SSRI (selective serotonin reuptake inhibitor)

 SSRI (selective serotonin reuptake inhibitor) 血清素再吸收阻斷劑

SUBSTANCE

 

-          Newer and safer antidepressant compared to TCA [1].

-          Lower ADR than TCA.

 

 

Common name or Trade name 

 

-          Fluvoxamine、Paroxetine、Sertraline、Citalopram、Escitalopram、Fluoxetine。

 

 

Involving SYSTEM

 

-          Serotonin,  about 98% in extra-CNS [2]。

-          A long elimination half-life, with sustained biological activity due to active metabolites

-          In overdose, SSRI elimination times are further prolonged by the saturation of metabolic enzymes and by delayed absorption, especially for sustained-release preparations.

-          Electrolyte imbalance: hyponatremia, easily seen in the elderly [3].

-          Neural system: extra-pyramidal, hyperreflexia, Clonus, myoclonus [4].

-          Respiratory system: failure. Cough.

-          Gastrointestinal system: nausea, upset.

 

Presentation

 

-          Cause vomiting, mild CNS depression, or tremor.

-          Hyponatremia.

-          Unstable blood pressure. Arrhythmia. VT. Arrest, QRS QTc prolongation, Torsades de pointes [5].

-Bradycardia, hypotension: Fluvoxamine (Luvox)

- hyperreflexia, Clonus, myoclonus.

- Sweating, agitation.

- fever, coma, seizure (1.9%) [6].

 

Antidote and Treatment 

 

-          BLS, gastric lavage < 1 hr.  

-          Activated charcoal.

-          Not recommended for laxative.

-ACLS, inotropic agent.

-Nitroglycerin或Nitroprusside for hypertension。

-  magnesium sulfate 2 g IV over 2 min for Torsades de points

-  wide QRS: NaHCO3 1 to 2 mEq/kg IV push

- (benzodiazepine, BZD) for seizure.

- Serotonin antagonist:

     -Cyproheptadine (oral form; sedation) [7].

- (Extrapyramidal signs): Diphenylhydramine 50mg bid。

 

Disposition

 

-          Suspicious: observe 6-8 hours with ECG monitoring, if no symptoms, then may be discharged.

-          Citalopram, need observe longer to 12hours, observe arrhythmia / convulsion [8].

 

REFERENCES

 

[1]. https://pubmed.ncbi.nlm.nih.gov/35206480/

[2]. https://pubmed.ncbi.nlm.nih.gov/19361459/

[3]. https://pubmed.ncbi.nlm.nih.gov/34483534/

[4]. https://pubmed.ncbi.nlm.nih.gov/23391344/

[5]. https://pubmed.ncbi.nlm.nih.gov/31845095/

[6]. https://pubmed.ncbi.nlm.nih.gov/30521236/

[7]. https://pubmed.ncbi.nlm.nih.gov/20833944/

[8]. https://pubmed.ncbi.nlm.nih.gov/33489987/

 

Edited by Yu-Jang Su                 May 26, 2022