CNS Part 2 November 23

Question 1

Question

Answer 1

Answer

Question 2

A58: What are the main symptoms of myoclonic seizures and what drugs are used to treat it? (M)

Answer 2

Symptoms: Contraction of muscles causing jerks; may affect whole body or just one or both arms. Drugs: Ethosuximide, Sodium valproate, Lamotrigine, Levetiracetam.

Question 3

A59: What are the main symptoms of tonic-atonic seizures and what drugs are used to treat it? (S)

Answer 3

Symptoms: Brief loss of consciousness, stiffening, falling to the ground. Drugs: Sodium valproate, Lamotrigine, Rufinamide, Clonazepam, Topiramate.

Question 4

A60: What drugs are used to treat focal seizures? (G)

Answer 4

1st line: Lamotrigine, Levetiracetam; 2nd line: Carbamazepine, Oxcarbazepine, Zonisamide; 3rd line: Lacosamide.

Question 5

A61: What are the 2 main types of focal seizures and their symptoms? (R)

Answer 5

Simple: Muscular jerks, 1 side of the brain affected, odd mood (no loss of consciousness); Complex: No muscular jerks, 1 side of the brain affected, loss of consciousness, odd behavior, pins & needles, odd mood.

Question 6

A62: What are the main uses for carbamazepine? (M)

Answer 6

Generalized tonic-clonic seizures,
focal seizures,
diabetic neuropathy (unlicensed)
prophylaxis of bipolar disorder,
acute alcohol withdrawal,
trigeminal neuralgia.

Question 7

A63: What’s the therapeutic range of carbamazepine? (S)

Answer 7

4-12 mg/L or 20-50 micromol/L; measure 1-2 weeks after initiation.

Question 8

A64: How does carbamazepine work? (G)

Answer 8

It’s a sodium channel blocker, which stops repeated firing of nerve signals, preventing seizures.

Question 9

A65: Is carbamazepine safe in pregnancy and breastfeeding? (R)

Answer 9

Pregnancy:

Risk of defects, switch to lamotrigine or levetiracetam if possible;

Breastfeeding: It’s generally safe.

Question 10

A66: What are the main contraindications for carbamazepine? (M)

Answer 10

Acute porphyrias,
AV conduction
abnormalities (unless paced),
history of bone marrow depression.

Question 11

A67: What are the main side effects of carbamazepine?

Answer 11

MT: HANDBAG(S) - Includes
hyponatremia,
ataxia,
nystagmus,
drowsiness,
blurred vision,
arrhythmia,
gastrointestinal issues,
skin/blood disorders.

Question 12

A68: What are the main drug interactions for carbamazepine? (G)

Answer 12

Interactions with enzyme inhibitors

(increases carbamazepine levels)

and enzyme inducers

(decreases carbamazepine levels).

Also affects plasma concentrations of other drugs.

Question 13

A69: What must be done before starting carbamazepine? (R)

Answer 13

Test for HLA B* 1502 allele, especially in Asians;

FBC,
renal,
hepatic function tests.

Question 14

A70: What must be monitored when on carbamazepine and how often? (M)

Answer 14

Monitor plasma concentration (4-12mg/L or 20-50micromol/L), blood counts, hepatic and renal function, and pre-treatment screen (HLA-B*1502 allele) as needed.

Question 15

A71: What are the warning signs of taking carbamazepine? (S)

Answer 15

Dose-related side effects like HANDBAG(S), hyponatremia, ataxia, nystagmus, drowsiness, blurred vision, arrhythmia, gastrointestinal, skin/blood disorders.

Question 16

A72: What’s the main patient advice for someone taking carbamazepine? (G)

Answer 16

Stay on the same brand, consult a doctor or pharmacist before using OTC meds, and seek medical attention for certain side effects.

Question 17

A73: What formulation change can reduce side effects of carbamazepine? (R)

Answer 17

Give a modified release formulation.

Question 18

A74: What are the main uses for lamotrigine? (M)

Answer 18

Focal seizures, secondary generalized tonic-clonic seizures, bipolar disorder.

Question 19

A75: What side effect of lamotrigine is concerning, and what action should be taken? (S)

Answer 19

Serious skin reactions, like Steven-Johnsons syndrome; action is to withdraw and see a doctor.

Question 20

A76: What are the main interactions to watch out for when taking lamotrigine? (G)

Answer 20

Valproate increases lamotrigine levels, while inducers (SCRAP BS GPS) reduce it.

Question 21

A77: What are the main uses of phenytoin? (R)

Answer 21

Tonic-clonic seizures, focal seizures, prevention and treatment of seizures following or during brain surgery or head injury, status epilepticus.

Question 22

A78: What’s the therapeutic range of phenytoin? (M)

Answer 22

10-20mg/L or 40-80micromol/L.

Question 23

A79: How does phenytoin work? (S)

Answer 23

It’s a sodium channel blocker, preventing repeated firing of nerve signals. It’s also an enzyme inducer.

Question 24

A80: Is phenytoin safe in pregnancy and breastfeeding? (G)

Answer 24

Risk of defects in pregnancy; safe in breastfeeding.

Question 25

A81: What are the main contraindications for phenytoin? (R)

Answer 25

Acute porphyrias.

Question 26

A82: What are the main side effects of phenytoin? (M)

Answer 26

MT: PHENYTOIN - Includes P450 inducer, hirsutism, gingival hyperplasia, nystagmus, teratogenicity, osteopenia, interference with folic acid, neuropathy.

Question 27

A83: What are the main drug interactions for phenytoin?

Answer 27

Increased concentration with some drugs and decreased concentration with others, depending on enzyme induction or inhibition.

Question 28

A84: What must be done before starting Phenytoin? (G)

Answer 28

Pre-treatment screening for HLA-B*1502 allele in Han Chinese or Thai origin, and consider the allele’s presence in carbamazepine and phenytoin.

Question 29

A85: What must be monitored when on phenytoin and how often? (R)

Answer 29

Monitor liver function, FBC, plasma levels, ECG, BP as needed based on patient factors and clinical situation.

Question 30

A86: What are the warning signs of taking phenytoin? (M)

Answer 30

Discontinue if rash develops; report blood/skin disorders and MHRA warnings.

Question 31

A87: What’s the main patient advice for someone taking phenytoin? (S)

Answer 31

Stay on the same brand, recognize signs of blood or skin disorders, and discontinue and seek medical attention if needed.

Question 32

A88: When should treatment with phenytoin be stopped? (G)

Answer 32

Stop if signs of blood or skin disorders develop or in cases of severe, progressive leucopenia.

Question 33

A89: Which route of administration should phenytoin be avoided, and what route is preferred if oral is not suitable? (R)

Answer 33

Avoid IM administration; use oral or IV routes.

Question 34

A90: For a patient on phenytoin and immobilized for a long time, what should be considered? (M)

Answer 34

Consider giving vitamin D.

Question 35

A91: What’s the main MHRA warning regarding phenytoin? (S)

Answer 35

MHRA warnings include risk of suicidal thoughts, risk of death from injectable phenytoin, switching between different manufacturers’ products, and antiepileptic drugs in pregnancy.

Question 36

A92: What are the uses of topiramate? (G)

Answer 36

Generalized tonic-clonic or focal seizures.

Question 37

A93: What are the MHRA warnings of topiramate? (R)

Answer 37

Warnings include suicidal behavior and risk of neurodevelopmental disabilities in children born to mothers taking topiramate.

Question 38

A94: Is topiramate safe in pregnancy and breastfeeding? (M)

Answer 38

It’s not recommended unless benefits outweigh risks for both.

Question 39

A95: What are two visual side effects of topiramate? (S)

Answer 39

Visual side effects include acute myopia with secondary angle-closure glaucoma.

Question 40

A96: What should patients report if they’re taking topiramate? (G)

Answer 40

Patients should report visual problems and seek specialist advice if intraocular pressure rises.

Question 41

A97: What cautionary advisory labels should be written if someone is taking topiramate? (R)

Answer 41

Labels should include warnings about drowsiness and not stopping the medication without doctor’s instructions.

Question 42

A98: What should patients report if they’re taking ethosuximide? (M)

Answer 42

Report signs of bone marrow depression, fatigue, increased heart rate, paleness, dizziness, and blood disorders.

Question 43

A99: What are the main uses of gabapentin? (S)

Answer 43

Gabapentin is used for focal seizures and neuropathic pain.

Question 44

A100: What are the main MHRA warnings of gabapentin? (G)

Answer 44

Warnings include respiratory depression and the risk of abuse and dependence.

Question 45

A101: Is gabapentin safe in pregnancy and breastfeeding? (R)

Answer 45

It’s generally avoided unless the benefit outweighs the risk.

Question 46

A102: If someone is given clobazam, what must be written on the prescription? (M)

Answer 46

The prescription for epilepsy must be endorsed with ‘SLS’.