BNF - Chapter 10 - Musculoskeletal System Flashcards
What is used for pain relief in osteoarthritis?
Simple analgesics such as paracetamol or topical NSAID (particularly for hand or knee involvement) is first-line treatment
What if treatment with simple analgesic is ineffective?
Then consider oral NSAID when required (topical NSAID use should be discontinued), or a weak opioid analgesic (such as codeine phosphate) when required or topical Capsaicin 0.0025%, particularly in the knee or hand osteoarthritis
What about in patients with osteoarthritis who are taking low-dose aspirin?
In these patients, other analgesic treatment options should be considered before using a NSAID
What can be considered for relief of moderate to severe pain associated with osteoarthiritis?
Intra-articular corticosteroid injections
What are some non-drug measures for osteoarthriris?
Weight reduction (in overweight or obese patients) and exercise including local muscle strengthening and aerobic exercise, should also be encouraged
Are Glucosamine containing products recommended for osteoarthrirtis?
No - Glucosamine, chondroitin, and topical rubefacients (which may contain nicotinate compounds, salicylate compounds, essential oils, and camphor) are not recommended for the treatment of osteoarthritis
What is rheumatoid arthritis?
It is an autoimmmune disease where the immune system mistakenly attacks the synovium (lining of the joints)
What are the symptoms of RA?
Joint pain and swelling, usually affects hands, feet an wrists
What does DMARDs stand for?
Disease modifying anti-rheumatic drugs
Which DMARDs are used in Arthritis?
Sulfasalzine (blood dyscrasis, colours bodily secretions orange/yellow)
Penicillamine (Blood dyscrasis)
Gold (Blood Dyscrasis)
Which anti-malarial is considered a DMARD?
Hydroxychloroquine/ Chloroquine (Screening for ocular toxicity)
Which DMARDs are used which affect the immune response? (they all cause blood dyscrasis)
- Methotrexate
- Azathioprine
- Ciclosporin (nephrotoxic)
- Leflunamide (hepatoxic, Effective contraception for 2 years after treatment for women and 3 months after treatment for men)
- Cyclophosphamide (cytotoxic drug, urothelial toxicity i.e. haemorrhagic cystitis and permanent male sterility)
List the Cytokine modulators - DMARDS?
- Infliximab
- Etanercept
(Blood dyscrasis, report symptoms of tuberculosis e.g. persistent cough, weight loss and fever)
With which drugs if given with methotrexate can increase the risk of hepatoxicity?
- Isotretinoin
- Phenothiazine antipsychotics
- Rifampicin
- Ketoconazole
All are hepatoxic drugs
What is the treatment for juvenile idiopathic arthritis?
Methotrexate is effective;
Sulfasalazine is an alternative (unlicensed)
What type of immunosuppressant is etanercept?
Tumour necrosis factor alpha(TNF-alpha) inhibitor
What is gout?
Gout is a condition that causes sudden severe pain, swelling and redness in the joints, caused by the accumulation of uric acid crystals forming in the joints
BNF - Gout is a common form of inflammatory arthritis characterised by raised uric acid concentration in the blood (hyperuricaemia) and the deposition of urate crystals in joints and other tissues.
Which drugs can cause hyperuricaemia?
- Diuretics (loop and thiazides)
- Ciclosporin, Tacrolimus
- Cytotoxic
- Cancer
The management of gout under what age requires specialist supervision?
Under the age of 30
What are acute attacks of gout treated with?
With either colchicine or high doses of an NSAID (excluding aspirin)
What should be co-prescribed in patients prescribed an NSAID?
A gastro-protective drug (such as a proton pump-inhibitor)
What is the use of colchicine limited by?
By the development of toxicity at higher doses;
However, unlike NSAIDs it does not induce fluid retention, moreover it can be co-administered with anticoagulants
What can be considered in those who cannot tolerate NSAIDs or colchicine and when intra-articular injection is not suitable for acute attack of gout?
A short course of oral corticosteroid
For long-term control of gout, the formation of uric acid from purines may be reduced with which drugs?
xanthine-oxidase inhibitors
- allopurinol or febuxostat
Which is recommended as first-line urate-lowering therapy?
Allopurinol where renal function allows;
Febuxostat can be used as an alternative when allopurinol is contra-indicated or not tolerated
If an acute attack develops during urate-lowering therapy long term therapy, what should happen to the urate-lowering therapy?
the urate-lowering therapy should continue at the same dosage and the acute attack treated separately.
What is the instruction directions for gout?
Max dose - 500micrograms 2-4 times a day
Max 6mg per course
Do not repeat course within 3 days
What should be noted about starting a prevention treatment (urate-lowering therapy) for gout?
Never start during an acute attack - start preventative treatment 1-2 weeks after an acute attack
Initiation may precipitate an acute attack - may need to continue colchicine for up to 6 months
What side effect with allopurinol should you look out for?
Rash - if mild reintroduce slowly. Stop if it occurs again
How should you take allopurinol?
With or after food
What should you do if allopurinol is given with mercaptopurine/ azathioprine?
Reduce dose of mercaptopurine/ azathioprine (half the dose) - increased risk of toxicity
What has been reported with febuxostat?
rare but serious reports of hypersensitivity reactions, including Steven’s-Johnson syndrome and acute anaphylactic shock
What is myasthenia gravis (MG)?
It is a chronic autoimmune disorder in which antibodies destroy the communication between nerves and muscle, resulting in weakness of the skeletal muscles.
Myasthenia gravis affects the voluntary muscles of the body, especially those that control the eyes, mouth, throat and limbs
What is used first line for treatment in ocular myasthenia gravis as an adjunct to immunosuppressant therapy for generalised myasthenia gravis?
Anticholinesterases (Drugs that enhance neuromuscular transmission)
When anticholinesterases do not control symptoms completely then which drugs are used next?
Corticosteroids are used when anticholinesterases do not control symptoms completely. A second line immunosuppressant such as azathioprine is frequently used to reduce the dose of corticosteroid.
Excessive dosage of anticholinsterase can cause what?
Can impair neuromuscular transmission and precipitate cholinergic crises by causing a depolarising block
This may make it difficult to distinguish from a worsening myasthenic state
What are the Muscarinic side effects of anticholinesterases?
- increased sweating
- increased salivary and gastric secretions
- increased gastro-intestinal and uterine motility
- bradycardia
These parasympathomimetic effects are antagonised by which drug?
By atropine sulfate
Which anticholinesterase can be used for myasthenia gravis?
Neostigmine
How long does neostigmine produce its therapeutic effect for?
For up to 4 hours
Why is the pronounced muscarinic action of neostigmine a disadvanatge?
Its pronounced muscarinic action is a disadvantage, and simultaneous administration of an antimuscarinic drug such as atropine sulfate or propantheline bromide may be required to prevent colic, excessive salivation, or diarrhoea
In severe disease, neostigmine can be given how often?
every 2 hours
What is the maximum daily dose of neostigmine that patients can tolerate?
180mg daily
Compare neostigmine to pyridostigmine bromide in terms of onset of action and duration of action?
Pyridostigmine bromide is less powerful and slower in action than neostigmine but it has a longer duration of action
Why is pyridostigmine preferred over neostigmine?
It is preferable to neostigmine because of its smoother action and the need for less frequent dosage.
It is particularly preferred in patients whose muscles are weak on waking
It has a comparatively mild gastrointestinal effect but an antimuscarinic drug may still be required.
When corticosteroids are used for myasthenia gravis is it given daily?
Commonly given on alternate days
In generalised myasthenia gravis which corticosteroid is used?
Prednisolone is given alone
How many patients may experience a transient but very serious worsening of symptoms in the first 2-3 weeks, especially if the corticosteroid is started at a high dose?
About 10%
Is larger or smaller doses required in ocular myasthenia gravis?
Smaller doses of corticosteroids
In generalised myasthenia gravis which drug is usually started at the same time as the corticosteroid which allows a lower maintenance dose of the corticosteroid to be used?
Azathioprine
What are skeletal muscle relaxants used for?
They are used for the relief of chronic muscle spasm or spasticity associated with multiliple sclerosis or other neurological damage; they are not indicated for spasm associated with minor injuries
Which skeletal muscle relaxants act principillay on the central nervous system?
- Baclofen
- Diazepam
- Tizanidine
What about dantrolene?
Peripheral site of action
Where does cannabis extract act?
both central and a peripeheral action
What is the major disadvantage of treatment with these drugs?
The reduction in muscle tone can cause a loss of splinting action of the spastic leg and trunk and sometimes lead to an increase in disability
What does baclofen inhibit?
Baclofen inhibits transmission at spinal level and also depresses the central nervous system. The dose should be increased slowly to avoid the major side-effects of sedation and muscular hypotonia (other adverse events are uncommon).
Does dantrolene sodium cause alot of Central adverse effects?
No - Dantrolene sodium acts directly on skeletal muscle and produces fewer central adverse effects making it a drug of choice. The dose should be increased slowly.
What drug class does tizanidine belong to?
It is an alpha2-adrenoceptor agonist indicated for spasticity associated with multiple sclerosis or spinal cord injury
When can cannabis extract be tried?
Cannabis extract can be trialled as an adjunct treatment for moderate to severe spasticity in multiple sclerosis if other pharmacological treatments are not effective. Treatment must be initiated and supervised by a specialist.