Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Potential Drug-Drug Interactions in Psychiatric Ward of a Tertiary Care Hospital: Prevalence, Levels and Association with Risk Factors

Mohammad Ismail¹, Zafar Iqbal¹ , Muhammad Bilal Khattak², Arshad Javaid³, Muhammad Imran Khan⁴, Tahir Mehmood Khan⁵, Syed Muhammad Asim⁶

¹Department of Pharmacy, University of Peshawar, Peshawar; ²Ayub Teaching Hospital (ATH), Abbottabad; ³Post Graduate Medical Institute (PGMI), Lady Reading Hospital (LRH), Peshawar; ⁴Ayub Medical College, Abbottabad, KPK, Pakistan; ⁵College of Clinical Pharmacy, King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; ⁶Department of Statistics, University of Peshawar, Peshawar, KPK, Pakistan.

For correspondence:- Zafar Iqbal Email: zafariqbal@upesh.edu.pk Tel:+92919216750

Received: 12 July 2011 Accepted: 23 February 2012 Published: 24 April 2012

Citation: Ismail M, Iqbal Z, Khattak MB, Javaid A, Khan MI, Khan TM, et al. Potential Drug-Drug Interactions in Psychiatric Ward of a Tertiary Care Hospital: Prevalence, Levels and Association with Risk Factors. Trop J Pharm Res 2012; 11(2):289-296 doi: 10.4314/tjpr.v11i2.17

© 2012 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To identify the prevalence of potential drug-drug interactions (pDDIs) in a psychiatric ward, their levels and association with risk factors.

Methods: This study was conducted in the psychiatric ward of Ayub Teaching Hospital, Abbottabad, Pakistan. Medical records of 415 patients were retrospectively reviewed for pDDIs using Micromedex Drug-Reax software. Logistic regression was applied to determine association of pDDIs with age, gender, hospital stay and number of drugs.

Results: In our study, we identified total number of 825 pDDIs of 126 types, with median number of 1 pDDIs per patient. Overall 64.8 % of the patients had at least one pDDI; 27.2 % at least one major pDDI; and 58.5 % patients at least one moderate pDDI. Among 825 identified pDDIs, most were of moderate (75.6 %) or major (20.8 %) severity, good (66.4 %) or fair (29 %) type of scientific evidence; and delayed onset (71 %). The most frequent major and moderate pDDIs included haloperidol + procyclidine (127 cases), haloperidol + olanzapine (49), haloperidol + promethazine (47), haloperidol + fluphenazine (41), diazepam + divalproex sodium (40), haloperidol + trihexyphenidyl (37), lorazepam + divalproex sodium (34), fluphenazine + procyclidine (33) and olanzapine + divalproex sodium (32). There was significant association of occurrence of pDDIs with hospital stay of 7 days or longer (p = 0.005) and taking 7 or more drugs (p < 0.001).

Conclusion: A high prevalence of pDDIs in the psychiatric ward was recorded, a majority of which were of moderate severity. Patients with long hospital stay and increased number of drugs were more exposed to pDDIs.

Keywords: Drug-drug interactions, Potential drug-drug interaction, Prescriptions screening, Drug-related problems, Clinical pharmacy