Neuromuscular disorders

Question 1

Drugs that enhance neuromuscular transmission:

Answer 1

 Anticholinesterases (Neostigmine, Pyridostigmine) are used 1st line in ocular myasthenia gravis + as an adjunct to immunosuppressant therapy (CS, MTX, Azathioprine) for generalised myasthenia gravis.

Question 2

If anticholinesterases do not control symptoms completely give:

Answer 2

 Corticosteroids (prednisolone) on alternate days with azathioprine (allows lower maintenance dose of corticosteroid)

Question 3

Anticholinesterases enhance …

Answer 3

 transmission in voluntary and involuntary muscles in myasthenia gravis

Question 4

Signs of Anticholinesterases overdosage:

Answer 4

 bronchoconstriction, increased bronchial secretions, lacrimation, heart block, excessive sweating, involuntary defaecation, involuntary micturition, miosis, nystagmus, bradycardia, arrhythmias, hypotension, agitation, excess dreaming, weakness leading to fasciculation + paralysis.

Question 5

Muscarinic effects of Anticholinesterases:

Answer 5

 Increased –> sweating, salivary + gastric secretions, GI + uterine motility + bradycardia

Question 6

Antimuscarinics antagonise these effects …

Answer 6

 Atropine/Propantheline (prevent colic, salivation, diarrhoea)

Question 7

Antimuscarinics antagonise these effects

Answer 7

 Muscle relaxants are used for chronic muscle spasm or spasticity linked with Multiple Sclerosis or other neurological damage.

Question 8

which Muscle relaxants act on CNS

Answer 8

 Baclofen, Diazepam, Tizanidine

Question 9

which Muscle relaxants have peripheral site of action

Answer 9

 Dantrolene

Question 10

which Muscle relaxants have peripheral site of action + act on CNS

Answer 10

 Cannabis extract (dronabinol & cannabidiol)

Question 11

Baclofen (GABA analogue):

MHRA:

Answer 11

Treatment with continuous pump-administered intrathecal Baclofen should be initiated within 3 months of a satisfactory response to intrathecal baclofen testing.

Question 12

Baclofen (GABA analogue):

Treatment cessation:

Answer 12

AVOID abrupt withdrawal (risk of hyperactive state, may exacerbate spasticity and cause
hyperthermia, psychiatric reactions and convulsions.) To minimise risk, discontinue gradually by reducing dose over at least 1-2 weeks (longer if symptoms occur).

Question 13

Baclofen (GABA analogue):

Patient advice:

Answer 13

drowsiness may occur, do not drive or use tools/machinery. Baclofen enhances effects of alcohol

Question 14

Febuxostat:
MHRA:

Answer 14

There has been rare but serious reports of hypersensitivity reactions, including Stevens-Johnson syndrome and acute anaphylactic shock with Febuxostat.
- Advise patients of the signs and symptoms of severe hypersensitivity; STOP Febuxostat immediately if these occur + do not start again in patients who have developed hypersensitivity to Febuxostat.

Question 15

Nocturnal Leg Cramps

- First Line:

Answer 15

Non-pharmacological e.g. Passive stretching exercises

Question 16

Nocturnal Leg Cramps

- Second Line:

Answer 16

• (frequent, painful & regular sleep disruption): Quinine Salts at night (SE: QT prolongation, convulsions, arrythmias). Quinine Bisulfate < salt than other Quinine salts

Question 17

Nocturnal Leg Cramps - Monitoring:

Answer 17

• 4 weeks before improvement seen then continue if benefit. Review after approx. 3 months to ..assess for further need of treatment