Musculoskeletal System Flashcards
(38 cards)
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
What are the key interactions of allopurinol?
- Azathioprine increases the risk of toxicity of allopurinol
Risk of hypersensitivity reaction increased by co-prescription with:
- ACE inhibitors
- Thiazides
- Amoxicillin (increases the risk of skin rash)
What are the main indications for Colchicine?
- acute gout
- short-term prophylaxis of gout flares
- familial mediterranean fever
What are the main side effects of colchicine?
- abdominal pain
- Diarrhoea
- Nausea
- vommiting
- Agranulocytosis
- Thrombocytopenia
What are the key contraindications of Colchicine?
- hepatic impairment
- pregnancy
- breastfeeding
- eGFR <10
What are the key interactions og Colchicine?
CHECK 100 DRUG BOOK
What are the main indications of Paracetamol?
- acute and chronic pain
- Antipyretic that can reduce fever and its associated symptoms (e.g. shivering)
What is the MOA of paracetamol?
A weak inhibitor of COX which is involved in prostaglandin metabolism.
COX inhibition increases pain threshold and reduces prostaglandin E2 concentrations in the thermoregulatory region of the hypothalamus, controlling fever.
Has specificity for COX-2 however is a weak anti-inflammatory
- Actions limited by the presence of peroxides
What are the main side effects of paracetamol?
In overdose may cause liver failure
- Hepatotoxicity can be prevented by treatment with the glutathione precursor acetylcysteine
What are the key contraindications of Paracetamol?
- liver toxicity
- chronic excessive alcohol use
- low body weight
