Hypnotics and Sedatives - Benzodiazepines

Question 1

There are 3 core drugs we need to know that are classed as benzodiazepines. Which of the following is NOT a benzodiazepine we need to know?

1 - Diazepam
2 - Lorazepam
3 - Chlordiazepoxide
4 - Zopiclone

Answer 1

4 - Zopiclone

Question 2

Benzodiazepine, are drugs which generally act as a neural depressant. They can exerts anxiolytic (anti-anxiety), sedative, muscle- relaxant, anticonvulsant and amnestic effects. What is the mechanism of action of this drug?

1 - agonist of D2 dopamine receptors
2 - antagonist of D2 dopamine receptors
3 - binds GABA-a receptors increases chloride influx
4 - binds GABA-b receptors decreasing chloride influx

Answer 2

3 - binds GABA-a receptors, increases chloride influx

• bind to the z site between the alpha-1 and gamma-2 subunits of GABA- A receptors changing shape of receptors and allowing more GABA to bind and more Cl- to flow into the cell

Question 3

In addition to benzodiazepine, which other compound binds with GABA receptors acting as a form of sedation?

1 - nicotine
2 - cannabis
3 - ethanol

Answer 3

4 - ethanol

• acts like benzodiazepine and accentuates GABA binding
• alcohol also acts as antagonist for glutamate, so when alcohol is stopped patients have withdrawal effects
• benzodiazepine can be given for withdrawal in a controlled manner

Question 4

Benzodiazepine, has a number of indications. All of the following are indications for the use of benzodiazepines. Which 2 of the following are benzodiazepines the first line in management?

1 - palliative care
2 - insomnia
3 - alcohol withdrawal
4 - status epilepticus
5 - interventional procedures for rapid tranquillisation
6 - anxiety (disabling/distressing)

Answer 4

3 - alcohol withdrawal

4 - status epilepticus
- seizure lasting >5mins

Question 5

Due to the mechanism of action of benzodiazepines, which of the following is NOT an adverse event of benzodiazepines?

1 - drowsiness
2 - coma
3 - seizure
4 - sedation

Answer 5

3 - seizure

Question 6

Which of the following systems do benzodiazepines have a depressive effect on?

1 - cardiorespiratory
2 - vomit reflex
3 - respiratory drive
4 - involuntary motor function

Answer 6

3 - respiratory drive

• depress central respiratory drive and chemoreceptor responsiveness to hypercapnia (high CO2)
• can lead to airway obstruction and death

Question 7

Should a patient taking benzodiazepines just stop taking the drug or be slowly be tapered down?

Answer 7

• slowly tapered down
• patients can become dependent and have withdrawal effects like alcohol if stopped too quickly

Question 8

Which group of patients are particularly susceptible to benzodiazepines and should therefore be prescribed lower doses?

1 - older patients
2 - immunocompromised
3 - younger patients
4 - caucasians

Answer 8

1 - older patients

Question 8

Patients with 2 of the following should not be prescribed benzodiazepines due to the potential adverse events?

1 - dementia
2 - respiratory impairment
3 - neuromuscular disease
4 - cardiovascular disease

Answer 8

2 - respiratory impairment
3 - neuromuscular disease

Question 9

Why should patients with liver disease generally not be prescribed benzodiazepines?

1 - excreted in hepatobiliary system
2 - excreted in bile
3 - metabolised by ALT
4 - metabolised by CP450

Answer 9

4 - metabolised by CP450

• conjugated with glucuronide (phase II), and excreted almost entirely in the urine
• can make hepatic encephalopathy worse

Question 10

DO benzodiazepines have a additive or subtractive effect on sedating drugs like alcohol and opiods?

Answer 10

• additive

Question 11

There are important interactions between benzodiazepines and specific drugs such as

• amiodarone (K+ channel blocker)
• macrolids (antibiotic)
• diltiazem (Ca2+ channel blocker)
• fluconazole (anti-fungal)

What effect can all of these drugs have on benzodiazepines?

1 - reduce the effect of benzodiazepines
2 - increase the effect of benzodiazepines
3 - increase toxicity
4 - damage kidneys

Answer 11

2 - increase the effect of benzodiazepines

• all 4 drugs inhibit CP450
• no CP450 means longer half life of benzodiazepines

Question 12

For seizures a long acting benzodiazepines is preferred, such as Diazepam (D) or Lorazepam (L) given IV. What are the dosages of these drugs generally prescribed?

1 - D = 4mg and L = 10mg
2 - D and L = 4mg
3 - D and L =10mg
4 - D = 10mg and L = 4mg

Answer 12

4 - D = 10mg and L = 4mg

Question 13

Patients should be closely monitored following the prescription of benzodiazepines. What is the generally the maximum time period benzodiazepines should be prescribed for?

1 - 4 weeks
2 - 3 weeks
3 - 2 weeks
4 - 1 week

Answer 13

1 - 4 weeks

• BUT dosage should be reduced after 2 weeks