Psychiatric Pharmacology

Question 1

What is the Treatment Algorithm for Depression in adults?

Answer 1

Mild Depression:
1st Line = Psychotherapy +/- Antidepressant.

Moderate/ Severe Depression:
1st Line = Psychotherapy +/- Antidepressant (+ consider whether psychiatric referral or hospital admission is required).

Primary Options for Antidepressants:
- Citalopram.
- Escitalopram.
- Fluoxetine.
- Paroxetine.
- Sertraline.
- Venlafaxine.
- Desvenlafaxine.
- Duoloxetine.
- Buproprion.
- Mirtazapine.
- Vortioxetine.

2nd Line = Consider switching to an alternative antidepressant.

3rd Line = Electroconvulsive Therapy - Indicated in patients with severe depression, who have not responded to, or tolerated, antidepressant therapy.

Question 2

What is the Treatment Algorithm for Generalised Anxiety Disorder in Adults?

Answer 2

1st Line =

Question 3

What is the Mechanism of Action of Selective Serotonin Reuptake Inhibitors

Answer 3

Selective Serotonin Reuptake Inhibitors inhibit the serotonin transporter (SERT) at the presynaptic axon terminal - increasing the amount of serotonin remaining in the synaptic cleft which can stimulate the post-synaptic serotonin receptors for an extended period of time.

Question 4

List the Selective Serotonin Reuptake Inhibitors used in Clinical Practice?

Answer 4

Sertraline
Citalopram & Escitalopram
Paroxetine
Fluoxetine

Question 5

What are SSRI’s used for?

Answer 5

• SSRI’s are considered first-line treatment for the majority of patients with depression and anxiety disorders.

Question 6

What is the SSRI of choice in patients post Myocardial Infarction?

Answer 6

Sertraline is the SSRI of choice in patients post Myocardial Infarction.

Question 7

What is the SSRI of choice in children/adolescents?

Answer 7

Fluoxetine is the SSRI of choice in children and adolescents.

Question 8

Which SSRI is notorious for prolonging the QT Interval?

Answer 8

Citalopram and Escitalopram are the most notable SSRI for prolonging the QT Interval.

They are associated with dose-dependant QT interval prolongation and should not be used in those with:
- Congenital Long QT Syndrome.
- Known existing QT Interval Prolongation.
- In combination with other medicines that prolong the QT Interval.

Question 9

What is the maximum dose of citalopram in adults?

Answer 9

The maximum dose of citalopram is 40mg in adults, 20mg in those over the age of 65 years old, and in those with hepatic impairment.

Question 10

What are the Main Side Effects of Selective Serotonin Reuptake Inhibitors?

Answer 10

• Main side effects of SSRIs are gastrointestinal symptoms.
• Transient increase in anxiety/ agitation in the first few weeks of treatment.
• Hyperhydrosis.
• Insomnia.
• Dizziness.
• Loss of Libido/ Erectile Dysfunction.
• Discontinuation Syndrome.
• Increased risk of suicide in patients under the age of 30 years old in the first 2 weeks of treatment.

Question 11

Which SSRIs have the Highest Propensity for Drug Interactions?

Answer 11

Fluoxetine and Paroxetine have the highest propensity for drug interactions.

Question 12

How long should a patient continue their antidepressant if they make a good response?

Answer 12

Patients should continue their antidepressant for at least 6 months after symptom remission - as this reduces the risk of relapse.

Question 13

How do you stop an SSRI?

Answer 13

SSRIs dosage should be reduced gradually over a period of 4 weeks (this is not necessary with fluoxetine).

Question 14

Which SSRI has the highest incidence of discontinuation symptoms?

Answer 14

Paroxetine has the highest incidence of discontinuation symproms.

Question 15

Are SSRIs safe to use in Pregnancy?

Answer 15

• The BNF states that clinicians should weigh up the risk/benefit profile when deciding whether to use an SSRI in pregnancy.