Arthritis pharmacology Flashcards
When would you give an NSAID?
Inflammatory arthritis
mechanical MSK pain
Serositis
What kind of drug is celecoxib?
Cox-2 inhibitors
How do cox-2 inhibitors work?
They inhibit cyclooxygenase-2 which stops the formation of prostaglandins
Give an example of a cox-1 inhibitor
aspirin
Why does taking NSAIDs increase risk of peptic ulcers?
Prostaglandin is inhibited by NSAIDs.
Prostaglandin inhibits HCl secretion in stomach.
No prostaglandins then more HCl in the stomach, leading to peptic ulcers
What can be other adverse effects of NSAIDs?
Wheeze
Rash
Renal impairment
What is the analgesic pathway ?
Non-opioid e.g. aspirin, NSAID, paracetamol,
THEN
Weak opioid e.g. codeine
THEN
Strong opioid e.g. morphine
What is a DMARD?
Disease modifying anti-rheumatic drug
Why use a DMARD?
Reduces inflammation
Reduces the rate of joint damage
What do you need to keep in mind when using DMARDs?
Must have regular blood tests
Within what time period of symptom onset is a DMARD aimed to begin?
Within 3 months
Which DMARDs are used for RA?
Methotrexate
Sulfsalazine
In what other conditions is methotrexate prescribed?
Connective tissue disease
vasculitis
Psoriatic arthritis
What adverse effects must you remember about methotrexate?
Hepatitis- limited alcohol
Mouth ulcers
Leucopenia
N&D
FBCs and LFTs monitored
Methotrexate is teratogenic. What time period must it be stopped before conception?
3 months
What are the adverse effects of sulfsalazine?
Rash
Neutropenia
Hepatitis
oligozoospermia
What is oligozoospermia?
Low sperm count
When is hydroxychloroquine used?
SLE, Sjogrens and RA
Why is it used in these conditions?
Can help to clear skin, joints and general malaise
What other DMARDs can be given?
Sodium aurothiomalate (gold) Penicillamine
What are biologics?
Anti-TNF drugs e.g. infliximab, etanercept
In what conditions can anti-TNFs be given?
RA, AS and psoriatic arthritis
What is the mechanism of anti-TNFs?
???TNF is a cytokine.
What are the adverse effects of anti-TNFs?
TB reactivation
Possible malignancy risk espec. malignant melanoma
When can anti-TNFs be given?
When DMARDs have been unsuccessful
High disease activity score as per DAS28
What treatment would you give for acute gout?
NSAIDs
Colchine if NSAIDs contra-indicated but beware D&V
What treatment would you give for gout prophylaxis?
Allopurinol
Febuxostat
How is prophylactic gout treatment started?
Need cover for 2-4 weeks with NSAID and prophylactic drug since can trigger flare
How does allopurinol work?
It is a xanthine oxidase inhibitor which prevents uric acid from forming
What can be a side effect of allopurinol?
Rashes
When is febuxostat used?
If allopurinol cannot be tolerated.
What are cautions with febuxostat?
Renal impairment
Caution in ischaemic HD
What is a uricosuric and give an example.
Increases excretion of uric acid in the urine
Benzbromarone
When would steroids be used?
Connective tissue disease
Polymyalgia rheumatica
Vaculitis
RA
What modes of administration can be used for steroids?
Oral
IM
Intra-articular
IV
What can be adverse effects of corticosteroids?
Weight gain Muscle wasting Osteoporosis Diabetes Skin atrophy
How can the toxicity of steroids be reduced?
Lowest dose for the shortest time
Osteoporosis prophylaxis
Why are cox-2 inhibitors less likely to cause peptic ulcers?
Target only cox-2 receptors so affects acid secretion less
A patient is feeling nauseous while taking methotrexate. What can you do?
Change to methotrexate subcutaneously.
What is the benefit of using etanercept over infliximab?
Can be self given via a pen device.
How is the DAS28 score calcuated?
Number of 28 joints that are swollen
Number of 28 joints that are tender
Patient rating 1- 10 of how disease is
What DAS28 score allows a patient to have an anti-TNF?
> 5.1
