BZP

Question 1

anxiolytics vs hypnotics

Answer 1

• Anxiolytics (sedatives): induce sleep ON – PD, GAD
• Hypnotics (sleeping pills): sedate when OM
  ○ BZP, Z-hypnotics, antihistamines, melatonin receptor agonist, lemborexant
  ○ Off-label: antidep Trazodone, antipyshotics

Question 2

BZP MOA

Answer 2

potentiates GABA relieves ANX and insomnia

a2, a3: relief anxiety
a5: cognition

Question 3

BZP SE

Answer 3

seadation, drowsy, amnesia

muscle weak, ataxia (incoord), vertigo, headache, slurr speech

paradoxical excitement

Question 4

dose for BZP

Answer 4

short term 2-4wks, low dose

lora: 0.5-2mg PRN (t1/2 12hr)
diazepam: 2-15mg PRN (t1/2: 20-54hr)

Question 5

z-hypnotics MOA

Answer 5

Zopiclone, eszopiclone, zaleplon and zolpidem

bind to BZP-binding site with y and a1 subunits (cause sedation)
* but not same site as BZP (no anxiolytic effect) a2,a3

Question 6

z-hypnotics SE

Answer 6

taste disturbance (metallic zopiclone), complex sleep behaviour (sleep walk)

NV, dizzy, headache

no muscle weakness

Question 7

z-hypnotics dose

Answer 7

same caution as BZP (tolerance, dependence)

zopiclone (>18yo) 7.5mg PRN (t1/2 6hr)
* 50% dose for elderly

zolpidem (>18yo) 10mg PRN (t1/2 1.5-4hr)
* 50% dose for females and elderly

Question 8

antihistamines MOA

Answer 8

promethazine, hydroxyzine

H1 antagonism

Question 9

ANTIHISTAMINE ADR

Answer 9

sedation, dry mouth, constipation, urinary retention

Question 10

antihist dose

Answer 10

25-50mg PRN promethazine/ hydroxyzine

less risk of dependence, but not suitable for elderly

Question 11

melatonin receptor agonist MOA

Answer 11

melatonin 1,2 agonist

circadine/ melatonin, ramelteon

Question 12

MRA dose and SE

Answer 12

headache

circadin: 2mg (1-2hr before bed, after food) ~13wks
>55yo
low risk of dependence

Question 13

lemborexant MOA

Answer 13

OX1 and OX2 orexin receptor antagonist

neuropeptide that regulates arousal, wakefulness, and appetite.

Question 14

lemborexant SE

Answer 14

somnolence, sleep paralysis, nightmare, halluination

Question 15

lemborexant dose and CI

Answer 15

5-10mg PRN (t1/2: 17-19hrs)

less tolerance, dependence risk

CI: nacrolepsy (daytime sleepy)/ hep impair/ CYP3A4 mod-strong inducer, inhibitor

Question 16

off-label hypnotics

Answer 16

antidep (trazodone): antagonise 5HT2A, H1, A1

antipsychotics: for agitated behaviour in acute psychosis, low risk of dependence

Question 17

BZP and Z-HYPNOTICS CI

par smh

Answer 17

○ Acute narrow angle glaucoma
○ Acute pul insuff
○ Resp depression, sleep apnoea syndrome, marked neuromuscular resp weakness (myasthenia gravis)
○Hypersensitivity to drug, excipients

Question 18

additional BZP precautions

Answer 18

○ Renal, hep impairment (severe)
○ Children, elderly, debilitated
○ Preg, BF (unless benefit > risk)
○ Hx of alcohol, drug abuse or psychiatric d.o
* Marked personality d/o, depression, psychosis

Question 19

antihistamine CI

Answer 19

• anticholinergic: Prostatic hypertrophy, urinary constipation, angle closure glaucoma, pyloroduodenal obstruction
• Epilepsy, QTc interval prolongation (HYDROXY)
• Coronary artery disease (PROMETHAZINE)

Question 20

BZP use caution

Answer 20

• Prolonged use, abrupt discontinuation
  ○ Tolerance builds with high dose daily use
  ○ Gradual dose tapering if used for wks/mnths – rebound ANX/ withdrawal seizure
  * 25% weekly decr until 50% of dose
  * 12.5% every 4-7day
• Omit BZP before ECT
• DDI with opioids = MORTALITY
  ○ CNS depression