---
kind: "section"
citation: "21 C.F.R. § 558.364"
title: "21"
number: "558.364"
heading: "Narasin and nicarbazin."
url: "https://uscodex.org/cfr/21/558.364"
---

# §558.364. Narasin and nicarbazin.

- (a) **Specifications.** A fixed-ratio, combination drug Type A medicated article containing 36 grams narasin and 36 grams nicarbazin per pound.
- (b) **Sponsor.** See No. 058198 in [§ 510.600(c)](/cfr/21/510.600.md?p=c) of this chapter.
- (c) **Tolerances.** See §§ [556.428](/cfr/21/556.428.md) and [556.445](/cfr/21/556.445.md) of this chapter.
- (d) **Conditions of use.** It is used as follows:
  - (1) **Chickens—**
  - (2) Narasin and nicarbazin fixed-ratio, combination drug Type A medicated articles may also be used in combination with:
    - (i) Avilamycin as in [§ 558.68](/cfr/21/558.68.md).
    - (ii) Virginiamycin as in [§ 558.635](/cfr/21/558.635.md).

## Notes

### Amendments

[83 FR 64742, Dec. 18, 2018, as amended at 84 FR 8981, Mar. 13, 2019; 88 FR 14907, Mar. 10, 2023; 88 FR 16550, Mar. 20, 2023]

### Authority

Authority: 21 U.S.C. 354, 360b, 360ccc, 360ccc-1, 371.

### Source

Source: 40 FR 13959, Mar. 27, 1975, unless otherwise noted.

### Amendments

[83 FR 64742, Dec. 18, 2018, as amended at 84 FR 8981, Mar. 13, 2019; 88 FR 14907, Mar. 10, 2023; 88 FR 16550, Mar. 20, 2023]