The drug has low acute per oral toxicity in the absence of hyper-sensitivity. There is no specific antidote and treatment should be supportive.
The tablets are stable for five years.
Sulfasalazine is contraindicated in:
Infants under the age of 2 years.
Patients with a known hypersensitivity to sulfasalazine, its metabolites or any of the excipients as well as sulfonamides or salicylates.
Patients with porphyria.
Certain types of extended wear soft contact lenses may be permanently stained during therapy.
Povidone; maize starch; magnesium stearate; colloidal silicon dioxide; cellulose acetate phthalate; propylene glycol; traces of beeswax, carnauba wax, glyceryl monosterate, talc.
Yellow film-coated, ovoid gastro-resistant tablets embossed “Kph†on one side and “102†on the other.
Overall, about 75% of ADRs occur within 3 months of starting therapy, and over 90% by 6 months. Some undesirable effects are dose-dependent and symptoms can often be alleviated by reduction of the dose.
General
Sulfasalazine is split by intestinal bacteria to sulfapyridine and 5-amino salicylate so ADRs to either sulfonamide or salicylate are possible. Patients with slow acetylator status are more likely to experience ADRs related to sulfapyridine. The most commonly encountered ADRs are nausea, headache, rash, loss of appetite and raised temperature.
Specific
The adverse reactions observed during clinical studies conducted with Sulfasalazine have been provided in a single list below by class and frequency (very common (>1/10); common (>1/100 to< 1/10); uncommon (>1/1000 to < 1/100). Where an adverse reaction was seen at different frequencies in clinical studies, it was assigned to the highest frequency reported.
Additional reactions reported from post-marketing experience are included as frequency Not known (cannot be estimated from the available data) in the list below.
| Body System | Adverse drug reactions |
| Infections and infestations | |
| Not known | Pseudomembranous colitis |
| Blood and Lymphatic System Disorders | |
| Common | Leukopenia |
| Uncommon | Thrombocytopenia* |
| Not known | Agranulocytosis, aplastic anemia, haemolytic anemia, Heinz body anaemia, hypoprothrombinaemia, lymphadenopathy, macrocytosis, megaloblastic anemia, methaemoglobinaemina, neutropenia, pancytopenia |
| Immune System Disorders: | |
| Not known | Anaphylaxis, polyarteritis nodosa, serum sickness |
| Metabolism and Nutrition Disorders: | |
| Not known | Loss of appetite |
| Psychiatric Disorders: | |
| Common | Insomnia |
| Uncommon | Depression |
| Not known | Hallucinations |
| Nervous System Disorders: | |
| Common | Dizziness, headache, taste disorders |
| Uncommon | Convulsions |
| Not known | Aseptic meningitis, ataxia, encephalopathy, peripheral neuropathy, smell disorders |
| Ear and Labyrinth Disorders: | |
| Common | Tinnitus |
| Uncommo | Vertigo |
| Eye Disorders: | |
| Common | Conjuctivial and scleral injection |
| Cardiac Disorders: | |
| Not known | Allergic myocarditis, cyanosis, pericarditis |
| vascular Disorders: | |
| Uncommon | Vasculitis |
| Respiratory, Thoracic and Mediastinal Disorders: | |
| Common | Cough |
| Uncommon | Dyspnoea |
| Not known | Fibrosing alveolitis, eosinophilic infiltration, interstitial lung disease |
| Gastrointestinal Disorders: | |
| Very Common | Gastric distress, nausea |
| Common | Abdominal pain, diarrhoea, vomiting, stomatitis |
| Not known | Aggravation of ulcerative colitis, pancreatitis, parotitis |
| Hepato-biliary Disorders: | |
| Not known | Hepatic failure, fulminant hepatitis, hepatitis* |
| Skin and Subcutaneous Tissue Disorders: | |
| Common | Pruritus |
| Uncommon | Alopecia, urticaria |
| Not known | Epidermal necrolysis (Lyell's syndrome), Stevens-Johnson syndrome, drug rash with eosinophilia and systemic symptoms (DRESS), toxic pustuloderma, erythema, exanthema, exfoliative dermatitis, periorbital oedema, lichen planus, photosensitivity |
| Musculoskeletal and Connective Tissue Disorders: | |
| Common | Arthralgia |
| Not known | Systemic lupus erythematosus |
| Renal and Urinary Disorders: | |
| Common | Proteinuria |
| Not known | Nephrotic syndrome, interstitial nephritis, crystalluria*, haematuria |
| Reproductive System and Breast Disorders: | |
| Not known | Reversible oligospermia* |
| General Disorders and Administration Site Conditions: | |
| Common | Fever |
| Uncommon | Facial oedema |
| Not known | Yellow discoloration of skin and body fluids |
| Investigations: | |
| Uncommon | Elevation of liver enzymes |
| Not known | Induction of autoantibodies |
In two-year carcinogenicity studies in rats and mice, sulfasalazine showed some evidence of carcinogenicity. In rats, there was a small increase in the incidence of transitional cell papillomas in the urinary bladder and kidney. The tumours were judged to be induced mechanically by calculi formed in the urine rather than through a direct genotoxic mechanism. In the mouse study, there was a significant increase in the incidence of hepatocellular adenoma or carcinoma. The mechanism of induction of hepatocellular neoplasia has been investigated and attributed to species-specific effects of sulfasalazine that are not relevant to humans.
Sulfasalazine did not show mutagenicity in the bacterial reverse mutation assay (Ames test) or in the L51784 mouse lymphoma cell assay at the HGPRT gene. It did not induce sister chromatid exchanges or chromosomal aberrations in cultured Chinese hamster ovary cells, and in vivo mouse bone marrow chromosomal aberration tests were negative. However, sulfasalazine showed positive or equivocal mutagenic responses in rat and mouse micronucleus assays, and in human lymphocyte sister chromatid exchange, chromosomal aberration and micronucleus assays. The ability of sulfasalazine to induce chromosome damage has been attributed to perturbation of folic acid levels rather than to a direct genotoxic mechanism.
Based on information from non-clinical studies, sulfasalazine is judged to pose no carcinogenic risk to humans. Sulfasalazine use has not been associated with the development of neoplasia in human epidemiology studies.
a) Induction and maintenance of remission of ulcerative colitis; treatment of active Crohn's Disease.
b) Treatment of rheumatoid arthritis which has failed to respond to non-steroidal anti-inflammatory drugs (NSAIDs).
Pharmacological particulars: around 90% of a dose reaches the colon where bacteria split the drug into sulfapyridine (SP) and mesalazine (ME). These are also active, and the unsplit sulfasalazine (SASP) is also active on a variety of symptoms. Most SP is absorbed, hydroxylated or glucuronidated and a mix of unchanged and metabolised SP appears in the urine. Some ME is taken up and acetylated in the colon wall, such that renal excretion is mainly AC-ME. SASP is excreted unchanged in the bile and urine.
Overall the drug and its metablites exert immunimodulatory effects, antibacterial effects, effects on the arachidonic acid cascade and alteration of activity of certain enzymes. The net result clinically is a reduction in activity of the inflammatory bowel disease. In rheumatoid arthritis a disease modifying effect is evident in 1-3 months, with characteristics falls in CRP and other indicators of inflammation. ME is not believed to be responsible for this effect.
Radiographic studies show marked reduction in progression (larsen or sharp index) compared with placebo or hydroxychloroquine over two years in early patients. If drug is stopped the benefit appears to be maintained.
Pharmacokinetic particulars: studies with en-tabs show no statistically significant differences in main parameters compared with an equivalent dose of SASP powder, and the figures produced below relate to ordinary tablets. With regard to the use of Salazopyrin in bowel disease there is no evidence that systemic levels are of any relevance other than with regard to ADR incidence. Here levels of SP over about 50µg/ml are associated with a substantial risk of ADRS, especially in slow acetylators.
For SASP given as a single 3g oral dose, peak serum levels of SASP occured in 3-5 hours, elimination half life was 5.7±0.7 hours, lag time 1.5 hours. During maintenance therapy renal clearance of SASP was 7.3±1.7ml/min, for SP 9.9±1.9 and AC-ME 100±20. Free SP first appears in plasma in 4.3 hours after a single dose with an absorption half life of 2.7 hours. The elimination half life was calculated as 18 hours.
Turning to mesalazine, in urine only AC-ME (not free ME) was demonstrable, the acetylation probably largely achieved in the colon mucosa. After a 3g SASP dose lag time was 6.1±2.3 hours and plasma levels kept below 2µg/ml total ME. Urinary excretion half life was 6.0±3.1 hours and absorption half life based on these figures 3.0±1.5 hours. Renal clearance constant was 125ml/min corresponding to the GFR.
With regard to rheumatoid arthritis there is no data which suggests any differences from those above.
02/2014
Salazopyrin En-Tabs
Pfizer Limited
Ramsgate Road
Sandwich
Kent CT13 9NJ
United Kingdom
Store in a dry place
Polyolefin Square pot with screw cap. To contain 112 tablets
PL 00057/1041
Sulfasalazine EP 500mg
Complete blood counts, including differential white cell count and liver function tests, should be performed before starting sulfasalazine, and every second week during the first three months of therapy. During the second three months, the same tests should be done once monthly and thereafter once every three months, and as clinically indicated. Assessment of renal function (including urinalysis) should be performed in all patients initially and at least monthly for the first three months of treatment. Thereafter, monitoring should be performed as clinically indicated. The patient should also be counselled to report immediately with any sore throat, fever, malaise, pallor, purpura, jaundice or unexpected non-specific illness during sulfasalazine treatment, this may indicate myelosuppression, haemolysis or hepatoxicity. Treatment should be stopped immediately while awaiting the results of blood tests.
Sulfasalazine should not be given to patients with impaired hepatic or renal function or with blood dyscrasias, unless the potential benefit outweighs the risk.
Sulfasalazine should be given with caution to patients with severe allergy or bronchial asthma.
Use in children with the concomitant condition systemic onset juvenile rheumatoid arthritis may result in a serum sickness like reaction; therefore sulfasalazine is not recommended in these patients.
Since sulfasalazine may cause haemolytic anaemia, it should be used with caution in patients with G-6-PD deficiency.
Oral sulfasalazine inhibits the absorption and metabolism of folic acid and may cause folic acid deficiency , potentially resulting in serious blood disorders (e.g., macrocytosis and pancytopenia), this can be normalised by administration of folic acid or folinic acid (leucovorin).
Because sulfasalazine causes crystalluria and kidney stone formation, adequate fluid intake should be ensured during treatment.
Oligospermia and infertility may occur in men treated with sulfasalazine. Discontinuation of the drug appears to reverse these effects within 2 to 3 months.
No specific effects.
EN-Tablets should be used where there is gastro-intestinal intolerance of plain tablets. They should not be crushed or broken.
The dose is adjusted according to the severity of the disease and the patient's tolerance to the drug, as detailed below.
Elderly Patients: No special precautions are necessary.
a) Ulcerative colitis
Adults
Severe Attack: Salazopyrin 2-4 tablets four times a day may be given in conjunction with steroids as part of an intensive management regime. Rapid passage of the tablets may reduce effect of the drug.
Night-time interval between doses should not exceed 8 hours.
Moderate Attack: 2-4 tablets four times a day may be given in conjunction with steroids.
Mild Attack: 2 tablets four times a day with or without steroids.
Maintenance Therapy: With induction of remission reduce the dose gradually to 4 tablets per day. This dosage should be continued indefinitely, since discontinuance even several years after an acute attack is associated with a four fold increase in risk of relapse.
Children
The dose is reduced in proportion to body weight.
Acute Attack or relapse: 40- 60mg/kg per day
Maintenance Dosage: 20 - 30mg/kg per day
Salazopyrin Suspension may provide a more flexible dosage form.
b) Crohn 's Disease
In active Crohn's Disease, Salazopyrin should be administered as in attacks of ulcerative colitis (see above).
c) Rheumatoid Arthritis
Patients with rheumatoid arthritis, and those treated over a long period with NSAIDs, may have sensitive stomachs and for this reason enteric-coated Salazopyrin (EN-Tabs) are recommended for this disease, as follows:
The patient should start with one tablet daily, increasing his dosage by a tablet a day each week until one tablet four times a day, or two three times a day are reached, according to tolerance and response. Onset of effect is slow and a marked effect may not be seen for six weeks. A reduction in ESR and C-reactive protein should accompany an improvement in joint mobility. NSAIDs may be taken concurrently with Salazopyrin.
Take the tablets whole: Do not break
12th August 2010
