Musculoskeletal System Flashcards
What are the main indications of NSAIDs
- mild-moderate pain
- pain related to inflammation
What is the MOA of NSAIDs?
Inhibit COX (cyclo-oxygenase) to inhibit prostaglandin synthesis.
COX exists as 2 main isoforms:
- COX-1 = constitutive form: stimulates prostaglandin synthesis essential to preserve integrity of gastric mucosa, dilates afferent glomerular arterioles which maintains renal perfusion, and inhibits thrombus formation at the vascular endothelium
- COX-2 = inducible form, expressed in response to inflammatory stimuli. It stimulates production of prostaglandins that cause inflammation and pain
- Therapeutic benefits principally mediated by COX-2 inhibition
- Adverse effects principally mediated by COX-1 inhibition
- Although there is some overlap between the 2
Selective COX-2 inhibitors (e.g. etoricoxib) were developed to reduce the adverse GI effects
What are the main side effects of NSAIDs?
- GI toxicity
- Renal impairment
- increased risk of cardiovascular events.
What are the key contraindications of NSAIDs?
- Severe renal impairment
- HF
- Liver failure
- Known NSAID hypersensitivity
pts at high risk of adverse effects e.g:
- PUD
- GI bleeding
- CVD
- Renal impairment
What are the key interactions of NSAIDs?
Peptic ulceration
- Low-dose aspirin
- Corticosteroids e.g. prednisolone
GI bleeding
- Antioagulants e.g. warfarin, DOACs
- SSRIs
- Venlafaxine
Renal impairment
- ACEi
- Diuretics
Give some examples of bisphosphonates?
- Alendronic acid
- Pamidronate and zoledronic
What are the main indications for Bisphosphonates?
- those at risk of osteoporotic fragility fractures.
- severe hypercalcaemia
- Paget’s disease
What is the MOA of Bisphosphonates?
Inhibit the action of osteoclasts (which are responsible for bone resorption) and promotes apoptosis of osteoclasts which:
- Reduces bone turnover
- Reduction in bone loss
- Improvement in bone mass
What are the main side effects of Bisphosphonates?
common:
- oesophagitis
- hypophosphatemia
Rare:
- osteonecrosis of the jaw
- atypical femoral fracture
Whom are Bisphosphonates contraindicated in?
- severe renal impairment
- hypocalcaemia
- GI disorders don’t give oral
- caution- smokers, dental disease
What are the key interactions of Bisphosphonates?
- calcium salts (including milk)
- antacids
- iron salts
What are the main indications of Allopurinol
- to prevent recurrent gout attacks
- to prevent uric acid and calcium oxalate renal stones
- to prevent hyperuricaemia and tumor lysis syndrome associated with chemotherapy
What are the key contraindications of Allopurinol?
- acute attacks of gout
- Recurrent skin rash or signs of more severe hypersensitivity to allopurinol
Reduce doses in pts with:
- Renal impairment
- Hepatic impairment
What are the common side effects of Allopurinol?
- starting it can trigger/ worsen a gout attack
Common Side effects:
- skin rash (stevens-johnson syndrome or toxic epidermal necrolysis)
What are the rare side effects of Allopurinol?
Rare, life-threatening: allopurinol hypersensitivity syndrome
- Fever
- Eosinophilia
- Lymphadenopathy
- Involvement of other organs e.g. skin and liver