Drug treatment in rheumatology

Question 1

What are DMARDs mainly used to treat?

Answer 1

Rheumatoid arthritis
SLE
Psoriatic arthritis
Vasculitis

Question 2

What are the 3 most commonly used DMARDs for inflammatory arthritis?/

Answer 2

Methotrexate
Hydroxychoroquine
Sulfasalazine

Question 3

What DMARDs are teratogenic + should be avoided in pregnancy + breast feeding?

Answer 3

Methotrexate
Leflunomide
Cyclophosphamide

Question 4

How long should women avoid pregnancy for after treatment of methotrexate has been stopped?

Answer 4

6 months

Question 5

What should be co-prescribed with methotrexate?

Answer 5

once weekly folic acid than more than 24 hours after methotrexate dose

Question 6

What is the mechanism of action of methotrexate?

Answer 6

• competitively + reversibly inhibits dihydrofolate reductase
• inhibits dihydrofolate > tetrahydrofolate needed in purine + pyrimidine synthesis
• inhibits DNA, RNA + protein synthesis

Question 7

What are the adverse effects of methotrexate?

Answer 7

• nausea
• mouth ulcers + mucositis
• teratogenic
• bone marrow suppression
• hepatitis + cirrhosis
• leukopenia

Question 8

Treatment of methotrexate toxicity

Answer 8

folinic acid

Question 9

What is the mechanism of action of hydroxychloroquine?

Answer 9

Suppresses the immune system by:
- interfering with toll-like receptors
- disrupting antigen presentation
- increased pH in lysosome of immune cells

Question 10

What are the adverse effects of hydroxychloroquine?

Answer 10

• GI disturbances
• retinal toxicity
• hair lightening
• blue/grey skin pigmentation

Question 11

What is the mechanism of action of leflunomide?

Answer 11

Suppresses the immune system by interfering with the production of pyrimidine

Question 12

What are the adverse effects of leflunomide?

Answer 12

• GI upset
• hypertension
• hepatitis
• bone marrow suppression
• teratogenic
• mouth ulcers

Question 13

What is the mechanism of action of sulfasalazine?

Answer 13

5-aminosalicylic acid donor in RA > immunosuppresion + anti inflammatory effect

Question 14

What are the adverse effects of sulfasalazine?

Answer 14

• GI upset
• rash
• hepatitis
• orange urine
• bone marrow suppression
• reversible male infertility

Question 15

What are biological drugs?

Answer 15

Drugs that are designed to impact on the immune system
Mainly monoclonal antibodies

Question 16

Types of biological drugs + example

Answer 16

• TNF-a inhibitors - etanercept + infliximab
• CD-20 inhibitor - rituximab
• IL-6 inhibitors - tocilizumab
• IL-17 antagonists
• JAK inhibitors upadacitnib

Question 17

What are adverse effects for biological drugs?

Answer 17

• immunosuppression > risk of infection
• reactivation of hep B + TP risk

Question 18

If a patient is allergic to sulfasalazine, what drug may they also be allergic to?

Answer 18

aspirin

Question 19

what class of drug is azathioprine?

Answer 19

anti-proliferative immunosuppressant

Question 20

mechanism of action of azathioprine

Answer 20

inhibiton of synthesis of purines needed for DNA + RNA transcription

Question 21

Adverse drug reactions of azathioprine

Answer 21

• N+V
  immunosuppression:
• risk of malignancy
• bone marrow suppression
• infection risk
• hepatitis
• pancreatitis

Question 22

What should be tested before starting azathioprine + why?

Answer 22

TPMT activity
- involved in metabolism of azathioprine
- TPMT gene is high polymorphic
- low TPMT level increases risk of myelosuppresion

Question 23

Drug treatment of rheumatoid arthritis

Answer 23

• first line: monotherapy DMARD e.g. methotrexate + short bridging oral prednisolone
• second line: combination DMARD e.g. sulfasalazine, lefunomide
• IM methyprednisolone for flares

Question 24

Drug treatment of rheumatoid arthritis flare

Answer 24

IM methyprednisolone

Question 25

Drug treatment of systemic lupus erythematous

Answer 25

***hydroxchloroquine*** (+NSAIDs + steroids) severe - DMARDS

Question 26

Drug treatment of discoid lupus erythematosus

Answer 26

topical steroid cream hydroxychloroquine

Question 27

Drug treatment of ankylosing spondylitis

Answer 27

- first line: **NSAIDs** - second line: anti TNF *e.g. etanercept* or mab against IL-17

Question 28

Drug treatment of psoriatic arthritis

Answer 28

first line: **steroids** second line: DMARDs *e.g. methotrexate*

Question 29

Drug treatment of gout + pseudogout

Answer 29

- first line: **NSAIDs + PPI cover** - second line: colchicine - oral steroids *e.g. prednisolone*

Question 30

gout prophylaxis

Answer 30

xanthine oxidase inhibitors *e.g. allopurinol*

Question 31

Drug treatment of septic arthritis

Answer 31

*flucloxacillin* for 4-6 weeks IV initially, then oral

Question 32

Drug treatment of Raynaud's phenomenon

Answer 32

CCBs *e.g. nifedipine*

Question 33

Drug treatment of giant cell arteritis

Answer 33

- if no visual disturbance: **oral prednisolone** - if visual disturbance: **IV methylprednisolone**

Question 34

Drug treatment of polymyalgia rheumatica

Answer 34

oral prednisolone OD

Question 35

Drug treatment of systemic sclerosis

Answer 35

pilocarpine

Question 36

Drug treatment of dermatomyositis + polymyositis

Answer 36

- first line: **high dose corticosteroid** - long term: *methotrexate or azathioprine*

Question 37

Drug treatment of vasculitis

Answer 37

- first line: **corticosteroids** - second line: biologics or DMARDs

Question 38

Mechanism of action of rituximab

Answer 38

Targets CD20 antigen in B cells > destruction