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Flashcards in Clinical Pharmocology Deck (40):
1

 

 

What are examples of benzodiazepines?

 

  • Midazolam
  • Diazepam
  • Lorazepam

2

 

 

When are benzodiazepines indicated for use?

 

  • Seizure termination
  • Severe panic disorders
  • Anxiety disorders - short term only
  • Insomnia - short term
  • Alcohol withdrawal
  • Perioperative sedation

3

 

 

When are benzodiazepines contraindicated for use?

 

  • Resp muscle weakness
  • Sleep apnoea
  • COPD
  • Pregnancy
  • Breast feeding

4

 

 

How do Benzodiazepines work?

 

 

Potentiate GABA neurotransmission

5

 

 

What are edverse drug reactions to benzodiazepines?

Features of Over-sedation

  • Drowsiness
  • In-coordination
  • Muscle weakness
  • Dizziness
  • Confusion
  • Respiratory arrest

6

 

 

What is the half-life of midazolam?

 

 

2 hours

7

 

 

What is the half-life of lorazepam?

 

 

8 hours

8

 

 

What is the half-liofe of diazepam?

 

 

30 hours

9

 

 

What are examples of triptans?

 

 

Sumatriptan

10

 

 

when are triptans indicated for use?

 

 

Migraines

11

 

 

When are triptans contraindicated?

 

  • IHD
  • Coronary Vasospasm
  • Previous MI
  • Uncontrolled/severe hypertension

12

 

 

How do triptans work?



Triptans are 5-HT1D receptor agonists and therefore block the receptors so 5-HT is unable to bind to the receptor on the vascular endothelium. This is thought to stop 5-HT (serotonin)  from stimulating the vascular endothelium to release nitric oxide, causing vasodilation with stimulation of meningeal sensory nerve endings. 

13

 

 

What are common side effects of triptans?

 

  • Sensations of tingling, heat, pressure or tightness in any part of the body.
  • Dizziness
  • Weakness
  • Fatigue
  • Nausea and vomiting
  • Drowsiness

Can also have - dyspepsia, Abdo pain, Tachycardia, myalgia, med-overuse headache

14

 

 

What should you be very careful giving triptans with?

 

 

SSRI's - both together can cause serotonin syndrome

15

 

 

What are indications for using carbemazepine?

 

  • Generalised/focal seizures
  • Trigeminal neuralgia

16

 

 

What is the mechanism of action of carbemazepine?

 

Acts by binding to the sodium channels of neuronal membranes and prevents the influx of sodium into the cell which normally leads to an action potential. By preventing depolarisation of these neurones, there is not the repeated "firing" of action potentials that is responsible for epileptic seizures.

17

 

 

What are side effects of carbemazepine?

  • Stevens - Johnson syndrome
  • Toxic Epidermal Necrolysis
  • SIADH
  • Nausea and vomiting
  • Dry mouth
  • Peripheral Oedema, weight gain
  • Dizziness
  • Drowsiness and fatigue
  • Headache
  • Abnormal LFTs

18

 

 

What are indications for the use of lamotrigine?

 

 

Partial/generalised seizures

19

 

 

How does lamotrigine work?

 

Acts as a sodium channel blocker, to reduce the influx of sodium ions into neurones, and therefore reduced action potentials. This effectively stops the neurones from repetitively "firing" and therefore prevents seizures.

20

 

 

What are the side effects of lamotrigine?

 

  • Rashes
  • Nausea, vomiting and diarrhoea
  • Somnolence or insomnia
  • Headache
  • Dizziness
  • Blurred vision or diplopia
  • Ataxia
  • Hypersensitivity syndrome
  • Haematological abnormalities

21

 

 

When is levetiracetam indicated for use?

 

 

Monotherapy/adjunct for focal seizures

22

 

 

How does Levetiracetam work?

 

 It is an effective anticonvulant but little is known about its mode of action - it does not increase GABA in the brain or have an effect of ion channels. It does appear to bind to a synaptic vesicle protein SV2A which may impede nerve conduction across synapses.

 

23

 

 

What are side effects of levetiracetam?

 

  • Psychiatric disturbance - aggression, agitation, depression
  • Nausea and vomiting and anorexia
  • Tremor and hyperkinesias
  • Diarrhoea
  • Drowsiness
  • Diplopia
  • Blood dycarias

24

 

 

What are indications for phenytoin?

 

  • Termination of status epilepticus
  • Trigeminal neuralgia

25

 

 

 

How does phenytoin work?

 

Binds to this sodium channel (sodium channel blocker), and reduces the influx of sodium into the cell which would lead to an action potential, and therefore reduces the depolarisation of the neurones which are responsible for epileptic seizures. 

 

26

 

 

What are side effects of phenytoin?

  • Nausea and vomiting
  • Constipation
  • Drowsiness
  • Headache
  • Tremor
  • Rashes
  • Acne
  • Hirsutism
  • Gingival hypertrophy
  • Hepatotoxicity
  • Blood disorders (anaemia, leucopenia, thrombocytopenia)
  • Stevens-Johnson syndrome

27

 

 

What are features of phenytoin toxicity?

 

  • Vertigo
  • Ataxia
  • Nystagmus
  • Confusion

28

 

 

What is the therapeutic window for phenytoin?

 

 

5-20 mg/L

29

 

 

What are indications for sodium valproate?

 

  • Commonly used in all forms of epilepsy. 
  • Partial and generalised epilepsy
  • Sometimes used in bipolar affective disorder. 
  • Occasionally in migraine prophylaxis.

30

 

 

What is sodium valproate particularly good at managing?

 

 

Juvenile myoclonic epilepsy

31

 

 

What are contraindications for sodium valproate use?

 

  • Liver dysfunction/failure
  • Pregnancy

32

 

 

How does sodium valproate work?

 

  • Increasing the amount of GABA in the brain - inhibits GABA transaminase
  • Blocking Sodium Channels
  • Blocking Calcium Channels

33

 

 

What are side effects of sodium valproate?

 

  • Most serious side effects - sudden onset of liver failure, acute pancreatitis and severe thrombocytopenia. 
  • Nausea and vomiting
  • Diarrhoea
  • Weight gain
  • Oedema
  • Hallucinations

34

 

 

What are indications for gabapentin use?

 

  • Monotherapy or adjunctive therapy in focal seizures
  • Neuropathic pain
  • Migraine prophylaxis.

35

 

 

What is the mechanism of action of gabapentin?

 

The precise mechanism of Gabapentin is unknown. However the main mechanism of action seems to be by blocking T-type calcium channels and inhibiting other modulators and neurotransmitters.

36

 

 

What are adverse reactions to gabapentin use?

 

  • Nausea, vomiting & diarrhoea
  • Abdominal pain & constipation
  • Hypertension
  • Headache
  • Ataxia
  • Mood changes and depression

 

37

 

 

What epileptic medications act by inhibiting sodium dependent action potentials?

 

  • Carbamazepine
  • Phenytoin
  • Lamotrigine

38

 

 

What epileptic medications act by inhibiting voltage gated calcium channels?

 

 

Phenytoin

39

 

 

What medications act by potentiating GABA receptor function?

 

 

Benzodiazepines

40

 

 

What epileptic medications work by increasing GABA availibility?

 

  • Valproate
  • Gabapentin