What is the treatment for secondary muscular infection?

From the Guidelines

Secondary muscle infections require prompt treatment with vancomycin as the initial empirical therapy, along with an agent active against enteric gram-negative bacilli in immunocompromised patients or those with open trauma to the muscles, as recommended by the Infectious Diseases Society of America 1. The treatment of secondary muscle infections, also known as pyomyositis or bacterial myositis, involves broad-spectrum antibiotics that cover Staphylococcus aureus (including MRSA) and streptococci, which are the most common causative organisms.

• Initial empiric therapy should include vancomycin (15-20 mg/kg IV every 8-12 hours) for MRSA coverage, plus an agent active against enteric gram-negative bacilli, such as ceftriaxone (1-2 g IV daily) or cefazolin (1-2 g IV every 8 hours) for other pathogens, as suggested by the guidelines 1.
• For patients with MSSA, cefazolin or antistaphylococcal penicillin (eg, nafcillin or oxacillin) is recommended for treatment, as stated in the guidelines 1.
• Treatment duration is typically 2-3 weeks, depending on clinical response, and antibiotics should be administered intravenously initially, but once the patient is clinically improved, oral antibiotics are appropriate for patients whose bacteremia cleared promptly and those with no evidence of endocarditis or metastatic abscess, as recommended by the guidelines 1.
• For larger abscesses, early drainage of purulent material should be performed, as recommended by the guidelines 1, and surgical drainage or ultrasound-guided aspiration may be necessary alongside antibiotics.
• Patients should rest the affected muscle, apply warm compresses, elevate the limb if possible, and take analgesics for pain management, as part of the overall treatment plan. The guidelines also recommend repeat imaging studies in patients with persistent bacteremia to identify undrained foci of infection, and MRI as the recommended imaging modality for establishing the diagnosis of pyomyositis 1.

From the Research

Secondary Muscle Infection Treatment

• The treatment of secondary muscle infections, particularly those caused by Staphylococcus aureus, depends on the severity of the infection and the susceptibility of the bacteria to antibiotics 2.
• For methicillin-susceptible S. aureus (MSSA) infections, penicillinase-resistant penicillins such as flucloxacillin and dicloxacillin are the antibiotics of choice, while first-generation cephalosporins, clindamycin, lincomycin, and erythromycin may be used for less severe infections or in patients with penicillin hypersensitivity 2.
• For methicillin-resistant S. aureus (MRSA) infections, vancomycin or teicoplanin are recommended for serious infections, while lincosamides such as clindamycin or cotrimoxazole may be used for less severe infections 2.
• Newer antibiotics such as linezolid and quinupristin/dalfopristin have shown efficacy against MRSA, but are typically reserved for patients who fail or are intolerant of conventional therapy 2, 3, 4.
• The effectiveness and safety of linezolid compared to vancomycin, teicoplanin, or daptomycin for the treatment of MRSA bacteremia have been evaluated in several studies, with results suggesting that linezolid could be a potential first-line treatment option 3, 5, 4.

Treatment Options for MRSA Infections

• Vancomycin and daptomycin are commonly used to treat MRSA bacteremia, but treatment options for persistent or resistant infections may include ceftaroline, combination therapies, or newer antibiotics such as linezolid 3, 5, 4.
• The choice of antibiotic therapy for MRSA infections should be guided by the severity of the infection, the susceptibility of the bacteria, and the patient's clinical condition and medical history 2, 3, 5, 4, 6.