Sulfasalazine

Absorption

Following oral administration of 1 g of sulfasalazine to 9 healthy males, less than 15% of a dose of sulfasalazine is absorbed as the parent drug. Detectable serum concentrations of sulfasalazine have been found in healthy subjects within 90 minutes after ingestion. Maximum concentrations of sulfasalazine occur between 3 and 12 hours post-ingestion, with the mean peak concentration (6 μg/mL) occurring at 6 hours.

Toxicity

Two-year oral carcinogenicity studies were conducted in male and female F344/N rats and B6C3F1 mice. Sulfasalazine was tested at 84 (496 mg/m2), 168 (991 mg/m2), and 337.5 (1991 mg/m2) mg/kg/day doses in rats. A statistically significant increase in the incidence of urinary bladder transitional cell papillomas was observed in male rats. In female rats, two (4%) of the 337.5 mg/kg rats had transitional cell papilloma of the kidney. The increased incidence of neoplasms in the urinary bladder and kidney of rats was also associated with an increase in renal calculi formation and hyperplasia of transitional cell epithelium. For the mouse study, sulfasalazine was tested at 675 (2025 mg/m2), 1350 (4050 mg/m2), and 2700 (8100 mg/m2) mg/kg/day. The incidence of hepatocellular adenoma or carcinoma in male and female mice was significantly greater than the control at all doses tested.
Sulfasalazine did not show mutagenicity in the bacterial reverse mutation assay (Ames test) and in L51784 mouse lymphoma cell assay at the HGPRT gene. However, sulfasalazine showed an equivocal mutagenic response in the micronucleus assay of mouse and rat bone marrow and mouse peripheral RBC and in the sister chromatid exchange, chromosomal aberration, and micronucleus assays in lymphocytes obtained from humans.
Impairment of male fertility was observed in reproductive studies performed in rats at a dose of 800 mg/kg/day (4800 mg/m2). Oligospermia and infertility have been described in men treated with sulfasalazine. Withdrawal of the drug appears to reverse these effects.
There are no adequate and well-controlled studies of sulfasalazine in pregnant women. Reproduction studies have been performed in rats and rabbits at doses up to 6 times the human maintenance dose of 2 g/day based on body surface area and have revealed no evidence of impaired female fertility or harm to the fetus due to sulfasalazine. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.
There have been case reports of neural tube defects (NTDs) in infants born to mothers who were exposed to sulfasalazine during pregnancy, but the role of sulfasalazine in these defects has not been established. However, oral sulfasalazine inhibits the absorption and metabolism of folic acid which may interfere with folic acid supplementation (see Drug Interactions) and diminish the effect of periconceptional folic acid supplementation that has been shown to decrease the risk of NTDs.
A national survey evaluated the outcome of pregnancies associated with inflammatory bowel disease (IBD). In a group of 186 women treated with sulfasalazine alone or sulfasalazine and concomitant steroid therapy, the incidence of fetal morbidity and mortality was comparable to that for 245 untreated IBD pregnancies as well as to pregnancies in the general population. A study of 1,455 pregnancies associated with exposure to sulfonamides indicated that this group of drugs, including sulfasalazine, did not appear to be associated with fetal malformation. A review of the medical literature covering 1,155 pregnancies in women with ulcerative colitis suggested that the outcome was similar to that expected in the general population.
No clinical studies have been performed to evaluate the effect of sulfasalazine on the growth development and functional maturation of children whose mothers received the drug during pregnancy.

Description

Sulfasalazine (brand name Azulfidine in the U.S., Salazopyrin and Sulazine in Europe and Hong Kong) was developed in the 1950s specifically to treat rheumatoid arthritis. It was believed at the time that bacterial infections were the cause of rheumatoid arthritis. Sulfasalazine is a sulfa drug, (a derivative of mesalazine) and is formed by combining sulfa pyridine and salicylate with an azo bond. It may be abbreviated SSZ.

Description

Sulfasalazine is used primarily as an anti-inflammatory agent in the treatment of inflammatory bowel disease as well as for rheumatoid arthritis. It is not a pain killer.

Chemical properties

Brownish-Yellow Crystals

The Uses of Sulfasalazine

Sulfasalazine is an anti-inflammatory (gastrointestinal). Sulfasalazine has been used in granulomatous colitis.

The Uses of Sulfasalazine

Anti-inflammatory (gastrointestinal). Has been used in granulomatous colitis.

The Uses of Sulfasalazine

anticolitis and Crohn's disease

The Uses of Sulfasalazine

Sulfasalazine is a prodrug of the anti-inflammatory agent 5-aminosalicylic acid that is covalently linked to the antibiotic sulfapyridine by an azo bond. This bond is rapidly cleaved by bacteria in the terminal ileum and colon, thus releasing the active anti-inflammatory component. It has long been used in treatment of inflammatory bowel disease and rheumatoid arthritis because of its ability to induce T lymphocyte apoptosis, modulate inflammatory mediators from both cyclooxygenase/5-lipoxygenase pathways and NF-κB signaling pathways, attenuate transcription of proinflammatory cytokines, and activate PPARγ.[Cayman Chemical]

The Uses of Sulfasalazine

An inhibitor of of GSH-H-transferase and NF-kB activation and an apoptosis inducer

Indications

In the US, sulfasalazine is indicated to treat mild to moderate ulcerative colitis and to prolong the remission period between acute attacks of ulcerative colitis. Sulfasalazine is also indicated as an adjunct therapy in severe ulcerative colitis.For the delayed-release tablet formulation, sulfasalazine is also indicated to treat rheumatoid arthritis in pediatric patients who have responded inadequately to salicylates or other nonsteroidal anti-inflammatory drugs or polyarticular-course juvenile rheumatoid arthritis with the same patients' characteristics.

Background

Sulfasalazine is an anti-inflammatory drug structurally related to salicylates and other non-steroidal anti-inflammatory drugs. It is indicated for managing inflammatory diseases such as ulcerative colitis and rheumatoid arthritis (RA). Metabolized by intestinal bacteria, sulfasalazine is broken down into mesalazine and sulfapyridine, 2 compounds that carry out the main pharmacological activity of sulfasalazine.
Sulfasalazine was first used in 1940 for rheumatic polyarthritis, and has been firmly established itself as one fo the most useful disease-modifying antirheumatic drug (DMARD). Compared to the first line treatment of RA like methotrexate, sulfasalazine is almost as efficacious as methotrexate although with slightly less tolerability. However, sulfasalazine has less teratogenic side effects and faster onset of action compared to conventional DMARD. Sulfasalazine fell out of favor as the drug of choice for RA due to poorly designed clinical trials in 1950 but regained interest from the clinical community in the late 1970.
Although sulfasalazine is only approved by the FDA for ulcerative colitis, research have shown that sulfasalazine is also beneficial for patients with Crohn's disease. Meta-analysis of 19 randomized controlled trials indicated that sulfasalazine is superior to placebo in inducing remission; however, with no supported evidence of mucosal healing, sulfasalazine is not FDA-recommmended for treatment of Crohn's disease.

What are the applications of Application

Sulfasalazine is an inhibitor of of GSH-H-transferase and NF-kB activation and an apoptosis inducer

Definition

ChEBI: An azobenzene consisting of diphenyldiazene having a carboxy substituent at the 4-position, a hydroxy substituent at the 3-position and a 2-pyridylaminosulphonyl substituent at the 4'-position.

Indications

Sulfasalazine is used in the treatment of inflammatory bowel disease, including ulcerative colitis and Crohn's disease. It is also indicated for use in rheumatoid arthritis and used in other types of inflammatory arthritis (e.g. psoriatic arthritis) where it has a beneficial effect. It is often well tolerated compared to other DMARDS.
In clinical trials for the treatment of chronic alcoholics, sulfasalazine has been found to reverse the scarring associated with cirrhosis of the liver .
Cells called myofibroblasts, which contribute to scar tissue in a diseased liver, also appear to secrete proteins that prevent the breakdown of the scar tissue. Sulfasalazine appears to retard this secretion.

Indications

Sulfasalazine (Azulfidine) is approved for the treatment of rheumatoid arthritis and ulcerative colitis. It is also used to treat ankylosing spondylitis and Crohn’s disease. Comparisons of sulfasalazine with other DMARDs suggest that it is more effective than hydroxychloroquine, azathioprine, and oral gold compounds. It is at least as effective as intramuscular gold and penicillamine. It has a greater degree of toxicity than hydroxychloroquine but less than gold compounds and penicillamine. After 5 years, approximately 75% of patients have discontinued sulfasalazine therapy, primarily because of a lack of efficacy as opposed to intolerable side effects.

Indications

Sulfasalazine (Azulfidine) was first introduced in 1940 as a treatment for rheumatoid arthritis. It was found that a number of patients with coexistent inflammatory bowel disease showed improvement of their GI symptoms, and the drug has subsequently been used for the treatment of patients with inflammatory bowel disease.

General Description

Odorless yellow or brownish-yellow to orange powder. Tasteless.

General Description

Sulfasalazine (Azufidine) is an azo prodrug that is reducedby the bacterium present in the lower intestine to its activemetabolites, sulfapyridine and 5-aminosalicylic acid (5-ASA or mesalamine). It has been used for the treatment ofRA or ankylosing spondylitis, and inflammatory bowel diseases(IBDs) such as ulcerative colitis and Crohn disease.It is generally agreed that the therapeutic effects of sulfasalazinein treating IBDs are due mainly through its activemetabolite, 5-ASA. 5-ASA is believed to work, via similarmechanisms of action to the salicylates discussed earlier, byblocking prostaglandin synthesis in the lower intestine. On the other hand, because 5-ASA is completelyionized and very little of this metabolite can enter into systemiccirculation, the antirheumatic effects of sulfasalazinehave been attributed to its other active metabolite, sulfapyridine. In a more recent study, sulfasalazine and sulfapyridinewere found to inhibit 5-aminoimidazole-4-carboxamideribonucleotide transformylase, an enzyme involved in denovo purine biosynthesis. Sulfasalazine also inhibits neutrophilfunction, reduces immunoglobulin levels, and interfereswith T-cell function via suppression of NF-κB activation. Furthermore, like methotrexate, sulfasalazine hasalso been shown to inhibit osteoclastogenesis, thereby preventingbone erosion in arthritic patients.
It should be pointed out that approximately one third of thepatients treated long term with sulfasalazine discontinued thedrug because of dose-related adverse effects including nausea,dyspepsia, vomiting, headache, rash, gastric distress, especiallyin patients on a daily dosage of greater than 4 g (or aserum sulfapyridine levels above 50 mg/mL).

Air & Water Reactions

Light sensitive and may be sensitive to prolonged exposure to air. Dust can be explosive when suspended in air at specific concentrations. Insoluble in water.

Fire Hazard

Flash point data for Salicylazosulfapyridine are not available; however, Salicylazosulfapyridine is probably combustible.

Pharmaceutical Applications

One of the earliest and most successful sulfonamides to be developed was sulfapyridine, which fell into disuse because of unwanted effects such as crystalluria. Later, a number of salicylazosulfonamides, developed because of their increased water solubility, showed anti-inflammatory properties; one of them, sulfasalazine (salicylazosulfapyridine), has come into general use for ulcerative colitis.
After oral administration, some intact compound is absorbed from the upper gastrointestinal tract, appearing in the blood in 1–2 h, but most is cleaved by colonic bacteria to yield sulfapyridine and 5-aminosalicylic acid (mesalamine, mesalazine). Controlled trials have confirmed the efficacy of 5-aminosalicylic acid alone in ulcerative colitis, the sulfonamide component merely acting as a carrier. Thus, in remarkable extension of the good fortune that attended the discovery of sulfanilamide as the unexpected active principle of Prontosil, a cleavage product appears to be responsible for the beneficial effect of sulfasalazine. Since most of the side effects associated with sulfasalazine are attributable to sulfapyridine, there seems little reason, other than cost, to use it in preference to mesalamine.
Sulfasalazine is also of benefit in Crohn’s disease and rheumatoid arthritis, but the role, if any, of sulfapyridine in the overall effect is unclear.

Mechanism of action

Sulfasalazine is composed of sulfapyridine and 5- ASA molecules linked by an azo bond. Sulfapyridine has no effect on the inflammatory bowel disease, and instillation of this agent into the colon does not heal colonic mucosa.

Pharmacokinetics

The mode of action of sulfasalazine or its metabolites, 5-aminosalicylic acid and sulfapyridine, is still under investigation but may be related to the anti-inflammatory and/or immunomodulatory properties that have been observed in animal and in vitro models, to its affinity for connective tissue, and/or to the relatively high concentration it reaches in serous fluids, the liver, and intestinal walls, as demonstrated in autoradiographic studies in animals. In ulcerative colitis, clinical studies utilizing rectal administration of sulfasalazine, sulfapyridine, and 5-aminosalicylic acid have indicated that the major therapeutic action may reside in the 5-aminosalicylic acid moiety. The relative contribution of the parent drug and the major metabolites in rheumatoid arthritis is unknown.

Pharmacology

Sulfasalazine is a prodrug of which 70% is converted by colon bacteria to two active metabolites, sulfapyridine and 5-aminosalicylic acid (mesalamine). Sulfapyridine has antibacterial activities, and 5-aminosalicylic acid is antiinflammatory; however, these effects do not account for the ability of this drug to slow the processes of rheumatoid arthritis. Recent research suggests additional activities of sulfasalazine that may be relevant to these effects: its ability to increase adenosine levels, its inhibitory effects on IL-1 and TNF- release, and its inhibition of NF-κB.

Pharmacokinetics

sulfasalazine is poorly absorbed, with approximately 20% of the ingested sulfasalazine reaching the systemic circulation. The remainder of the ingested dose is metabolized by colonic bacteria into its components, sulfapyridine and mesalamine (5-ASA). Most of the sulfapyridine metabolized from sulfasalazine (60–80%) is absorbed in the colon following oral administration, and approximately 25% of the 5-ASA metabolized from sulfasalazine is absorbed in the colon.

Clinical Use

Sulfasalazine (2-hydroxy-5[[4-[(2-pyridinylamino)sulfonyl]phenyl]azo]benzoic acid or 5-[p-(2-pyridylsulfamoyl)phenylazo]salicylic acid) is a brownish yellow, odorlesspowder, slightly soluble in alcohol but practically insolublein water, ether, and benzene.
Sulfasalazine is broken down in the body to m-aminosalicylicacid and sulfapyridine. The drug is excreted throughthe kidneys and is detectable colorimetrically in the urine,producing an orange-yellow color when the urine is alkalineand no color when the urine is acid.

Clinical Use

Sulfasalazine (Azulfidine) was first introduced in 1940 as a treatment for rheumatoid arthritis.

Side Effects

Sulfsalazine metabolizes to sulfa pyridine. 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 temporary infertility. Immune thrombocytopenia has been reported.
Sulfasalazine inhibits dihydrofolate reductase, and can cause folate deficiency and megaloblastic anemia.
Sulfasalazine can cause hemolytic anemia in people with G6PD deficiency.

Side Effects

It is, however, responsible for most of sulfasalazine’s side effects, including sulfa allergic reactions. 5-ASA, the active metabolite, may inhibit the synthesis of mediators of inflammation.

Side Effects

Mild to moderate side effects, including nausea, vomiting, abdominal pain, diarrhea, anorexia, and headache, occur in up to 33% of patients taking this drug. Skin rash and discoloration, fever, reversible male infertility, and liver enzyme elevation occur less frequently. Rare hematological abnormalities, such as agranulocytosis, aplastic anemia, hemolytic anemia, neutropenia, or other blood dyscrasias, can be fatal. Hypersensitivity reactions occur rarely.

Synthesis

Sulfasalazine, 5-[p-[(4,6-dimethyl-2-pyridinyl)sulfamoyl]phenylazo]salicylic acid (33.1.22), is a derivative of sulfapyridine drug described above and one of the few sulfanilamides in which the free amino group in the benzene ring is modified, and it is synthesized by an azo-coupling reaction of a diazo salt, which is synthesized by reacting sulfapyridine (33.1.21) with nitrous acid and salicylic acid alkaline media.

Veterinary Drugs and Treatments

Sulfasalazine is used for the treatment of inflammatory bowel disease in dogs and cats. It has also been suggested for adjunctive use in treating vasculitis in dogs.

Drug interactions

Potentially hazardous interactions with other drugs
Ciclosporin: may reduce ciclosporin levels.

Metabolism

In the intestine, sulfasalazine is metabolized by intestinal bacteria to sulfapyridine and 5-aminosalicylic acid. Of the two species, sulfapyridine is relatively well absorbed from the intestine and highly metabolized, while 5-aminosalicylic acid is much less well absorbed.Approximately 15% of a dose of sulfasalazine is absorbed as the parent drug and is metabolized to some extent in the liver to the same two species.Sulfapyridine can also be metabolized to 5-hydroxysulfapyridine and N-acetyl-5-hydroxy sulfapyridine. 5-aminosalicylic acid is primarily metabolized in both the liver and intestine to N-acetyl-5 aminosalicylic acid via a non-acetylation phenotype-dependent route.

Metabolism

After cleavage of the sulfasalazine molecule about 60 to 80% of available sulfapyridine is absorbed, and undergoes extensive metabolism in the liver by acetylation, hydroxylation, and glucuronidation.
Most of a dose of sulfasalazine is excreted in the urine. Unchanged sulfasalazine accounts for 15% of the original dose, sulfapyridine and its metabolites 60%, and 5-ASA and its metabolites 20-33%.

storage

Store at RT

Mode of action

Sulfasalazine, and its metabolite 5-ASA, are poorly absorbed from the gut. Its main mode of action is therefore believed to be inside the intestine.
Bowel disease
In Crohn's disease and ulcerative colitis, it is thought to be an antinflammatory drug that is essentially providing topical relief inside the intestine. It does this via a number of mechanisms such as reducing the synthesis of inflammatory mediators known as eicosanoids and inflammatory cytokines. However, unlike glucocorticoids ( another class of drug used in the treatment in inflammatory bowel disease ), sulfasalazine is a mild immunosuppressant.
Arthritis
When treatment for arthritis is successful, pain, joint swelling and stiffness will be reduced and this may slow down or stop the development of joint damage. The precise reasons why sulfasalazine are effective in various forms of arthritis is not clearly understood. Because sulfasalazine and its metabolite 5-ASA are poorly absorbed into the bloodstream, it is surprising that the drug is effective against symptoms outside of the intestine. One possible explanation is that, given that ulcerative colitis produces arthritic symptoms, the arthritic symptoms are actually a product of unrecognized ulcerative colitis , which is effectively treated with sulfazalazine.

Precautions

Sulfasalazine is contraindicated in individuals with hypersensitivityto salicylates, sulfonamides, sulfonylureas,and certain diuretics (furosemide, thiazides, andcarbonic anhydrase inhibitors). Because it can causekernicterus, sulfasalazine is contraindicated in infantsand children under 2 years of age. Sulfasalazine passesinto breast milk and is therefore contraindicated fornursing mothers. Similarly, pregnant women near termshould not use this drug, although it appears to be thesafest of the DMARDs during early pregnancy.Sulfasalazine can precipitate attacks of porphyria andshould not be used by individuals with bowel or urinaryobstruction.
Sulfasalazine can inhibit the absorption of cardiacglycosides and folic acid. It may displace certain drugs,including warfarin, phenytoin, methotrexate, tolbutamide,chlorpropamide, and oral sulfonylureas, fromtheir protein binding sites. Sulfasalazine can diminishthe effectiveness of penicillins and estrogen-containingoral contraceptives.

References

1) Peppercorn (1984),?Sulfasalazine. Pharmacology, clinical use, toxicity, and related drug development; Ann. Intern. Med.,?101?377 2) Wahl?et al. (1998),?Sulfasalazine: a potent and specific inhibitor of nuclear factor kappa B; J. Clin. Invest.,?101?1163 3) Sheldon?et al. (1988),?Effect of sulphasalazine and its metabolites on mitogen induced transformation of lymphocytes D clues to its clinical action?; Br. J. Rheumatol.,?27?344 4) Fujiwara?et al. (1990),?Inhibition of proliferation responses and interleukin 2 production by salazosulfapyridine and its metabolites; Jpn. J. Pharmacol.,?54?121 5) Chung and Sontheimer (2009),?Sulfasalazine inhibits the growth of primary brain tumors in dependent of nuclear factor-κB; J.Neurochem.,?110?182 6) Patel?et al. (2004),?Differentiation of substrate and non-substrate inhibitors of transport system Xc – :an obligate exchanger of L-glutamate and L-cystine; Neuropharmacol.,?46?273