Occurrence of possible drug related interactions in medical patients in out-patient departments of Pakistan


  • Hammad A. Butt Department of Pharmacology, CMH Kharian Medical College, Kharian, Pakistan
  • Ammara Khan Department of Pharmacology, Nawaz Sharif Medical College, University of Gujrat, Hafiz Hayat Campus, Gujrat, Pakistan
  • Naveed Suleman Department of Pharmacology, University of Health Sciences, Lahore, Pakistan




Adverse drug interaction, Drug-related problems, Drug-drug interaction, Pharmacoepidemiology


Background: Data regarding occurrence of drug-drug interactions in Pakistan is rare. In the current study, we have tried to find out the clinical adversity and frequency witnessed in prescriptions of a medical outpatient department.

Methods: Patient prescriptions were analyzed for potential drug-drug interactions.  A sample of 364 patients, visited outpatient department who were being prescribed at least two drugs simultaneously using a drug interaction program website.

Results: The 364 patients (72.8% male, mean age 57.9±15.2 years) were prescribed a median of six drugs (range 2-13) at OPD visit. Three hundred forty nine patients (95.8%) had at least one potentially interacting drug combination. 2636 potential interactions were seen in the visiting patients. Out of these 124 (4.7%) were of major severity, 1730 (65.6%) moderate and 515 (19.5%). Out of 124 patients with a potential DDI with major severity, no patient was re-hospitalized within 2 months after discharge due to a probable drug-related problem associated with the potential DDI.

Conclusions: A large percentage of patients were detected having one or more potential drug-drug interactions, using drug interaction detection program. However, the percentage of patients having clinically adverse consequences due to drug-drug interactions appears to be very low.

Author Biography

Naveed Suleman, Department of Pharmacology, University of Health Sciences, Lahore, Pakistan

Department of Pharmacology


Pirmohamed M, James S, Meakin S, Green C, Scott AK, Walley TJ, et al. Adverse drug reactions as cause of admission to hospital: prospective analysis of 18 820 patients. BMJ. 2004;329:15-9.

Juurlink DN, Mamdani M, Kopp A, Laupacis A, Redelmeier DA. Drug-drug interactions among elderly patients hospitalized for drug toxicity. JAMA. 2003;289:1652-58.

Lazarou J, Pomeranz BH, Corey PN. Incidence of adverse drug reactions in hospitalized patients: a meta-analysis of prospective studies. JAMA. 1998;279:1200-5.

Tulner LR, Frankfort SV, Gijsen GJ, Van-Campen JP, Koks CH, Beijnen JH. Drug-drug interactions in a geriatric outpatient cohort. Drug & Aging. 2008; 25:343-55.

Magro L, Moretti U, Leone R. Epidemiology and characteristics of adverse drug reactions caused by drug-drug interactions. Expert Opin Drug Saf. 2012;11:83-94.

Pedros C, Quintana B, Rebolledo M, Porta N, Vallano A, Arnau JM. Prevalence, risk factors and main features of adverse drug reactions leading to hospital admission. Eur J Clin Pharmacol. 2014; 70:361-7.

Ismail M, Iqbal Z, Khattak MB, Khan MI, Arsalan H, Javaid A, et al. Potential drug–drug interactions in internal medicine wards in hospital setting in Pakistan. Int J Clin Pharm. 2013;35:455-62.

Carvalho RE, Reis AM, Faria LM, Zago KS, Cassiani SH. Prevalence of drug interactions in intensive care units in Brazil. Acta paul enferm. 2013;26:150-7.

Ismail M, Iqbal Z, Khan MI, Javaid A, Arsalan H, Farhadullah H, et al. Frequency, levels and predictors of potential drug-drug interactions in a pediatrics ward of a teaching hospital in Pakistan. Trop J Pharm Res. 2013;12:401-6.

Rafi MS, Naqvi SB, Khan MU, Fayyaz M, Ashraf N, Khan MA, et al. Evaluation of potential drug-drug interactions with antidepressants in two tertiary care hospitals. J Clin Diagn Res. 2015;9:FC05-8.

Vandael E, Marynissen T, Reyntens J, Spriet I, Vandenberghe J, Willems R, et al. Frequency of use of QT-interval prolonging drugs in psychiatry in Belgium. Int J Clin Pharm. 2014;36:757-65.

Van-Leeuwen RW, Brundel DH, Neef C, Van-Gelder T, Mathijssen RH, Burger DM, et al. Prevalence of potential drug–drug interactions in cancer patients treated with oral anticancer drugs. Br J Cancer. 2013;108:1071-8.

Chelkeba L, Alemseged F, Bedada W. Assessment of potential drug-drug interactions among outpatients receiving cardiovascular medications at Jimma University specialized hospital, south West Ethiopia. Int J Basic Clin Pharmacol. 2013;2:144-52.

Feinstein J, Dai D, Zhong W, Freedman J, Feudtner C. Potential drug−drug interactions in infant, child, and adolescent patients in Children’s hospitals. Pediatrics. 2015;135:e99-108.

Patel PS, Rana DA, Suthar JV, Malhotra SD, Patel VJ. A study of potential adverse drug-drug interactions among prescribed drugs in medicine outpatient department of a tertiary care teaching hospital. J Basic Clin Pharm. 2014;5:44-8.

Chavda NB, Solanky PP, Baria H, Naik R, Bharti K. Study of potential drug–drug interaction between prescribed drugs in patients attending outpatient department of medicine at tertiary-care hospital in South Gujarat region. Natl J Physiol Pharm Pharmacol. 2015;5:236-42.

Aparasu R, Baer R, Aparasu A. Clinically important potential drug-drug interactions in outpatient settings. Research in Social and Administrative Pharmacy. 2007;3(4):426-37.

Janchawee B, Wongpoowarak W, Owatranporn T, Chongsuvivatwong V. Pharmacoepidemiologic study of potential drug interactions in outpatients of a university hospital in Thailand. J Clin Pharm Ther. 2005;30:13-20.

Saeed A, Ibrahim H. Reasons for the problems faced by patients in government hospitals: results of a survey in a government hospital in Karachi, Pakistan. J Pak Med Assoc. 2005;55:45-7.

Henriksen K, Battles JB, Keyes MA, Grady ML. Advances in patient safety: new directions and alternative approaches. Agency for Healthcare Research and Quality. Available at: https://www.academia.edu/9612902/Using_Patient_Complaints_to_Promote_Patient_Safety_Agency_for_Healthcare_Research_and_Quality_Advances_in_Patient_Safety_New_Directions_and_Alternative_Approaches_Volume_2_2008. Accessed on 20 June 2020.

Micromedex Database, Truven health analytics, Greenwood Village, Colorado, USA. Available at: https://www.micromedexsolutions.com/micromedex2/librarian. Accessed 24 June 2019.

Jazbar J, Locatelli I, Horvat N, Kos M. Clinically relevant potential drug-drug interactions among outpatients: A nationwide database study. Res Social Adm Pharm. 2018;14(6):572-80.




How to Cite

Butt, H. A., Khan, A., & Suleman, N. (2020). Occurrence of possible drug related interactions in medical patients in out-patient departments of Pakistan. International Journal of Basic & Clinical Pharmacology, 9(10), 1503–1508. https://doi.org/10.18203/2319-2003.ijbcp20204086



Original Research Articles