MSK drugs Flashcards
What is colchicine? Safety? Suitability? Dosage?
What is it?
Plant alkaloid
- Anti-inflammatory
- acts to inhibit granulocytes migration by depolarising microtubules
Safety:
- Short term= nashua & diarrhoea (dose dependent)!
Long term= bone marrow suppression & renal failure
Suitability:
- Good alternative for NSAIDs
- Similar suitability to naproxen but 2x greater diarrhoea
Dosage:
- 0.5mg for 3-4 days
- Stop if diarrhoea/ vomiting- should not exceed 6mg in 1 course, low-dose can be used for longer periods to stop recurrent flares
What are corticosteroids? Safety? Suitability? Examples? MOA?
What is it?
- Anti-inflammatory
- Local injection for single joint
- oral systemic tablets if several joints are affected
Safety:
- Short-term= generally okay
Long-term= osteoporosis
Suitability:
- those who cannot have NSAIDs or colchicine
Examples:
- cortisone
- prednisolone
MOA:
- Inhibit arachidonic acid production
- Cytokine inhibition
- Inhibition of enzyme induction
- Inhibition of T cell proliferation
- induction of apoptosis
What is allopurinol? Dosage? Suitability?Interaction? Contra-indications?
What is it?
- Inhibits xanthine oxidase
- Reduces uric acid production
Dosage:
- 100mg daily initially
- Adjust dose by serum levels (100-600mg daily) & adjust by renal failure
Suitability:
- 1st choice drug, often life-long
Interactions:
- Purine analogs & theophylline
Conta-indications:
- Allergy
- Acute gout attack
- Hepatic or renal problems
- Thyroid problems
What is Febuxostat? NICE? Suitability? Interactions?
What is it?
- Non-purine xanthine oxidase inhibitor
NICE:
- If patient’s can’t take allopurinol for medical reasons or
- If the side effects of allopurinol are so bad that the person can’t take the recommended amount
Suitability:
- Increased risk of cardiovascular problems
Interactions:
- Azathiopurine (rheumatoid arthritis treatment)
- Mercaptopurine (cancer and immune conditions treatment)
- Didanosine (HIV treatment)
What are Bisphosphonates? Safety? Suitability? Examples? MOA?
What is it?
- Analogues of pyrophosphate
- Attach to bone crystals & inhibit osteoclast breakdown of bone
- Best established agents in osteoporosis
- E.g. are alendronic acid, soledronic acid, pamidronate, ibandronate
Safety:
- GI upset- acid reflux- important side effect- take when sitting up
- Crosses placenta (unsure of effects on foetus so stop 3 months before having a baby)
- can cause jaw osteonecrosis- so need regular dental check up!
Alendronic acid:
- GI upset- bloating. reflux
- take in morning, sitting up straight w/ glass of water
Suitability:
- Life-long adherence is difficult
Zolendronic acid:
- IV injection available
- Takes 20 minutes +
- Given once a year
Pamidronic acid/pamidronate
- Infusion
- Takes ~1 hour
- Repeated every 3 months
Ibandronic acid/ibandronate
- PO (oral admin) = monthly
- IV injection = every 3 months
- Takes second
MOA:
- Reduce osteoclast activity
- Bisphophonates take up rapidly w/in bone
- When osteoclasts start to activate- they release enzyme & engulf bone
- Bisphosphonate causes death/ reduces function of osteoclasts
What is denosumab? Safety? Suitability? Dosage?
What is it?
- Monoclonal antibody - RANKL inhibitor
- binds to RANKL & acts as a competitive inhibitor
- Reduces osteoclast activation, differentiation & survival
Safety:
- Reasonable- not taken if pregnant/ during child-bearing
Suitability:
- Recommended by NICE if patient cannot have biphosphonate
Dosage:
- 1 subcutaneous injection every 6 months
MOA of paracetamol?
Similar MOA as NSAID, however pathway is unclear
Reversible non-competitive inhibition of COX-3
Provides analgesia (reduces pain) & antipyretic (reduces fever), not not anti-inflammatory
High doses can lead to liver toxicity
What are opioids? How do they reduce pain? Examples?
What are they?
- type of narcotic that binds too opioid receptors on nerve cells in brain, spinal cord & other body parts
- blocks pain messages sent from body through spinal cord to brain
- Main receptor that causes pain relief is Mu receptor
How do they reduce pain:
- Inhibit the ascending pathway- which transmits pain signals to the brain for pain perception
- Activating the descending pathway- which blocks the ascending pathway to stop pain perception
Examples:
- Morphine
- Codeine
- oxycodone
- fentanyl
What drugs are used for acute treatment for Gout?
NSAID
Cochicine
Corticosteroid
What drugs are used for chronic treatment for Gout?
Focuses on prevention!
Regular treatment to lower uric acid levels if there have been >2 acute attacks in a year & there has been renal damage or other complications
Prevention drugs:
- Allopurinol
- Febuxostat
What drugs are used for Osteoporosis?
Biphosphonates
Denosumab
Vitamin D + Calcium
Drugs used for ankylosing spondylitis?
- Adalimumab
- Etanercept
Drugs used for psoriatic arthritis?
- Adalimumab
- Etanercept
- Infliximab
Drugs used for SLE?
- Belimumab
- Hydroxychloroquine
- Corticosteroids
What are PPI?
Proton-pump inhibitors
protects lining of the stomach
Relieve symptoms of acid reflux & ulcers in stomach!
E.g. Lansoprazole
