Sulfadimethoxine (or sulphadimethoxine, trade names Di-Methox or Albon) is a long-lasting sulfonamide antimicrobial medication used in veterinary medicine.

Sulfonamides act as a competitive inhibitor; being structurally similar to PABA, they are able to bind to the enzyme's active site and prevent the synthesis of folic acid from progressing.

[6][3] Sulfadimethoxine can either be given alone (such as under the commercial name Albon) or in combination with ormetoprim to as a "potentiated sulfonamide" to increase antimicrobial activity.

[7][3][6] Its ability to bind to plasma proteins is very high, leading sulfadimethoxine to maintain higher blood levels than most other long-acting sulfonamides.

[8][9][10] Sulfadimethoxine has a relatively high solubility at the pH normally occurring in the kidneys, and is easily reabsorbed into the renal tubules, adding to its long half-life.

[13][14][15] This article incorporates text from the United States National Library of Medicine (ALBON sulfadimethoxine suspension), which is in the public domain.