Week 10 - Antidepressant Drugs

Question 1

What are the Monoamines?

Answer 1

Noradrenaline
Serotonin
Dopamine

Question 2

How is Depression linked to Monoamines?

Answer 2

Depression = associated w deficiency of monoamines

Question 3

What are Tricyclic Anti-depressants (TCAs)? what do they do? eg?

Answer 3

Blocks the reuptake of NA and Serotonin 5-HT
Stops neuron from taking neurotransmitters back up

Also antagonise Muscarinic, alpha-1 and H1 receptors

eg Desipramine

Question 4

What are side effects of TCAs?

Answer 4

Cardiac toxicity -> arrhythmias, ventricular fibrillation

Question 5

What are Selective Serotonin Reuptake Inhibitors (SSRIs)? what do they do? eg?

Answer 5

-> Selectively block the reuptake of 5-HT

• preferred to TCAs bc much better tolerated safety profile

eg Fluoxetine

Question 6

What are side effects of SSRIs?

Answer 6

• disturbed sleep
• lower sex drive
• nausea and diarrhoea
• can cause initial increase in anxiety

Question 7

What are acute increases in anxiety attributed to?

Answer 7

enhanced 5-HT stimulation of 5HT2A receptors before they undergo downregulation

Question 8

What are Serotonin and Noradrenaline Reuptake Inhibitors (SNRIs)? what do they do? eg?

Answer 8

• similar MOA to TCAs
• block reuptake of both NA and 5-HT

eg Venlafaxine

Question 9

What are Noradrenaline Reuptake Inhibitors (NRIs)? what do they do? eg?

Answer 9

• Block reuptake of NA

eg Reboxetine

Question 10

What are Monoamine Oxidase (MAO) isoforms?

Answer 10

-> enzymes that metabolise intracellular NA, 5-HT and Dopamine (DA)

Inhibitors can be reversible and irreversible

Question 11

What do MAOa and MAOb metabolise?

Answer 11

Question 12

What are Irreversible Monoamine Oxidase (MAO) Inhibitors? What do they do? eg?

Answer 12

= Irreversible and non-selective MAOa/b inhibitor
- will cause an increase in NA, 5-HT, and DA

eg Tranylcypromine

Question 13

What are some precautions to take with Irreversible MAO inhibitors?

Answer 13

Avoid foods rich in tyramine bc tyramine can cause hypertensive problems

Question 14

What are Reversible Monoamine Oxidase (MAO) Inhibitors? What do they do? eg?

Answer 14

= Reversible and selective to MAOa

eg Moclobemide

Question 15

What are Serotonin Antagonist and Reuptake Inhibitors (SARIs) ? What do they do? eg?

Answer 15

• Block 5-HT reuptake and antagonise 5-HT2A receptors simultaneously
• less incidence of acute anxiety compared to SSRIs // less potent than TCAs and SSRIs

eg Trazodone

Question 16

What are Alpha2 Receptor Antagonists? What do they do? eg?

Answer 16

• Antogonise pre-synaptic a2 adrenoreceptors
• result in enhanced release of both NA and 5-HT

eg Mianserin

Question 17

Unipolar vs Bipolar

Answer 17

Unipolar = one direction -> continuously depressed
Bipolar = fluctuation of mood

Question 18

What are signs and symptoms of Bipolar Disorders?

Answer 18

Question 19

How does Lithium help with Bipolar disorders? MoA?

Answer 19

• can be used for prophylaxis of manic and depressive episodes and for acute mania
• lacks effectiveness where mood is rapidly recycling

MoA:
- unclear
- lodges in voltage-dependent Na+ channels and not pumped out
- accumulates in excitable tissue -> and maybe inhibits dopamine release, increase serotonin release & disrupts cell signalling

Question 20

Side effects of Lithium treatment?

Answer 20

• nephrotoxic
• can induce diabetes insipidus
• can be associated w hypothyroidism development