Benzodiazepenes et al.

Question 1

Classifications: Sedative vs Hypnotic vs Anxiolytic

Answer 1

Sedative: Calm down, treat agitation

Hypnotic: Induce sleep

Anxiolytic: Reduce anxiety
physical, emotional, cognitive

*Drugs can fall into 1, 2 or all 3 categories

Question 2

Sedatives

Answer 2

Calm down individual and treat agitation

Alcohol – the oldest known sedative

1900s – use of barbiturates–alter GABA receptors
*Narrow Tx Window

1960 – creation of Librium, first benzo

Question 3

Benzodiazepenes: Therapeutic Uses

Answer 3

Sedative-hypnotic

Anxiolytic

• Panic disorder
• GAD

Acute mania

Anticonvulsant

Muscle relaxants

Alcohol withdrawal

PMS

Question 4

Benzos vs SSRI

Answer 4

Benzos good for immediate sx relief
*faster than SSRIs for panic

Best used for exacerbations of anxiety

• short term vs continuous use
• useful initial adjunct until other meds reach tx level

Long-acting, low potency preferred (e.g Clonazepam)

Question 5

Benzodiazepines: mechanism of action

Answer 5

Binds to GABA-a receptors

Open Cl- channels
*hyperpolarization: decreases neural firing rate

Effect is sedative, hypnotic, muscle relaxant

Question 6

Commonly prescribed Benzodiazepines

In increasing order of half-life

Answer 6

Alprazolam: Xanax – most popular, shortest half-life
6-12 hours
*high rate of overdose

Lorazepam: Ativan 10-20

Clonazepam: Klonopin 18-50

Diazepam: Valium 20-100
*active metabolite can last 36-200 hours

Question 7

Benzo: Pharmocokinetics

Answer 7

Lipid-soluble, easily crosses blood-brain-barrier

Rapid onset of action

Question 8

Benzos: Aversive effects

Answer 8

Benzos have fewer side effects than other psychotropics, but not insignificant:

*Sedation

• CNS depression
• Worse if combine with EtOH
• Bx Disinhibition
• Psychomotor and Cognitive Impairment
• Linked with Alzheimer’s
• Potential for addiction

Question 9

Benzodiazepene Interactions

Answer 9

Antibiotics

Antiretrovirals

Antabuse

Warfarin (blood thinner)

Citrus Juice

Question 10

Benzos: Paradoxical Effect

Answer 10

Increased hostility and aggression

Increased anxiety and perceptual disorders

Sx range: 
talkativeness
excitement
aggression 
antisocial acts

~5% risk

Question 11

Barbituates

Answer 11

Barbiturates such as phenobarbital were long used as anxiolytics and hypnotics

Mostly replaced by benzos (lower risk /lower sfx)

*Though still used today as anticonvulsants, para-operative sedatives, and analgesics

Question 12

Antihistamines

e.g. Bendadryl, Atarax

Answer 12

Non-addicting tx of anxiety and insomnia

Some anticholinergic effects

Question 13

Common Anticholinergic Side Effects

Answer 13

Blurred vision

Constipation

Decreased sweating

Dizziness

Dry mouth

Difficulty urinating and/or kidney failure

Question 14

Beta-Blockers

e.g. Propranolol

Answer 14

Beta blockers treat physiological components of anxiety:

Tachycardia

Palpitations

Tremor

Sweating

Helpful for performance anxiety*

Question 15

Benzo tx Duration

Answer 15

● 80% < 4 months

● 15% > 12 months

● Women 2x more likely prescribed

● Used in more than 40% of panic dx patients

Question 16

Less Common Benzos

Answer 16

Shortest half-life:
Versed 0.5 -1.0
Halcion 0.75- 2

1s benzo 1959: Librium

Others:
Tranxene
Rosom
Dalmane
Serax
Doral
Restoril

Question 17

Benzos adverse effects: Psychomotor and Cognitive Impairment

Answer 17

Loss of coordination, decreased attention, impaired reaction time
*caution driving

Potential diminished visual-spatial ability and psychomotor performance

Ataxia, confusion

Question 18

Benzos: Paradoxical Effect prediction and treatment

Answer 18

No clear predictive factors, though alcohol consistently increases risk

Potential higher risk for those with “pre-existing impulse control”

Adjustment of the dose (up or down) usually attenuates the impulses

Question 19

Beta blockers: Contraindications

Answer 19

Do Not Prescribe if presence of:

Asthma

Diabetes

CHF

*General consideration for beta blockers: regular monitoring of BP, pulse

Question 20

Baribituates: Risks

e.g. phenobarbitol

Answer 20

Narrow therapeutic range
* Fatal respiratory depression

Rare risk of Stevens-Johnsons Syndrome

Question 21

Beta Blockers: Advantages

e.g. Propranolol

Answer 21

No CNS depression

Non-addicting

No drowsiness