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

Hammad A. Butt, Ammara Khan, Naveed Suleman


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.


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

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