SECTION 2B

Question 1

Define Generalised Anxiety Disorder

Answer 1

It is an ongoing state of excessive anxiety lacking any clear reason or focus

Question 2

List the five main classes of drugs used for the treatment of anxiety

Answer 2

Benzodiazepines 
Antidepressants - SSRI's and SNRI's 
Buspirone 
Z-Drugs 
Adrenoceptor Antagonists

Question 3

What are the useful effects of Benzodiazepines?

Answer 3

• Reduce anxiety/aggression
• Induce Sleep and sedation
• Reduce muscle tone
• Anticonvulsant

Question 4

What is the nature of the Benzodiazepines used as anxiolytics?

Answer 4

The BZDs with a long biological half-life. They may be co-administered with an SSRI during stabilisation

Question 5

Give examples of BZDs used as anxiolytics

Answer 5

Diazepam

Clonazepam

Question 6

Give details of the action of Diazepam

Answer 6

Diazepam is long acting and its actions are prolonged by its active metabolite, Nordazepam. Long duration is useful to prevent rebound anxiety.

Question 7

What is the mechanism of action of Buspirone?

Answer 7

It is a partial agonist at 5-HT1A receptors. It is thought to have the anxiolytic effect through the somatodendritic 5-HT1A which function as inhibitory autoreceptors.

Question 8

What is the proposed mechanism by which anxiolytic drugs affecting 5-HT transmission have their action?

Answer 8

Buspirone and SSRIs thought to induce desensitization of somatodendritic 5-HT1A autoreceptors resulting in heightened 5-HT release.

Question 9

What is the mechanism of action of Clonidine?

Answer 9

It is an alpha 2 adrenoceptor agonist. Activation of this autoreceptor on presynaptic NA neurons decreases NA release. It is an effective anxiolytic

Question 10

How is propranolol a useful anxiolytic?

Answer 10

It is a non-selective Beta adrenoceptor blocker. These are found usually postsynaptically. These drugs are mainly useful for competition nerves/ situational anxiety

Question 11

Name a Z-drug and its mechanism of action

Answer 11

Zolpidem. It acts at the BZD site on the GABAa receptor as a positive allosteric modulator.
Specifically acting at receptors with the alpha 1 subunit.

Question 12

What are the main disadvantages of Benzodiazepines?

Answer 12

• Tolerance - higher doses required to achieve the same affect
• Withdrawal symptoms (dependence) - rebound heightened anxiety following immediate cessation
• Enhance depressant effects of other drugs (e.g. alcohol) can be fatal

Question 13

Where is the binding location for Benzodiazepines on the GABAa receptor?

Answer 13

At the interface of the alpha and gamma subunits. They only act on receptors containing gamma 2 and alpha 1, 2, 3, or 5 specifically