Tehran University of Medical Sciences Journal of Pharmaceutical Care 2322-4630 8 4 2020 12 28 176 179 Farzaneh Dastan Department of Clinical Pharmacy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran AND Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran. Jamshid Salamzadeh Department of Clinical Pharmacy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Ali Saffaei Student Research Committee, Department of Clinical Pharmacy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Yasaman Nabavi Department of Clinical Pharmacy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohammad Abbasinazari Department of Clinical Pharmacy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2020 04 13 2020 09 26 Backgrounds: Statins are associated with several muscle complaints, such as: myositis, myalgia, muscle weakness, muscle spasms and rhabdomyolysis. Age, race, gender, dose of statin, concomitant medications, concomitant disorders and genetics have been reported as the most important risk factor for statin-induced myalgia. The aim of this study was to determine the prevalence and associated risk factors of atorvastatin-induced myalgia in hospitalized patients in Tehran, Iran. Methods: In this cross sectional study, a questionnaire was developed by expert panel opinions. The questionnaire was included various items regarding demographic data and myalgia evaluation factors. Seven hundred patients were included in the study and necessary data were gathered. Finally, the data were analyzed and a statistical model was designed to predict the myalgia risk factors. Results: The rate of myalgia was 44.3% among studied patients. By developing a multivariate logistic model, female gender (OR= 0.47, P-value<0.001) was one of the most important factors in myalgia occurrence. Conclusion: The results of this study suggest that gender, age, atorvastatin dose, duration of atorvastatin usage and presence of myotoxic disease are the main predictors of myalgia in Iranian population. Hence, the findings of this study can be considered to predict the myalgia incidence risk in Iranian population. https://jpc.tums.ac.ir/index.php/jpc/article/view/337