Antimicrobial agents/therapy rifampin

Many antimicrobial agents have similar pharmacokinetic properties when given orally or parenterally (ie, tetracyclines, trimethoprim-sulfamethoxazole, quinolones, chloramphenicol, metronidazole, clindamycin, rifampin, linezolid and fluconazole). In most cases, oral therapy with these drugs is equally effective, is less costly, and results in fewer complications than parenteral therapy. 

Erythromycin estolate in conjunction with rifampin (both drugs administered orally) can be recommended for the treatment of Rhodococcus equi pneumonia in foals. Early diagnosis of the infection and prompt initiation of therapy considerably increase the effectiveness of treatment. Apart from this specific indication, macrolide antibiotics (including erythromycin) and lincosamides (lincomycin and clindamycin) are contra-indicated in horses. Antimicrobial agents in these classes can cause severe disturbance of the balance between commensal bacterial flora in the colon of the horse. 

Rifampin [RIF am pin], derived from the soil mold Streptomvces. has a broader antimicrobial activity than isoniazid and has found application in the treatment of other bacterial infections. Because resistant strains rapidly emerge during therapy, it is never given as a single agent in the treatment of active tuberculosis. 

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