Antidepressants Flashcards
Phenelzine
Non-selective, irreversible MAOI
Inc. synaptic conc. of Ad, NA, DA and 5HT
Precautions: Rizatriptan & Sumatriptan use, angina, epilepsy, bipolar, serotonin toxicity.
ADEs: orthostatic hypotension, sleep disturbances, weight gain & anticholinergic effects.
Counselling: last dose
Tranylcypromine
Non-selective, irreversible MAOI
Inc. synaptic conc. of Ad, NA, DA and 5HT
Precautions: Rizatriptan & Sumatriptan use, angina, epilepsy, bipolar, serotonin toxicity.
ADEs: orthostatic hypotension, sleep disturbances, weight gain & anticholinergic effects.
Counselling: last dose
Citalopram
SSRI - Selectively inhibit presynaptic reuptake of 5HT.
IND: Major depression, anxiety disorders, premenstrual dysphoric disorder & bulimia.
PREC: Bipolar, high bleeding risk, high hyponatraemia risk & serotonin toxicity. *may prolong QT interval >40mg. *CYP2C19
ADEs: agitation, insomnia, sexual dysfunction, weight changes.
Escitalopram
SSRI - Selectively inhibit presynaptic reuptake of 5HT.
IND: Major depression, anxiety disorders, social phobias & OCD.
PREC: Bipolar, high bleeding risk, high hyponatraemia risk & serotonin toxicity. *may prolong QT interval *CYP2C19
ADEs: agitation, insomnia, sexual dysfunction, weight changes.
Fluoxetine
SSRI - Selectively inhibit presynaptic reuptake of 5HT.
IND: Major depression, premenstrual syndrome & OCD.
PREC: Bipolar, high bleeding risk, high hyponatraemia risk & serotonin toxicity. *may prolong QT interval *CYP2C19
ADEs: agitation, insomnia, sexual dysfunction, weight changes.
*long half life (up to 16 days)
Fluvoxamine
SSRI - Selectively inhibit presynaptic reuptake of 5HT.
IND: Major depression & OCD.
PREC: Bipolar, high bleeding risk, high hyponatraemia risk & serotonin toxicity. Cisapride use contraindicated.
ADEs: agitation, insomnia, sexual dysfunction, weight changes.
Take with food.
Paroxetine
SSRI - Selectively inhibit presynaptic reuptake of 5HT.
IND: Major depression, anxiety disorders, social phobias, PTSD & OCD.
PREC: Bipolar, high bleeding risk, high hyponatraemia risk & serotonin toxicity. Renal insufficiency.
ADEs: agitation, insomnia, sexual dysfunction, weight changes.
Take with food.
Sertraline
SSRI - Selectively inhibit presynaptic reuptake of 5HT.
IND: Major depression, anxiety disorders, social phobias & OCD.
PREC: Bipolar, high bleeding risk, high hyponatraemia risk & serotonin toxicity.
ADEs: agitation, insomnia, sexual dysfunction, weight changes.
Mechanism of action of TCAs
Inhibit the reuptake of 5HT and NA into presynaptic terminals.
Precautions of TCA use.
Prostatic hypertrophy - may precipitate urinary retention
Hyperthyroidism - may have enhanced response to TCAs
Epilepsy - TCAs may increase risk of seizures (so may depression)
Coronary heart disease - TCAs may precipitate angina
May prolong Q-T interval
Orthostatic hypotension may be exacerbated.
High abuse potential.
Common ADEs of TCAs
Sedation Dry mouth Blurred vision Weight gain Orthostatic hypotension Reduced GI motility
Cardiac ADEs of TCAs:
Slowed cardiac conduction
T-wave inversion
Sinus tachycardia
Prolonged QT interval
Counselling points for TCAs
Side effects such as blurred vision, dry mouth and drowsiness that should resolve within 7 days
Take at night to reduce daytime drowsiness
Orthostatic hypotension
Avoid driving or operating heavy machinery if affected
Don’t stop taking this medicine abruptly.
Alternate indications for amitriptyline:
Nocturnal enuresis
Adjuvant in pain management
Migraine prophylaxis
Urinary urge incontinence
Indications for clomipramine:
Major depression
OCD (drug of choice)
Cataplexy associated with narcolepsy
MOA of SNRIs:
Inhibit 5HT and NA reuptake.
Precautions for SNRIs:
Bipolar disorder Epilepsy Risk factors for angle closure glaucoma High risk of bleeding Tx with drugs that may cause hyponatraemia
ADEs of SNRIs:
Cardiac: May cause tachycardia, palpitations, hypertension and orthostatic hypotension.
Serotonin toxicity
Common: Nausea, dry mouth, constipation, sexual dysfunction.
Counselling points for SNRIs:
Be careful driving or operating machinery until you know how this medication affects you.
Don’t stop taking this medicine abruptly.
MOA of Agomelatine:
Unclear, Melatonin receptor agonist (M1 and M2) and 5HT receptor antagonist.
Precautions for Agomelatine:
Combination with potent CYP1A2 inhibitors - may increase agomelatine concentration.
Bipolar disorder
Hepatic impairment - increases concentration
ADEs of Agomelatine:
Dizziness, abdominal pain
Increased aminotransferases
Counselling points for Agomelatine:
This medicine may make you feel dizzy or sleepy, do not drive or operate machinery if affected.
Stop taking this medicine and tell your Dr if you develop dark urine, pale stools or yellow skin or eyes.
MOA of mirtazapine:
Tetracyclic antidepressant.
Postsynaptic blockade of 5HT receptors and presynaptic blockade of alpha inhibitory auto receptors.
Also potent H1 antagonist = sedation.
Precautions for Mirtazapine use:
Tx with (or within 14 days of) MAOIs.
Epilepsy
Bipolar disorder
Phenylketonuria - soltabs contain aspartame which is metabolised to phenylalanine.
ADEs of Mirtazapine:
Increased appetite
Weight gain
Sedation
Peripheral oedema
MOA of Moclobemide:
Competitively and reversibly inhibits MAO.
Relatively selective for MAO-A.
Synaptic concentrations of 5HT, NA and DA are increased.
Precautions for Moclobemide use:
Bipolar disorder
Serotonin toxicity
ADEs of Moclobemide:
Dry mouth
constipation
Restlessness
Insomnia
Counselling points for Moclobemide:
Best taken with food.
Don’t take after noon, may cause insomnia.
Low tyramine diet is not usually required below max dose (600mg daily).
MOA of Reboxetine:
Inhibits NA reuptake.
Weakly inhibits 5HT reuptake.
Precautions for Reboxetine use:
Tx with MAOIs - contraindicated
Risk of angle closure glaucoma
Epilepsy
Bipolar disorder
Cardiovascular disease - may cause orthostatic hypotension and tachycardia
Bladder outlet obstruction - may exacerbate
ADEs of Reboxetine:
Urinary retention
Dysuria
Decreased appetite
Impotence
