MRSA, or methicillin-resistant staphylococcus aureus, is an infection resistant to methicillin and other antibiotics, such as penicillin. Community acquired MRSA is a skin infection found in people without a recent hospitalization. Signs and symptoms include a red, swollen boil that produces pus and is painful. High risk individuals include those in crowded living conditions such as prisons, sports teams, and dormitories. Treatment involves incision and drainage of the boil and antibiotics for 10 to 14 days.
Clindamycin
Clindamycin is an antibiotic commonly used to treat skin and respiratory infections. Resistance to clindamycin is increasing, limiting its use for community acquired MRSA in certain parts of the world. The treatment dose is 300mg three times a day. Common side effects include nausea, vomiting, diarrhea, and rash. Clindamycin carries a black box warning because of its potential to cause Clostridium difficle associated diarrhea, which requires additional antibiotic treatment.
Doxycycline
Doxycycline is a tetracycline antibiotic commonly used for respiratory and skin infections. Doxycycline is not recommend for pregnant women due to evidence of fetal risk. Children under 8 years old should avoid all tetracyclines because tooth discoloration can occur. The treatment dose is 100mg twice daily. Common side effects include headache, nausea, joint pain, rash, and sensitivity to the sun.
Trimethoprim-Sulfamethoxazole
Trimethoprim-Sulfamethoxazole is a sulfonamide antibiotic used to treat infections of the urinary tract, respiratory system, and skin. Resistance rates are low, making it a reasonable choice for empiric treatment. Pregnant women in the third trimester should avoid trimethoprim-sulfamethoxazole. The treatment dose is one to two double strength tablets daily. Common side effects include rash, nausea, vomiting, diarrhea, and sensitivity to the sun. Avoid trimethoprim-sulfamethoxazole if you are allergic to sulfa drugs.
Rifampin
Rifampin is a medication used commonly to treat tuberculosis, but it can also treat community acquired MRSA. Use rifampin only in combination with another antibiotic because of the high potential for antibiotic resistance. Rifampin can cause significant drug-drug interactions, so check with a pharmacist before taking with other medications. The treatment dose is 600mg once daily. Common side effects include orange or red body fluids, nausea, vomiting, dizziness, and increased liver enzymes. Avoid rifampin if you have underlying liver disease or a history of hepatitis.
Linezolid
Linezolid is an antibiotic commonly used to treat pneumonia and skin infections. Linezolid is expensive and is typically reserved as a last resort to protect its ability to fight resistant infections. An infectious disease expert is commonly consulted prior to its use. The treatment dose is 600mg twice daily. Common side effects include headache, diarrhea, nausea, and increase in blood pressure. Long term use can cause rare, but severe, reactions including a decrease in bone marrow activity, neuropathy, serotonin syndrome, and lactic acidosis.
References
- Centers for Disease Control and Prevention: MRSA
- "Clinical Infectious Diseases"; Practice Guidelines for the Diagnosis and Management of Skin and Soft-Tissue Infections; Dennis L Stevens, et al; November 2005
- "Lancet"; Community-associated meticillin-resistant Staphylococcus aureus; Frank R DeLeo, et al; March 2010
- Epocrates: Clindamycin, Doxycycline, Trmethoprim-Sulfamethoxazole, Rifampin, Linezolid
