Sulfasalazine, sold under the brand name Azulfidine among others, is a medication used to treat rheumatoid arthritis, ulcerative colitis, and Crohn's disease. It is considered by some to be a first-line treatment in rheumatoid arthritis. It is taken by mouth or can be administered rectally.
Sulfasalazine was approved for medical use in the United States in 1950. It is on the World Health Organization's List of Essential Medicines. Sulfasalazine is available as a generic medication. In 2020, it was the 284th most commonly prescribed medication in the United States, with more than 1million prescriptions.
Sulfasalazine metabolizes to sulfapyridine. Serum levels should be monitored every three months, and more frequently at the outset. Serum levels above 50 μg/L are associated with side effects. In rare cases, sulfasalazine can cause severe depression in young males. It can also cause oligospermia and temporary infertility. Immune thrombocytopenia has been reported.
Sulfasalazine can cause kidney stones.
Sulfasalazine may cause stomach upset, nausea, vomiting, loss of appetite, headache, dizziness, or unusual tiredness. Skin and urine can become orange, with occasional allergic reactions.
Around 90% of a dose of sulfasalazine reaches the colon, where most of it is metabolized by bacteria into sulfapyridine and mesalazine (also known as 5-aminosalicylic acid or 5-ASA). Both metabolites are active; most of the sulfapyridine is absorbed and then further metabolized, but most mesalazine is not, and remains in the colon.
A mix of unchanged, hydroxylated, and glucuronidated sulfapyridine is eliminated in urine, as is acetylated mesalazine and unmetabolized sulfasalazine.
In people with rheumatoid arthritis, the cost-effectiveness of sulfasalazine is improved by combining it with other drugs. It is commonly used in treating inflammatory bowel disease in part due to its cost effectiveness.
1234Vallerand AH, Sanoski CA, Deglin JH (5 June 2014). Davis's drug guide for nurses (Fourteenthed.). Philadelphia. ISBN978-0-8036-4085-6. OCLC881473728.{{cite book}}: CS1 maint: location missing publisher (link)
1234567891011"Sulfasalazine". The American Society of Health-System Pharmacists. Archived from the original on 21 December 2016. Retrieved 8 December 2016.
↑Hamilton R (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p.464. ISBN978-1-284-05756-0.
↑World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.