Myocarditis left shoulder and back pain can be treated with analgesics such as codeine, in addition to treatment for myocarditis such as metoprolol. The use of drugs should be under the guidance of a physician or pharmacist. Myocarditis is an inflammatory lesion of the heart muscle, which can be caused by bacteria, viruses, allergies, rheumatic fever and other factors, and viral myocarditis is the most common. Myocarditis may present with symptoms such as palpitations, chest pain or even shoulder pain, edema, etc. In severe cases, cardiogenic shock may occur. Left shoulder pain in myocarditis can be treated with analgesic drugs such as codeine. The drug may cause slow breathing and other discomforts, and is contraindicated for allergy sufferers, breastfeeding women and others. Myocarditis treatment is also required, such as antiarrhythmic treatment with metoprolol. The drug may cause palpitations etc. and is contraindicated in patients with cardiogenic shock etc. If you are diagnosed with myocarditis and have left shoulder pain or other discomfort, please go to the hospital in time, use the medication under the guidance of the physician, pay attention to bed rest and eat foods rich in vitamins and proteins. Avoid aggravation of the condition.