StacksVerified U.S. regulatory reference

21 CFR §520.2215

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)Specifications. Each milliliter (mL) of suspension contains 250 milligrams (mg) sulfadiazine (as the sodium salt) and 12.5 mg pyrimethamine.
  2. (b)Sponsor. See No. 055246 in § 510.600(c) of this chapter.
  3. (c)Conditions of use in horses—(1) Amount. Administer orally 20 mg sulfadiazine per kilogram (kg) body weight and 1 mg/kg pyrimethamine daily.
    1. (2)Indications for use. For the treatment of equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona.
    2. (3)Limitations. Do not use in horses intended for human consumption. Federal law restricts this drug to use by or on the order of a licensed veterinarian.