Neuro

Question 0

What class of drug is levodopa and how does it work ?

Answer 0

Dopamine precursor
- crosses blood brain barrier and converted not dopamine by dopa carboxylase therefore replacing deficient dopamine in basal ganglia

Question 1

What class of drug is metoclopramide

Answer 1

Antiemetic

Question 2

What are the indications for levodopa ?

Answer 2

• idiopathic Parkinson’s disease

- Parkinsonism

Question 3

What are the contraindications for levodopa?

Answer 3

• closed angle glaucoma

- drug-induced Parkinsonism

Question 4

What are the common side effects of levodopa?

Answer 4

Anorexia, nausea, vomiting, abdo pain
Insomnia, agitation, postural hypotension
Discoloured urine

Question 5

Possible interactions of levodopa ?

Answer 5

Anaesthetics: increased risk of dysrhymias

MAOIs (antidepressants): increased risk of HTN

Question 6

What drug class is phenytoin ?

Answer 6

Anticonvulsant

Question 7

Mode of action of phenytoin ?

Answer 7

Blocks voltage gated Na+ channels therefore preventing influx of sodium and so preventing spread of epileptic charge

Question 8

Indications for phenytoin ?

Answer 8

All epilepsy except absence seizures

Trigeminal neuralgia

Question 9

There are no contraindications for phenytoin, but when should you take caution ?

Answer 9

Hepatic impairment

Pregnancy/breast feeding

Question 10

Common side effects of phenytoin ?

Answer 10

Dizziness, headache, confusion, insomnia, nausea, vomiting

Question 11

Possible interactions of phenytoin ?

Answer 11

Induces hepatic drug metabolising enzyme

Question 12

What drug class is carbamazepine ?

Answer 12

Anticonvulsant

Question 13

How does carbamazepine work ?

Answer 13

Increases the release of GABA - has inhibitory role in CNS, blocking Na+ channels and so preventing positive influx of Na

Question 14

Indications for carbamazepine

Answer 14

Seizures: partial and tonic clonic (but may exacerbate absence & myoclonic)
Trigeminal neuralgia
Chronic neurogenic pain
Bipolar prophylaxis

Question 15

Contraindications of carbamazepine

Answer 15

AV conduction abnormalities

Bone marrow suppression

Question 16

Carbamazepine has cross sensitivity with which other anticonvulsants ?

Answer 16

Oxcarbazepine, phenytoin

Question 17

Interactions of carbamazepine

Answer 17

Alcohol: CNS side effects increased
Tramadol: reduced effect
Paracetamol: increased metabolism

Question 18

Side effects of carbamazepine

Answer 18

Dry mouth, nausea, vomiting,

Ataxia, dizziness, drowsiness,head ache, hyponatraemia

Question 19

What drug class is sodium valproate ?

Answer 19

Anticonvulsant

Question 20

Mode of action of sodium valproate

Answer 20

Inhibits GABA transaminase causing increased GABA in brain which has an inhibitory role preventing excitation - decreases levels of aspartate (excitatory neurotransmitter) and prevents influx of Na+

Question 21

Indications of sodium valproate ?

Answer 21

All forms of epilepsy
Migraine prophylaxis
Mania

Question 22

Contraindications of sodium valproate ?

Answer 22

Family history of severe hepatic dysfunction/active liver disease
Acute porphyria

Question 23

Common side effects of sodium valproate ?

Answer 23

GI irritation- nausea, diarrhoea
Weight gain, transient hair loss,
hyperammonaemia, thrombocytopenia

Question 24

Interactions of sodium valproate

Answer 24

Aspirin enhances effect of valproate

Question 25

What class of drug is lamotrigine ?

Answer 25

Anticonvulsant

Question 26

Mechanism of action of lamotrigine

Answer 26

Stabilises presynaptic neuronal membranes by hi biting sodium currents by selectively binding to the inactive state of of the sodium channel and subsequently suppressing release of excitatory amino acids e.g, glutamate and aspartate

Question 27

Indications for lamotrigine

Answer 27

Seizures: focal and generalised including: tonic clonic, Lennox-gestaut, absence in children - prevention of depressive episodes in bipolar

Question 28

Common side effects of lamotrigine

Answer 28

Nausea, vomiting, dry mouth, Aggression, agitation, headache, drowsiness, dizziness, tremor, insomnia, Rash

Question 29

Interactions of lamotrigine

Answer 29

``` Rifampicin- decreases plasma conc of lamotrigine MAOIs COCP- decreases plasma conc lamotrigine Carbamazepine ' ' Phenytoin- '' Valproate- increased conc lamotrigine ```

Question 30

Mode of action of metoclopramide

Answer 30

Acts on chemoreceptors in trigger zone of brain stem to block dopamine receptors causing relaxation of pylori. Sphincter, increased rate of gastric/duodenal emptying

Question 31

Indications for metoclopramide

Answer 31

Nausea and vomiting | GORD

Question 32

Contraindications of metoclopramide

Answer 32

Parkinsonism Recent gastric surgery (within last few days) Intestinal obstruction

Question 33

Side effects of metoclopramide

Answer 33

Common : acute dystonia reactions (muscle spasms)

Question 34

Possible interactions of metoclopramide

Answer 34

NSAIDs- increased absorption of the, and therefore increased side effects