Antidepressants Flashcards
Name 5 SSRIs
citalopram escitalopram fluvoxamine fluoxetine (adolescents) sertraline (post MI) paroxetine
How are SSRIs metabolised?
cytochrome p450 enzyme
and enzyme inhibitors
Which SSRIs are highest and lowest in breast milk?
highest with fluoxetine and citalopram,
lowest with sertraline and paroxetine
Which SSRIs particularly prolong QTc interval?
citalopram and escitalopram
What are the symptoms of discontinuation syndrome?
Which SSRIs are most likely to give it?
shivering, anxiety, “electric shock”, headache and nausea
paroxetine most likely - short half life
fluoxetine least likely - long half life
What are some side effects of SSRIs?
- GIT: nausea, vomiting, diarrhoea
- agitation, insomnia dizziness, headaches
- sexual dysfunction (esp paroxetine)
- hyponatremia in elderly
- bleeding (due to platelet 5-HT depletion)
- increased thoughts of harm in <26yo
SSRI clinical uses?
Depression, panic disorder, generalised anxiety disorders, obsessive-compulsive disorder, bulimia nervosa, PTSD, premature ejaculation, premenstrual dysphoric syndrome or hot flushes in women with breast cancer
What are the signs of serotonin syndrome?
3As:
Activity: myoclonus, nystagmus, HYPERreflexia, hypertonia, tremor, seizure
Autonomic: hyperthermia, diaphoresis, diarrhoea
Agitation: agitation, confusion, mood change, headache
Antidote to serotonin syndrome?
cyproheptadine
Name 3 SNRIs
Venlafaxine, Desvenlafaxine and Duloxetine
serotonin-norepinephrine reuptake inhibitors
Which SNRI should you avoid with alcohol?
duloxetine
liver disease
Clinical uses of SNRIs?
Depression, generalised anxiety disorders, diabetic neuropathy.
Venlafaxine: OCD, PTSD, panic disorder, anxiety disorder
SNRI side effects are similar to SSRIs, what is the most common SNRI side effects?
Raise in BP
Name 6 TCAs and their sedative effect?
More sedating:
- Amitriptyline,
- Clomipramine,
- Dosulepin (dothiepin)
Less sedating:
- Imipramine,
- Lofepramine
- Nortriptyline.
MOA of TCAs?
potentiate noradrenaline and serotonin by blocking their reuptake
Clinical use of TCAs?
major depression, OCD (clomipramine), peripheral neuropathy, chronic pain, migraine prophylaxis
Side effects of TCAs?
a. Antimuscarinic effects: Blurring vision, dry mouth, retention of urine and constipation.
b. Anti-histaminic action: Weight gain, sedation etc.
c. Alpha1 adrenergic action: Dizziness, orthostatic hypotension etc.
d. Blockage of voltage-sensitive sodium channels (heart and brain): overdose can lead to coma, seizure, cardiac arrhythmias, QTc lengthening, cardiac arrest and death.
(Cardiac is the main reason why they are no longer used as 1st line treatment of depression.) (Sodium bicarb in overdose for arrhythmias)
Mnemonic to remember MAOI drugs?
MAO Takes Pride In Shanghai
Name 5 MAOIs?
Moclobemide (reversible) Tranylcypromine, Phenelzine, Isocarboxazid and Selegiline (all irreversible)
(Mao takes prides in Shanghai)
Clinical use of MAOIs?
severe depression, treatment resistant depression and atypical depression
What is a particular adverse effect of MAOIs? Cause?
Hypertensive crisis
- tyramine ingestion in food
- indirect sympathomimetics (phenylephrine)
What foods contain tyramine?
Wine, aged cheese, yeast extracts, game, pickled herring,
What is /are some drugs contraindicated with MAOIs?
SSRIs, TCAs (give 2 week washout period)
St Johns wort, meperidine, dextromethorphan
Medically avoid in: Delirium, Pheochromocytoma, Hyperthyroidism, CVD, elderly postural hypotension.
What is another use of MAOI selegiline and why?
it is more selective towards MOA-B.
MAO-B degrades dopamine, selegiline is used with levodopa to prevent its degradation and prolong its effects in Parkinson’s
What is mirtazapine mechanism and side effects?
Increases NA by blocking negative feedback on alpha 2 receptors
Sedation, increase appetite, weight gain, dry mouth
What class is trazodone and what are its uses?
Tetracyclic (acts on serotonin)
Primarily for insomnia (higher doses for anti depressive)
SE: priapism, etc
“traZZZoBONER”
What is an antidepressants used for smoking cessation?
Varenicline
nicotinic ACh partial agonist
(SE: sleep disturbance)
Can TCAs be used in pregnancy / breastfeeding?
Best avoided but generally TCAs are considered safe
