NONCYCLIC ANTIDEPRESSANTS

o Fluoxetine

o Sertraline

o Citalopram

o Escitalopram

o Paroxetine

o Fluvoxamine

SELECTIVE SEROTONIN REUPTAKE INHIBITORS (SSRI)

o Venlafaxine

o Desvenlafaxine

o Duloxetine

SEROTONIN-NOREPINEPHRINE REUPTAKE INHIBITORS

Bupropion

NOREPINEPHRINE-DOPAMINE REUPTAKE INHIBITOR

• Causes CNS depression

• SSRIs may interact with each other (potentiating the action of serotonin), with chronic use of MAO inhibitor or with dextromethorphan may produce serotonin syndrome

MECHANISM OF TOXICITY

SNRIs

are potent serotonin and noradrenaline reuptake inhibitors with rate dependent sodium channel blocking activity

serotonin syndrome

• Using NDRI while taking MAO inhibitors may cause

TOXIC DOSE SSRI:

o Citalopram:

o Escitalopram:

>600 mg.

>300 mg

• SNRI (Venlafaxine):

o Ingestion of >_ g: seizures, serotonergic toxidrome.

o Ingestion of >_ g: 50% seizure risk.

o Ingestion of >_ g: cardiotoxicity.

>2 g:

>5 g:

>8 g:

NDRI (Bupropion):

o >2.5 g: seizures.

o >6 g: serious toxicity.

o >9 g: fatalities.

>2.5 g:

>6 g:

>9 g:

Ataxia, sedation, coma, respiratory depression (with alcohol), rest- lessness, anxiety, agitation, tremors, seizures

CNS:

(NDRIs, SNRIs).

Hypertension, sinus tachycardia

(SSRIs).

Hypotension, sinus bradycardia

(Citalopram).

QT prolongation, torsade de pointes

• Neuromuscular hyperactivity

• Autonomic instability

• Mental status change

Serotonin Syndrome:

Benzodiazepines

for mild serotonin syndrome, to control tremor and agitation

Severe serotonin syndrome with hyperthermia

requires hospitalization and aggressive cooling measures which often include neuromuscular paralysis and endotracheal intubation

hand tremors

patients who take antidepressant drugs have

• Cyproheptadine 12 mg orally or by nasogastric tube, followed by 4 mg every hour for 3-4 doses

• Chlorpromazine 25-50 mg IV

SPECIFIC ANTIDOTE (SEROTONIN SYNDROME): •