Assess the frequency and severity of adverse drug reactions due to errors in drug intake at a tertiary care hospital

G. Shivaprakash, Praveen Ravi, Sanjay Hadigal, L. C. Pallavi


Background: Drug-related problems are an important cause of morbidity and mortality and a significant burden on healthcare resources. There are few studies to account for errors in drug intake leading to adverse drug reactions (ADRs). This study was pursued with the objective of determining the frequency and severity of the ADRs resulting from erroneous drug intake, the expenses incurred in treating the same.

Methods: The study was a prospective, cross-sectional, observational study. The study subjects were patients with ADRs due to errors in drug intake and from self-medication. All the information regarding the ADR were collected as per ADR reporting form issued by Central Drugs Standard Control Organization. Causality was assessed by both Naranjo and the WHO criteria for causality assessment. Direct cost of all the medications, hospital charges (admission, bed charges, consultations paid, treatment charges, investigations, and conveyance charges) were recorded to find the financial burden due to error in drug intake.

Results: The study showed that nearly 30% of the ADRs were due to errors in drug intake and the major contributing factor is self-modification either by discontinuation or missed doses. Major drugs that are implicated in these ADRs were that of metformin and insulins among anti-diabetic drugs and amlodipine and atenolol among antihypertensives. These two groups contributed to 18 (62%) of the total 29 ADRs. Organ system commonly involved was central nervous system and that was followed by musculoskeletal system. The average direct cost incurred in the management of these ADRs was Rs. 5773 for non-serious adverse events (SAE’s) and Rs. 11,400 for SAE’s.

Conclusion: Proper education about the importance of compliance and damaging consequences of self-modification of drug dosage in patients who are on treatment for chronic disorders like diabetes and hypertension will be an effective strategy to prevent many of these ADRs.


Errors, Adverse drug reactions, Self-medication

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