Underlying diseases, including renal failure (serum creatinine >2), myocarditis and arrhythmia, anemia (hemoglobin<4-8), lower respiratory tract infection, and asthma Patients requiring intubation or frequent use of respiratory drugs Severe and critical patients History of allergy to studied drug Pregnancy and breastfeeding

Underlying diseases, including renal failure (serum creatinine >2), myocarditis and arrhythmia, anemia (hemoglobin<4-8), lower respiratory tract infection, and asthma Patients requiring intubation or frequent use of respiratory drugs Severe and critical patients History of allergy to studied drug Pregnancy and breastfeeding