presence and severity of interactions. We have utilized the database to check drug-drug interactions from the drugs.com website as previously utilized by Stephany Duda in 2005 [20]. We excluded incomplete prescriptions. Further we classified them on the basis of mechanism of interaction, severity of interaction as major, moderate and minor, presence of mono or Polypharmacy etc. All these data is gathered, analyzed and presented in the form of tables and graphs as frequencies and percentages. Significant associations are also analyzed by using standard statistical method on SPSS version 21 (Figure 1). 3. Results and Discussion In a total of 1014 prescriptions we have found n = 608 (60%) prescriptions without any DDI and remaining n = 406 (40%) had at least one interacting combination with 13% major, 17% moderate and 10% minor interactions (Figure 2). Potential drug interactions were classified according to clinical relevance as significance of severity as (types A: major, B: moderate, and C: minor) and documented evidence (types 1, 2, 3, and 4)—for example, subtype C4 indicates an minor interaction with greater potential clinical relevance than that classified as subtype C1 and thus A4 subtypes were marked as lethal and life threatening to the patients and needs strict interventions. Clinically relevant minor potential drug interactions that could be controlled by adjusting the dose (type C) were found in 8.1%. Potential interactions that might have serious clinical consequences (type A) were found in 2.8% of the prescriptions. Of the potential type focal interactions were between potassium supplements and potassium sparing diuretics—a combination that may result in severe and even life threatening hyperkalaemia [21] [22]. With the increased availability of new drugs and their concomitant use with other drugs, there has been a rise in the potential for adverse drug interactions as demonstrated by the recent withdrawals of newly marketed drugs because of unacceptable interaction profiles. Therefore, the interaction potential of a novel compound has to be evaluated in detail, preliminary with preclinical in vitro and in vivo exercises at candidate selection and conti- 402 H. Kafeel et al. Figure 1. Flowchart representation of methodology. 10% 17% 60% 13% No interaction presnt Major Moderate Minor Figure 2. Presence of potential drug-drug interactions. nuously followed up through preclinical and clinical development [21]. Different variables that are in close association with potential DDIs are summarized in Table 1. Poly pharmacy is use of multiple medications (as using ≥3 drugs) has been shown to drug-drug interactions particularly in the geriatric population [21] [23]. When presence of drug interactions were cross tabulated with age groups of patients, a highly significant relationship is found with p 2 or