From the Guidelines
For cellulitis, oral antibiotics such as cephalexin, penicillin, or clindamycin are recommended as first-line treatment. The choice of antibiotic depends on the severity of the infection and the presence of certain risk factors, such as MRSA infection or nasal colonization with MRSA 1.
Key Considerations
- For patients without risk factors for MRSA, cephalexin 500 mg four times daily, penicillin, or clindamycin 300-450 mg three times daily for 5-7 days is a suitable treatment option 1.
- For patients with suspected MRSA, consider adding another antimicrobial effective against both MRSA and streptococci, such as trimethoprim-sulfamethoxazole (TMP-SMX) or doxycycline 1.
- Treatment duration may be extended to 10-14 days for more severe cases or those with slow response, but a recent guideline recommends a course of 5 to 7 days 1.
Important Notes
- Patients should be monitored for signs of worsening infection, such as spreading redness, increasing pain, fever, or streaking, which may indicate the need for intravenous antibiotics 1.
- Elevation of the affected area, rest, and monitoring for adverse effects are also crucial components of treatment 1.
- The most recent guidelines, including the 2019 National Institute for Health and Care Excellence (NICE) guideline, support the use of shorter courses of antibiotics, such as 5-7 days, for uncomplicated cellulitis 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION The penicillinase-resistant penicillins are available for oral administration and for intramuscular and intravenous injection. The sodium salts of cloxacillin, dicloxacillin, oxacillin, and nafcillin are available for oral use Amoxicillin/clavulanic acid has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section Gram-positive bacteria Staphylococcus aureus Gram-negative bacteria Enterobacter species Escherichia coli Haemophilus influenzae Klebsiella species Moraxella catarrhalis
The oral antibiotics for cellulitis are:
- Dicloxacillin
- Amoxicillin-clavulanate These antibiotics are effective against a range of bacteria, including Staphylococcus aureus and Gram-negative bacteria 2 3.
From the Research
Oral Antibiotics for Cellulitis
- The following oral antibiotics are used to treat cellulitis:
- Penicillin
- Amoxicillin
- Cephalexin 4
- These antibiotics are targeted to cover β-hemolytic streptococci or methicillin-sensitive Staphylococcus aureus, which are the majority of causes of non-purulent, uncomplicated cases of cellulitis 4, 5
- A study comparing a short-course (5 days) and standard (10 days) treatment for uncomplicated cellulitis found that 5 days of therapy with levofloxacin was as effective as 10 days of therapy 6
- Another study found that the optimal time to clinical reassessment is between 2 and 4 days, but this must be interpreted with caution due to considerable heterogeneity and small number of included studies 7
- A review of current practice guidelines suggests that coverage for non-purulent cellulitis is generally not recommended for community-acquired methicillin-resistant Staphylococcus aureus 4, 5
- Data extracted from a multi-center clinical trial found that patients given only oral therapy were more likely to have improved at day 5 compared with those given at least a single dose of intravenous therapy, and were as likely to be back to their normal activities at day 10 and day 30 8