Antidepressants Flashcards
What are the 3 major classes of antidepressants?
- Tricyclic & related antidepressants (TCAs) - increases 5HT & NA levels
- Selective serotonin reuptake inhibitors (SSRIs) - increases 5HT only
- Monoamine oxidase inhibitors - Increases 5HT, NA & Dop
5HT - Serotonin
What’s another class of Antidepressants?
SNRIs - Venlafaxine, Duloxetine.
What are some examples of Tricyclic antidepressants?
- Amitriptyline & Nortriptyline (used for neuropathic pain)
- Clomipramine
- Dosulepin
- Imipramine (most antimuscarinic effects)
- Lofepramine (liver toxic)
Examples of Tetracyclic antidepressants?
Trazodone & Manserin
Examples of Selective Serotonin reuptake inhibitors (SSRIs)?
- Citalopram
- Escitalopram
- Fluoxetine (licensed in children)
- Paroxetine (high withdrawal symptoms, so have to withdraw over a long period of time)
- Sertraline (safe in unstable angina & M.I)
Examples of Monoamine oxidase inhibitors (MAOIs)?
There are irreversible MAOIs n reversible MAOIS.
Irreversible:
- Phenelzine
- Isocarboxazid
- Tranylcypromine (hypertensive crises risk)
Reversible:
- Moclobemide (no washout period - licensed for social anxiety disorder)
What is a washout period?
The time it takes for it to get washed out of your system
What is the indication for antidepressants?
Effective for moderate to severe depression
Not really used for mild depression. Non-medical therapy are normally used for mild like psychological therapy.
How long does it take for antidepressants to take effect?
2 weeks
After 4 weeks, if there’s no effect, doctors can change the medication.
What’s a sign that the antidepressants are working?
Improvement in sleep
What is a side effect of antidepressants?
Increased potential for agitation, anxiety and suicidal thoughts (paradoxical effects), during the first few weeks of treatment.
Is one antidepressant more effective than another?
No, they have similar efficacy but different side effects.
Which antidepressant is 1st class and why?
SSRIs
Because they are better tolerated and safer in overdose than others.
There’s less sedating.
And fewer antimuscarinic & cardiotoxic effects.
And sertraline is safe in patients with unstable angina or who have recently had a MI.
Why aren’t Tricyclic antidepressants and MAOIs first choice?
Tricyclic:
- Toxicity in overdosage is a problem
- More sedating
- More antimuscarinic & cardiotoxic side effects
MAOIs:
- Dangerous interaction with some foods & drugs
- It’s reserved for use by specialist
Examples of enzyme inhibitors?
- Sodium valproate
- Isoniazid
- Cimetidine
- Ketoconazole
- Fluconazole
- Alcohol (binge drinking)
- Chloramphenicol
- Erythromycin
- Sulfonamides
- Ciprofloxacin
- Omeprazole
- Metronidazole
- Grapefruit juice