Antibiotics
Class Summary
For most complicated cases, 4-6 wk of intravenous penicillin G followed by 6-12 months of oral penicillin V is indicated. For patients with penicillin allergy, clindamycin, ceftriaxone, chloramphenicol, and tetracyclines are good alternatives. Parenteral and oral combinations of these drugs have been successful. Because co-infection with A actinomycetemcomitans is common, covering for this organism when present is important, especially in patients who are critically ill. Actinomycosis is susceptible to third-generation cephalosporins, rifampin, trimethoprim-sulfamethoxazole, ciprofloxacin, tetracyclines, and chloramphenicol.
Penicillin G (Pfizerpen)
First-line drug. Used for IV courses of 4-6 wk. Interferes with synthesis of cell wall mucopeptide during active multiplication, resulting in bactericidal activity against susceptible microorganisms.
Penicillin VK (Beepen-VK, Betapen-VK, Pen-Vee K)
First-line drug to be used as follow-up on previous parenteral therapy.
Clindamycin (Cleocin)
Second-line drug. Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest.
Chloramphenicol (Chloromycetin)
Second-line drug. The PO form is unavailable in the United States. Only use when no other alternatives are available. Binds to 50S bacterial-ribosomal subunits and inhibits bacterial growth by inhibiting protein synthesis.
Ceftriaxone (Rocephin)
Second-line drug. Arrests bacterial growth by binding to one or more penicillin binding proteins.
Tetracycline HCl (Sumycin)
Second-line drug. Inhibits bacterial protein synthesis by binding with 30S and possibly 50S ribosomal subunit(s).
