Antidepressants

Question 1

Give the main classes of anti-depressants

Answer 1

SSRIsSNRIsTricyclic antidepressantsMonoamine oxidase inhibitors

Question 2

Give some SSRIs

Answer 2

FluoxetineCitalopramParoxetine

Question 3

Mechanism for SSRIs

Answer 3

Inhibit serotonin reuptake into nerve terminals in the synaptic cleft- very little effect on NA

Question 4

Give some common ADRs for SSRIs

Answer 4

AnorexiaNauseaDiarrhoea These normally settle within a few weeks.

Question 5

Give a drug-drug interaction of SSRIs

Answer 5

SSRI and MAOI- can cause serotonergic syndrome - autonomic disturbance, neuromuscular dysfunction and altered mental state.

Question 6

Give some SNRIs

Answer 6

VenlafaxineDuloxetine

Question 7

Mechanism for SNRIs

Answer 7

Inhibits re-uptake of both serotonin and noradrenaline- potentiates neurotransmitter activity- is dose dependentHigh dose = blocks NALow dose = blocks 5-HT

Question 8

ADRs of SNRIs

Answer 8

Anorexia Nausea Diarrhoea- settles within 2-3 weeksDry mouthHypertensionHyponatremiaSleep disturbances

Question 9

Drug-drug interactions for SNRIs?

Answer 9

MAOIs- serotonergic syndrome

Question 10

What is the first line treatment for depression?

Answer 10

SSRIsFollowed by SNRIs

Question 11

Give some tricyclic antidepressants

Answer 11

AmitryptylineImipramineClomipramineLofepramine

Question 12

What are the indications for TCAs?

Answer 12

Depression Neurological pain - amitryptyline OCD - clomipramine

Question 13

Mechanism for TCAs

Answer 13

BLock NA and 5HT reuptakeAlso binds to H1, muscarinic and alpha 1 and 2 receptors.

Question 14

ADRs for TCAs

Answer 14

Arrhythmias (NA block in heart)Dry mouth and constipation (muscarinic effects)Postural hypotension (alpha one block)Sedation (H1 block)

Question 15

Give some MAOIs

Answer 15

PhenelzineTranylcypromineIsocarboxazid

Question 16

Mechanism for MAOIs

Answer 16

Block monoamine oxidase, which metabolises monoamines. Inhibition of monoamine a gives the best antidepressant efficacy

Question 17

ADRs for MAOIs

Answer 17

HypertensionCNS stimulation (excitement adn tremor)Dry mouthBlurred vision

Question 18

Drug-drug interactions for MAOIs

Answer 18

Reduce metabolism of - barbituates- opioids- alcohol

Question 19

Pharmacokinetics of SSRIS

Answer 19

Completely absorbed by the gutLiver metabolismLong elimination half life so only need a once daily dose

Question 20

Pharmacokinetics of TCAs

Answer 20

Lipid solubleAbsorbed from the gutLong half lifeMetabolised by the liver