DMARDS

Question 1

indications methotrexate

Answer 1

Rheumatoid arthritis
 Malignant disease – used as an anti-metabolite in cancer therapy
 Crohn’s disease

Question 2

dosing methotrexate

Answer 2

Rheumatology: dose range 5-25mg once weekly

Gastroenterology: Starting dose – 25mg once weekly for 16 weeks

Maintenance dose – 15mg once weekly
Always prescribe methotrexate in multiples of the 2.5mg tablet strength

Question 3

common adverse effects methotrexate

Answer 3

 Nausea, diarrhoea
 Alopecia
 Stomatitis – stop treatment if this occurs, mucositis

Question 4

important adverse effects methotrexate

Answer 4

 Myelosuppression including leucopenia and neutropenia
 Hepatotoxicity
 Pulmonary fibrosis, interstitial pneumonitis
 Pericarditis, pericardial tamponade

Question 5

contraindications methotrexate

Answer 5

 Caution in ulcerative colitis, peptic ulcer disease and ulcerative stomatitis
 Avoid in pregnancy and breastfeeding, severe hepatic or renal impairment, blood disorders
(severe anaemia, leucopenia or thrombocytopenia), untreated folate deficiency and history
of alcohol abuse/cirrhosis
 Hold methotrexate temporarily if patient is systemically unwell with significant infection
requiring anti-infective intervention

Question 6

interactions methotrexate

Answer 6

Trimethoprim/co-trimoxazole (risk of pancytopenia, do not co-prescribe)

 Clozapine (increased risk of agranulocytosis – avoid concomitant use)

 Acitretin (increased plasma methotrexate concentration, increased risk of hepatotoxicity –
avoid concomitant use)

 Live vaccines (high risk of infection due to immunosuppressive effect of methotrexate)

PPIs

Question 7

NSAIDs and methotrexate?

Answer 7

NSAIDs (may reduce methotrexate excretion but unlikely to cause clinically significant
adverse effects, concomitant use common in rheumatic disease)

increased risk of nephrotoxicity

Patients should be advised to avoid taking NSAIDs unless prescribed by their specialist doctor.

Question 8

Baseline tests methotrexate

Answer 8

Baseline tests should include FBC, U&E, LFT, ESR and CRP.

Selected patients may require
pulmonary function testing and CXR.

Question 9

Drug monitoring methotrexate

Answer 9

FBC, U&E and LFT should be checked every 1-2 weeks until
patient is stabilised and then every 2-3 months thereafter (monthly in rheumatology). ESR and CRP
should be re-checked avery 3 months.

Question 10

what should you ask about at every appt regarding methotrexate SE

Answer 10

Also ask about oral ulceration/sore throat, unexplained rash or unusual bruising at every
consultation.

Question 11

methotrexate and pregnancy, contraception etc.

Answer 11

Explain to female patients that they must not take this medication during pregnancy.

Both men and women should be advised to use reliable contraception throughout treatment and for 3-6 months after stopping methotrexate.

If a patient or their partner does become pregnant while on
methotrexate they should inform their doctor immediately and the medication should be stopped.

Question 12

safety netting prescribing methotrexate

Answer 12

Advise patients that they should immediately report to their doctor any features of blood disorder
(sore throat, bruising, mouth ulcers), liver toxicity (nausea, vomiting, abdominal discomfort, dark
urine) or respiratory effects e.g. shortness of breath.

Question 13

what should you co-prescribe with methotrexate?

Answer 13

When starting a patient on methotrexate you should also prescribe folic acid at a dose of 5mg to be
taken once weekly, 1-2 days after the methotrexate dose.

Question 14

methotrexate and pleural effusion?

Answer 14

Patients with significant pleural effusion should have this drained prior to starting methotrexate
because the drug may accumulate in this fluid and cause myelosuppression on returning to the
circulation.

Question 15

what drugs are in the class ‘aminosalycylates’

Answer 15

mesalazine
sulfasalazine
olsalazine
balsalazide

Question 16

MoA aminosalycylates?

Answer 16

Cyclooxygenase enxymes in the colon

Inhibitor

Inhibit mucosal production of arachidonic acid metabolites such as prostaglandins

Question 17

Indications aminosalycylates?

Answer 17

• sulfasalazine RA
• mesalazine UC

Question 18

common adverse effects aminosalycylates?

Answer 18

GI upset (diarrhoea, nausea, vomiting, abdominal pain)

Question 19

Important adverse effects aminosalycylates?

Answer 19

Acute pancreatitis;
Blood disorders including agranulocytosis;
Lupus erythematosus-like syndrome
(sulfasalazine);
Renal dysfunction – interstitial nephritis, nephrotic syndrome not to be used in
moderate or severe renal impairment.

Question 20

cautions and contraindications of aminosalycylates

Answer 20

Caution in the elderly, pregnancy and breastfeeding, patients with a history of asthma and
those with hepatic or renal impairment (avoid if severe)
 Caution with SULFASALAZINE in patients with G6PD deficiency – observe closely for signs of
haemolytic anaemia
 Avoid in patients with known salicylate or sulphonamide hypersensitivity
 Stop aminosalicylate if it is suspected that the patient has developed a blood dyscrasia

Question 21

interactions aminosalycylates

Answer 21

Lactulose – co-prescription will reduce 5-ASA efficacy
 Azathioprine (increased risk of leucopenia)
 Mercaptopurine (increased risk of leucopenia)
 Digoxin – absorption of digoxin may be reduced, review dosage requirement after
introductin of aminosalicylate

Question 22

drug monitoring aminosalycylates

Answer 22

Baseline FBC, LFTs, ESR, CRP should be checked monthly for the first 3 months then 3
monthly thereafter. Re-check blood count immediately if blood dyscrasia suspected. Also check
renal function (U+E) before starting an oral aminosalicylate, at 3 months of treatment and annually
thereafter (more frequently in renal impairment).

Question 23

what should you ask everyone at every consultation about if on aminosalycylates

Answer 23

Patients should be asked about oral ulceration/sore throat, unexplained rash or unusual bruising at
every consultation.

Question 24

indications azathioprine

Answer 24

inflammaotry bowel disease

other things autoimmune and RA and rej of prophylaxis in organ transplantation

Question 25

common adverse effects azathioprine

Answer 25

nausea

Question 26

important adverse effects azathioprine

Answer 26

 Cancer risk – azathioprine increases the risk of lymphoma and skin malignancies
 Bone marrow suppression – anaemia, leucopenia, thrombocytopenia
 Hypersensitivity reactions including interstitial nephritis – discontinue immediately
 Pancreatitis

Question 27

contraindications of azathioprine

Answer 27

 Caution in hepatic and renal impairment
 Avoid in patients with known hypersensitivity to mercaptopurine, those with thiopurine
methyltransferase (TPMT) deficiency and in breastfeeding women

Question 28

interactions azathioprine

Answer 28

 Allopurinol (risk of severe myelosuppression – do not co-prescribe)
 Warfarin (reduced anticoagulant effect) – may need to increase warfarin dose
 Aminosalicylates (bone marrow toxicity – may require increased monitoring
 Trimethoprim/co-trimoxazole (risk of blood disorders)

Question 29

drug monitoring azathioprine

Answer 29

Baseline tests should include FBC, LFT, U&E, ESR and CRP (may also wish to measure
Thiopurine methyltransferase (TPMT)) level prior to starting – at discretion of initiating specialist).

FBC and LFT should be re-checked weekly for the first 8 weeks or until stable, then monthly
thereafter. ESR and CRP should be re-checked every 3 months.

Question 30

what should you ask about at every consultation - DMARDS

Answer 30

Also ask about oral ulceration/sore throat, unexplained rash or unusual bruising at every
consultation.

Question 31

patient communication azathioprine

Answer 31

Explain to patients that this medication increases their risk of skin cancer and it is important that
they take appropriate precautions – avoid excessive sun exposure, use high factor sunscreen.

Explain to female patients that if they become pregnant or are planning to become pregnant they
should continue to take their medication as normal but should notify their doctor as soon as
possible. Both men and women should be advised to use reliable contraception throughout
treatment.

Advise patients that they should take this medication with or after food.

Question 32

when should you hold methotrexate

Answer 32

 Hold methotrexate temporarily if patient is systemically unwell with significant infection
requiring anti-infective intervention