| Abstract |
Introduction and Objectives
Patient self- reporting of Adverse Drug Reactions (ADRs) was found to be valuable to the current pharmacovigilance system by health professionals. Statins, frequently prescribed lipid- lowering drugs for cardiovascular diseases, have significant adverse symptoms that patients could detect perceptibly. This study aimed to explore adverse reactions related to statins and to assess the accuracy of reported symptoms by patients. The association between patients' reports and laboratory tests were also evaluated.
Methods
This cross-sectional study was performed in Srinagarind hospital and Queen Sirikit Heart Center between September 2011 and March 2012. Self-reporting ADR questionnaires were distributed directly by pharmacist or by post to out- patients who were prescribed statins (simvastatin, atorvastatin, or rosuvastatin). The questionnaire collected patients’ demographic characteristics and previously validated checklist of symptoms related to ADRs. Medical records and hospital computer system were reviewed to confirm medication, medical history and laboratory tests. All symptoms were evaluated for causal relationship to statins, based on predefined criteria which considered concomitant drugs and diseases.
Results
A total of 1388 questionnaires were distributed to patients who then completed 718 (51.7%) valid questionnaires suitable for analysis. The prevalence of reported symptoms for the three statins ranged between 74.9 - 76.6%. The most common reported symptoms in simvastatin, atorvastatin and rosuvastatin users were blurred vision (23.2%), loss of memory (9.5%), and muscle pain (11.2%), respectively. Assessment of reported symptoms could classified as true ADRs (n=2,763; 69.0%) and false ADRs (n= 1,241; 31.0%), and the accuracy of reports were significantly related to numbers of reported symptoms (p= 0.030) and types of statins (p< 0.001). Laboratory tests had no significant relationships between reporters and non- reporters of muscle or liver- related adverse symptoms. There were 54.6% of all reported patients who had reported symptoms to their doctors and 58.0% of all discontinued patients had stopped taking statins because adverse reactions occurred.
Conclusions
Patient self- reporting of ADRs is beneficial with reasonable rate of true reported symptoms. Initiating patients to observe adverse symptoms is essential for early detection because liver and muscle enzyme are not generally performed in routine practice. To improve the accuracy of patients' reports, patient- friendly assessment tool should be incorporated with this reporting system.
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Publication
Journal Publication
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