From the FDA Drug Label
Adults: Parenteral (IM or IV Administration): Serious infections due to aerobic gram-positive cocci and the more susceptible anaerobes (NOT generally including Bacteroides fragilis, Peptococcus species and Clostridium species other than Clostridium perfringens): 600 mg to 1,200 mg per day in 2,3 or 4 equal doses More severe infections, particularly those due to proven or suspected Bacteroides fragilis, Peptococcus species, or Clostridium species other than Clostridium perfringens: 1,200 mg to 2,700 mg per day in 2,3 or 4 equal doses.
The recommended IV dose of clindamycin for severe pharyngitis is 600 mg to 1,200 mg per day in 2,3, or 4 equal doses for serious infections due to aerobic gram-positive cocci. For more severe infections, the dose can be increased to 1,200 mg to 2,700 mg per day in 2,3, or 4 equal doses 1.
From the Research
For severe pharyngitis requiring intravenous clindamycin, the recommended dose is 600-900 mg administered every 8 hours. This dosing is typically used for patients with severe infections who cannot tolerate oral medications or require more rapid achievement of therapeutic drug levels. The duration of IV therapy generally continues until clinical improvement is observed, usually 2-3 days, after which patients can be transitioned to oral clindamycin at a dose of 300-450 mg every 6-8 hours to complete a total 10-day course of treatment. Clindamycin is particularly useful for patients with severe beta-lactam allergies or when there is concern for methicillin-resistant Staphylococcus aureus (MRSA) 2. The medication works by binding to the 50S ribosomal subunit of bacteria, inhibiting protein synthesis. Patients should be monitored for potential side effects including diarrhea, which could indicate Clostridioides difficile infection, a serious potential complication of clindamycin therapy. Adequate hydration should be maintained during IV administration.
Some key points to consider when using clindamycin for severe pharyngitis include:
- The importance of adequate hydration during IV administration
- Monitoring for potential side effects, including diarrhea and signs of Clostridioides difficile infection
- The need to transition to oral clindamycin once clinical improvement is observed, to complete a total 10-day course of treatment
- The usefulness of clindamycin in patients with severe beta-lactam allergies or concern for MRSA
It's also important to note that while clindamycin has been shown to be effective in treating group A streptococcal pharyngotonsillitis, resistance patterns should be considered, and the medication should be used judiciously to minimize the risk of resistance development 3.
In terms of specific dosing, a study from 1992 recommends a dose of 900 mg administered intravenously every 8 hours for serious infections 2. However, the recommended dose range of 600-900 mg every 8 hours is generally considered effective and safe for severe pharyngitis.
Overall, clindamycin can be a useful treatment option for severe pharyngitis, particularly in patients with beta-lactam allergies or concern for MRSA, and should be used in accordance with recommended dosing guidelines and with careful monitoring for potential side effects.