SSRIs

Question 1

MoA

Answer 1

Selectively inhibit the reuptake of 5-HT from the synaptic cleft

Question 2

Commonly used SSRIs

Answer 2

Sertraline
Fluoxetine
Fluoxetine

Question 3

Which SSRI is safe in stable angina + MI

Answer 3

Sertraline

Question 4

Which antidepressant in licensed for children?

Answer 4

Fluoxetine

Question 5

Which SSRIs cause QT prolongation

Answer 5

Citalopram
Escitalopram

Question 6

Which SSRI has higher risk of withdrawal reactions?

Answer 6

Paroxetine

Question 7

Other SSRIs

Answer 7

Escitalopram
Fluvoxamine
Paroxetine

Question 8

Benefit of SSRIs over TCAs

Answer 8

SAC
Less sedating, antimuscarinic and cardiotoxic

Question 9

Side effects - SSRIs

Answer 9

GASH
GI disturbances (nausea, vomiting, diarrhoea)
Appetite or weight disturbance (gain or loss)
Serotonin syndrome
Hypersensitivity reactions (stop if reactions occur)

Question 10

Other side effects

Answer 10

Bleeding risk increased
QT interval prolongation (citalopram/escitalopram)
Seizure threshold lowered
Movement disorders + dyskinesia

Question 11

Overdose

Answer 11

N + V
Agitation
Tremor
Nystagmus
Drowsiness
Sinus tachycardia
Convulsion

Question 12

Interactions - increased plasma concentrations

Answer 12

Grapefruit juice (enzyme inhibitor)

Question 13

Interactions - increased risk of bleeding

Answer 13

NSAIDs/Aspirin (GI bleeding)
Anticoagulant
Antiplatelets e.g. warfarin

Question 14

Interactions - increased risk of QT prolongations

Answer 14

Erythromycin (macrolides)
TCAs
Sotalol
Amiodarone
Chloroquine
Mefloquine
Lithium
Quinine
Antipyschotics

Question 15

Interactions - increased risk of QT prolongation due to hypokalaemia

Answer 15

These cause hypokalaemia, which in turn can lead to QT prolongation increases risk of torsade de pointes
- Theophylline
- Beta 2 agonists
- Loop/thiazide diuretics
- Corticosteroids

Question 16

Interactions - increased risk of hyponatraemia

Answer 16

Diuretics - loop/thiazides
Desmopressin
Carbamazepine
NSAIDs

Question 17

Interactions - increased risk of serotonergic effects/serotonin syndrome

Answer 17

St. Johns wort (serotonergic antidepressant)
Amfetamines
Sumatriptan (5-HT1a agonist)
Selegiline (MAO-B inhibitor)
Tramadol (opioid that also inhibits reuptake of 5-HT + NA)
TCAs/MAOIs (serotonergic drugs)
Ondansetron (5-HT3 antagonists)

Question 18

Under 18s

Answer 18

Citalopram, escitalopram, paroxetine, sertraline, mirtazapine + venlafaxine are NOT recommended in under 18s.

ONLY fluoxetine effective in children + adolescents.

Monitor carefully for suicidal behaviour, self-harm or hostility esp @ the start.

Question 19

Cautions

Answer 19

• Epilepsy (poorly controlled/if seizures develop = discontinue)
• Cardiac disease
• Diabetes
• Susceptibility to angle-closure glaucoma
• History of mania
• Bleeding disorders

Question 20

Overdose (poisoning)

Answer 20

N + V
Agitation
Tremor
Nystagmus
Drowsiness
Sinus tachycardia

Question 21

Treatment cessation

Answer 21

GI disturbances
Headache
Anxiety
Electric shock sensation in head, neck + spine
Tinnitus
Sleep disturbances
Fatigue
Flu-like symptoms
Sweating

Palpitations + visual disturbances (less common)