This shared care guideline sets out details for the sharing of care of patients
with rheumatoid arthritis prescribed sulfasalazine. These guidelines provide
additional limited information necessary to aid in the treatment of
rheumatology patients. As with all shared care guidelines these highlight
significant prescribing issues but should be used in conjunction with the
summary of product characteristics (Data sheet) and do not replace the drug
company information .
Indications for the purposes of this guideline; Management of adults with
inflammatory joint disease.

Sulfasalazine usually takes 3-4 months to show an effect.

Dosage

Week 1 – 500mg each evening

Week 2 – 500mg twice daily

Week 3 – 500mg in the morning and 1gram evening

Week 4 – 1 gram twice daily

The dose may be increased to 3 grams if no response (after 3 months).

Tablets should not be crushed or broken. It is recommended that the tablets
should be taken with water.

Contraindications

* Children under 2 years of age (N.B. Use in children over 2 years of age is
outside the scope of this guideline)
* Patients with significant hypersensitivity to sulphonamides or salicylates
* Patients with a history of acute intermittent porphyria

Precautions

* Hepatic disease
* Glucose-6-Phosphate dehydrogenase deficiency
* Diabetes, there is the possibility of interference with blood glucose
regulation
* Previous significant hepatic drug reactions may mean increase of side
effects due to sulfapyridine metabolite.
* Pregnancy - Sulfasalazine has been given safely during pregnancy.
However, all drugs can potentially affect the unborn child. Men and women of
childbearing potential are advised therefore to use a reliable method of
contraception during and for three months after treatment. When planning a
pregnancy it is important that both men and women on this drug discuss
medication with the Rheumatology Team. This should be at least six months
before conception.
* Breastfeeding is acceptable with the small amounts of sulfasalazine that
are secreted.


Monitoring

Prior to starting therapy:

Measure baseline CBC, LFTs and renal function

Ongoing Monitoring:

* CBC and LFT’s fortnightly for the first three months then 3 monthly
thereafter.
* In order to monitor disease activity 3 monthly CRP would be helpful.

Stop and refer to the rheumatology team if:

* Rash.
* Liver enzymes especially transaminase increased x 3 upper limit of normal.
* WCC falls on 3 successive occasions and/or WCC falls below 3.5 x 109
* Platelet count falls on 3 successive occasions
* Platelet count falls below 150 x 109


Side effects

75% of all side effects are seen within 3 months of starting sulfasalazine and
90% are identified within 6 months.

Patients must report mouth ulcers, sore throat, fever, epistaxis, purpura,
unexpected bruising or bleeding, and any unexplained illness/infection and
should be seen urgently for full blood count and liver function tests.

Very common/Common:

* Discolouration of urine and other secretions
* Certain types of extended wear contacts lenses may be permanently stained
during therapy
* Nausea, vomiting, rash, headache, raised temperature and loss of appetite
in approximately 15% (try reducing dose).
* Diarrhoea, abdominal pain, exacerbation of symptoms of colitis, headache,
hypersensitivity reactions (including rash and urticaria)

Uncommon:

* Bone marrow suppression and hepatitis are rare but monitoring mandatory
at onset of treatment.
* Oligospermia (reversible).
* Rarely:
* Acute pancreatitis
* Lung disorders
* Vertigo, tinnitus, peripheral neuropathy, aseptic meningitis, ataxia,
convulsions, insomnia, mental depression and hallucinations
* Renal dysfunction
* Skin reactions (including lupus erythematosus-like syndrome,
Stevens-Johnson syndrome), photosensitization, and alopecia.

Common/Significant Drug Interactions

* Absorption of digoxin and folate may be reduced
* Ampicillin and Rifamipicin may alter sulfasalazine levels
* Toxicity increased when Azathioprine or Mercaptopurine are co-prescribed.
* Warfarin levels may be affected on starting Sulfasalazine
* Antacids may decrease the absorption of sulfasalazine

References

Summary of Product Characteristics: Salazopyrin-EN January 2006
http://emc.medicines.org.uk/.

British Society of Rheumatologists Guidelines July 2000. http://www.rheumatology.org.uk

BNF 50

Stockley’s Drug Interactions 7th Ed

Date of Issue Nov 2006

Reviewed 10/09