Doses - RIFAMPIN

Dogs:

For CNS fungal infections (aspergillosis/histoplasmosis):
a) Rifampin 10 - 20 mg/kg PO tid with amphotericin B and flucytocine. (Schunk 1988)
For actinomycosis:
a) 10 - 20 mg/kg PO q12h PO (Hardie 1984)

Cats:

For CNS fungal infections (aspergillosis/histoplasmosis):
a) Rifampin 10 - 20 mg/kg PO tid with amphotericin B and flucytocine. (Schunk 1988)

Horses:

For treatment of C. equi infections in foals:
a) Rifampin 5 mg/kg PO tid with erythromycin estolate or ethylsuccinate 25 mg/kg PO tid.
May cause urine to become red. Use a continuous course of rifampin as intermittent usemay be associated with allergic reactions. Treat until chest radiographs and plasmafibrinogen levels return to normal. (Hillidge and Zertuche 1987)
For susceptible infections in foals:
a) 5 mg/kg PO q12h (dose extrapolated from adult horses). Used in combination witherythromycin for C. equi infections (see above), but could be used with other agents(e.g., penicillins) to treat other gram positive infections. Should be used with otherantimicrobial agents to minimize the potential for bacterial resistance development.(Caprile and Short 1987)
Monitoring Parameters -
1) Clinical efficacy
a) For monitoring C. equi infections in foals and response to rifampin/erythromycin:
Chest radiographs and plasma fibrinogen levels have been suggested as prognosticindicators when done after 1 week of therapy. (Hillidge and Zertuche 1987)
2) Adverse effects; may consider liver function monitoring with long-term therapy
Client Information - Rifampin may cause urine and other secretions (tears, saliva, etc.) to turnred-orange in color. This is not abnormal.
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products: None

Human-Approved Products:

Rifampin Capsules 150 mg, 300 mg; Rifadin® (Hoechst Marion Roussel); Rimactane® (Ciba);(Rx)
Rifampin Powder for Injection: 600 mg; Rifadin® (Hoechst Marion Roussel) (Rx)