A/30. Selective serotonin and/or norepinephrine reuptake inhibitors.

Question 1

Drugs need to know in this topic

Answer 1

fluoxetine

sertraline

(es)citalopram

venlafaxine

duloxetine

reboxetine

Question 2

Selective serotonin reuptake inhibitors (SSRI’s)
Mechanism of action

Answer 2

• Selective inhibition of 5-HT reuptake; allosterically inhibit the transporter, binding at a site other than that of serotonin
• Minimal inhibitory effects on NE transporter, cholinergic, and adrenergic receptors

Question 3

Fluoxetine

(ES)Citalopram

Sertraline

Answer 3

Oral

1. Major depressive disorders
2. Anxiety disorders (GAD – generalized anxiety disorder)
3. Obsessive compulsive disorder (OCD)
4. Post-traumatic stress disorder (PTSD)
5. Premenopausal dysphoric disorder (PMDD)
6. Panic disorders
7. Bulimia

• *Adverse effects:**
  8. Anxiety, agitation*
  9. Sleep disorders
  10. Bruxism
  11. Sexual dysfunction** (mediated by 5-HT2A receptors) – libido↓, anorgasmia, erectile dysfunction
  12. Weight gain
  13. SIADH
  14. Withdrawal syndrome → flu-like symptoms, dizziness, anxiety, tremor, palpitations

Drug interactions:
3. Inhibition of P450 enzymes → increased levels of TCA’s, benzodiazepines, warfarin
4. Serotonin syndrome (with MAO inhibitors, TCA’s, meperidine) → muscle rigidity, myoclonus, hyperthermia, CV instability, ANS instability, seizures
*Citalopram is the agent least frequently associated with drug-drug interactions

Question 4

Serotonin-norepinephrine reuptake inhibitors (SNRI’s)
Mechanism of action

Answer 4

1. Inhibit the reuptake transporters responsible for terminating the synaptic actions of both NE and 5-HT in the CNS
2. No effect on cholinergic and adrenergic receptors

Question 5

Venlafaxine

Duloxetine

Reboxetine

Answer 5

Oral

Inhibitors of cytochrome P450 enzymes

1. Major depressive disorders
2. Fibromyalgia
3. Neuropathic pain disorders
4. Diabetic neuropathy (duloxetine)
5. Panic disorder, OCD, PTSD (venlafaxine)