Azulfidine

Azulfidine is a brand name for sulfasalazine. Around 90% of each dose reaches the large bowel intact, where gut bacteria split it into two active parts: sulfapyridine, a sulphonamide, and mesalazine, a 5-aminosalicylate. Together they calm inflammation in the bowel lining and modify immune activity elsewhere in the body. Under UK SmPCs for sulfasalazine 500 mg tablets, it is used to bring ulcerative colitis into remission and keep it there, and to treat active Crohn’s disease. The enteric-coated (gastro-resistant) tablets are additionally licensed for rheumatoid arthritis that has not responded to anti-inflammatory painkillers.

This page lists 500 mg tablets in packs of 30, 60, 90, 120, 180, 270 or 360. These are imported generic tablets; the Azulfidine name is not licensed in the UK. Gastro-resistant (enteric-coated) tablets should be swallowed whole, not crushed or broken.

For a moderate or severe attack of ulcerative colitis, adults usually take two to four tablets four times a day, often alongside a steroid, with no more than eight hours between the evening and morning doses. A mild attack is treated with two tablets four times a day. Once remission is reached, the dose is reduced gradually to four tablets daily and continued long term, because stopping, even years later, carries a fourfold higher chance of relapse. Active Crohn’s disease is dosed in the same way. In rheumatoid arthritis, gastro-resistant tablets are started at one a day and increased by one tablet a day each week until a dose of one tablet four times daily or two tablets three times daily is reached, depending on tolerance and response; a clear benefit may take six weeks to appear. Children’s doses are calculated by body weight.

Sulfasalazine is a prescription-only medicine in the UK. Pfizer markets it as Salazopyrin tablets, Salazopyrin EN-Tabs gastro-resistant tablets and Salazopyrin suppositories, and generic tablets, gastro-resistant tablets and an oral suspension are also licensed. All have SmPCs on the electronic medicines compendium.

Sulfasalazine must not be given to children under two, to people with porphyria, or to anyone allergic to sulphonamides, salicylates or sulfasalazine itself. Full blood counts and liver tests are taken before starting, every two weeks for the first three months, monthly for the next three and every three months thereafter, and kidney function is checked at the outset. A sore throat, fever, feeling unwell, pallor, unexplained bruising or yellowing of the skin should be reported at once, as these can signal a blood or liver problem. Treatment is stopped at the first sign of a rash, because severe skin reactions can occur, mostly early on. It may cause folate deficiency and, in G6PD deficiency, haemolytic anaemia. Plenty of fluid helps prevent crystals in the urine. Digoxin absorption may fall, the risk of bone marrow suppression increases with azathioprine or mercaptopurine, and blood sugar should be watched in people on diabetes tablets.

Nausea, stomach discomfort, loss of appetite, headache, dizziness, altered taste, insomnia, tinnitus and a fall in white cells are among the more common effects. Skin and body fluids may take on a yellow colour, and some extended-wear soft contact lenses can be permanently stained. In men, sperm counts may fall, usually recovering within two to three months of stopping. Most reactions appear within the first three months. Your doctor or specialist decides whether Azulfidine suits you and at which dose.