Metronidazole vs Clindamycin CSF penetration

Q: Which of the following drug can cross blood-brain barrier more effectively? (pick one)

A) Metronidazole

B) Clindamycin

Answer: A

Although metronidazole and clindamycin both cover anaerobes, metronidazole penetrates the blood-brain barrier better. The penetration is about 45-50 percent. This makes metronidazole a preferred choice in brain abscesses. Moreover, metronidazole also distributes well into muscle tissues and is a good choice in patients with sepsis or undergoing surgery.

#pharmacology

References:

Warner JF, Perkins RL, Cordero L. Metronidazole therapy of anaerobic bacteremia, meningitis, and brain abscess. Arch Intern Med 1979; 139:167.

Karjagin J, Pähkla R, Karki T, Starkopf J. Distribution of metronidazole in muscle tissue of patients with septic shock and its efficacy against Bacteroides fragilis in vitro. J Antimicrob Chemother 2005; 55:341.

Karjagin J, Pähkla R, Starkopf J. Perioperative penetration of metronidazole into muscle tissue: a microdialysis study. Eur J Clin Pharmacol 2004; 59:809.