Antidepressants Flashcards
State the duration of therapy for antidepressant therapy?
Acute: 8-12 weeks
Maintenance: 6-24 months or longer
What are the monoamines?
dopamine, norepinephrine, serotonin
What is the monoamine hypothesis of depression?
Depression is caused by a functional insufficiency of monoamine neurotransmitters
How do antidepressants work?
Antidepressants works by restoring homeostatic equilibrium of the NT system, by increasing the availability of these NTs - as their names suggest, they target the vesicles and recycler molecules in the synapse, preventing the reabsorption of NT into the axon terminal, which results in more NT in the synaptic cleft for longer, therefore more chances for the NT to bind.
SSRIs MOA
block the reuptake of serotonin
SNRIs MOA
block the reuptake of serotonin and norepinephrine
NDRIs MOA
block the reupatake of norepinephrine and dopamine
also used for smoking cessation
SSRI common drug names
Citalopram (Celexa)
Escitalopram (Cipralex)
Sertraline (Zoloft)
Fluoxetine (Prozac)
SNRI common drug names
Venlafaxine (Effexor)
Desvenlafaxine (Pristiq)
Duloxetine (Cymbalta)
NDRI common drug names
Bupropion (Wellbutrin)
SSRI side effects
Insomnia (take AM) , sedation (take PM) , headache.
Nausea, vomiting (goes away after you get used to new drug), diarrhea, weight gain
Sexual dysfinction
Hyponatremia
Serotonin syndrome (in combination)
SNRI side effects
same as SSRI
PLUS increased BP and increased HR
NDRI side effects
Seizure risk (dose related) insomnia,, agitation, headache
Stimulating (not ideal for folks with anxiety)
NO weight gain of sexual dysfunction, or serotonin syndrome
NDRI contraindications
Bulimia, anorexia, seizure disorder, abrupt withdrawal from alc or benzos
what is serotonin syndrome?
Serotonin syndrome is usually the result of the combination of two or more drugs that enhance the transmission of serotonin, resulting in excessive serotonergic activity in the CNS. It can happen after a single serotonergic drug or an increased dose (and includes OTC and NHPs that increase serotonin) Fast onset
symptoms of serotonin syndrome
- Mental/behavioural: anxiety, agitation, confusion, seizures, coma
- Muscle tone: tremor, shivering, rigid, hyperreflexia
- Autonomic: hypertension, fever, tachycardia, vomiting, diaphoresis (excess sweating) diarrhea,
risks of antidepressant withdrawal syndrome
o Antidepressant use > 5 weeks
o High dose
o Agents with short half lives (paroxetine, venlafaxine) are worse than agents that get removed slowly
o Previous hx of antidepressant withdrawls
symptoms of antidepressant withdrawal syndrome
FINISH
Flu
Insomnia
Nausea
Imbalance
Sensory disturbance
Hyperactivity
Why should antidepressants be tapered off of before discontinuation/switching of agents.
to avoid withdrawal & the unpleasant and dangerous symptoms
What should you monitor the infant for in ALL antidepressants
sedation, irritability, poor feeding/weight gain
SSRI potential risks in pregnancy
- NAS (neonatal abstinence syndrome)
- PPHN (Persistent Pulmonary Hypertension of the newborn)
what are the potential risks of paroxetine in pregnancy
conflicting evidence about potential correlation to cardiac anomalies
what is the most commonly used class of anti-depressant in pregnancy
SSRI
What is PPHN (incl symptoms)
Persistent Pulmonary Hypertension of the newborn:
maintained high vascular resistance to the lungs = poor oxygenation -
What is NAS
Neonatal abstinence syndrome, 30% of infants, resolves in 2 weeks with supportive care (irritability, tachypnea, temp instability) not associated with an increased risk of mortality or neurodevelopmental problems
SNRI risks in pregnancy
Inconsistent data linking bupropion explore to cardiac anomalies, overall evidence does not suggest an increased rate of congenital malformation with first trimester exposure
What have case reports associated with NDRI in bf?
2 case reports of seizures, although adverse effects are very rare
What clinical tip should you rememeber re: long hospital stays
Going through SSRI withdrawal while also in labour during a longer hospital stay is not fun!! remember your meds in your hospital bag
