Section 522.2474 - Tolazoline(a)Specifications. Each milliliter of solution contains tolazoline hydrochloride equivalent to 100 milligrams (mg) of base activity.(b)Sponsor. See No. 059399 in § 510.600(c) of this chapter.(c)Conditions of use in horses - (1)Amount. Administer slowly by intravenous injection 4 mg per kilogram of body weight or 1.8 mg per pound (4 milliliters (mL) per 100 kilograms or 4 mL per 220 pounds).(2)Indications for use. For use in horses when it is desirable to reverse the effects of sedation and analgesia caused by xylazine.(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. 79 FR 16197 , Mar. 25, 2014, as amended at 79 FR 74020 , Dec. 15, 2014; 80 FR 13230 , Mar. 13, 2015