Benzos

Question 1

What are the GABAergic sedative-hypnotic drugs?

Answer 1

• chloral hydrate
• meprobamate
• barbiturates
• benzos
• z-drugs

Question 2

Which drug has a more narrow TI compared to benzos

Answer 2

barbiturates

Question 3

What barbiturates are still used in hospital settings?

Answer 3

• secobarbital/amobarbital/thiopental (sedation and anesthesia)
• phenobarbital (status epilepticus)

Question 4

What barbiturates are used in community pharmacy?

Answer 4

• phenobarbital (refractory epilepsy)

- secobarbital/pentobarbital (MAID)

Question 5

Are benzo overdoses in isolation ever fatal?

Answer 5

NO

Question 6

What are the predisposing factors that increase the risk of overdose with benzos?

Answer 6

• age
• hepatic impairment
• COPD

Question 7

What are the toxidrome of CNS s/s associated with benzos

Answer 7

• mild: drowsiness or lethargy after 30-60 mins of ingestion
• moderate: slurred speech, amnesia, and ataxia may appear shortly after
• severe sx: stupor or coma may occur hours after large ingestions alone or sooner if polydrug overdose (hypothermia, hyporeflexia, myosis)
• rare: paradoxical rxns- agitation, aggression with confusion may occur

Question 8

What are the different orders of respiratory effects among these drugs?

Answer 8

barbiturates > benzos > z drugs

Question 9

If a person has CNS depression, will they also likely have respiration depression?

Answer 9

• YES - not always though

Question 10

What increases the risk of respiratory depression in patients

Answer 10

• elderly
• concomitant opioid use
• resp disease

Question 11

What sedative drug has the highest rate of cardiovascular effects

Answer 11

barbiturates

Question 12

______ is common in severe overdose

Answer 12

hypothermia

Question 13

What are the most toxic benzos?

Answer 13

alprazolam, flurazepam and temazepam

Question 14

What three drugs are usually used together that can be dangerous?

Answer 14

• benzos
• skeletal muscle relaxants
• opioids

Question 15

What is the management of benzo intoxicated patients

Answer 15

1. emergency and supportive measures (protect airways, tx coma, tx hypotension, tx hypothermia)
2. decontamination
   - activated charcoal for poly-drug overdose
   - limited utility in mono-drug overdose
   - urinary alkalinization for barbiturates (esp. phenobarbital)
3. antidotes
   - flumazenil

Question 16

What is flumazenil

Answer 16

• competitive antagonist of BZ receptor
• reverses BZD (and Z drug) induced CNS depression
• can induce BZD withdrawal
• ideal for benzo naive patients with BZ only overdose
• re-sedation is common after 1-2 hours

Question 17

What are the contraindications of flumazenil?

Answer 17

• patients that have physical dependence (withdrawal)
• patient is receiving benzo for seizure disorder
• pre-existing cardiac arrhythmia or high risk of arrhythmia
• co-ingestion of agents causing seizures
• increased intracranial pressure
• unreliable/unavailable hx

Question 18

When is flumazenil best used?

Answer 18

• pure benzo overdose

CNS depression, normal vial signs, normal electrocardiogram, otherwise normal neurologic exam

Question 19

Has long term use of BDZ associated with cumulative toxicity or organ damage?

Answer 19

• NO

Question 20

What are the predictors of long term benzo use?

Answer 20

• female gender and older age

Question 21

What are the most commonly used pharmacotherapy substitutions for benzos?

Answer 21

• longer acting benzo
• pregabalin
• carbamazepine
• melatonin
• flumazenil

Question 22

What should the taper instructions be for benzos?

Answer 22

• decrease dose by 10-25% q1-2w - slower taper may be needed for final 20%