Article No. 86

How would you rate this article?

Awful

Poor

Average

Good

Perfect

Create a Notebook

You currently don't have any notebooks.

If you want to save this article into a notebook, you can create one now.

Flag/Report
Article No. 86

Instructions:

What is the issue?

Let us know in a brief paragraph or sentence why you are flagging this article. Here are some other issues we, at Medzcool, would like to know about:

  • Spam or misleading content
  • Violation of privacy
  • Unnescessary sexual content
  • Unnescessary violent content
  • Hateful or abusive content
  • Promotion of harmful acts

Report:

Flagged articles and users are reviewed withing 24 - 48 hours upon submission of a report. The report will be reviewed to determine whether the article and it's author (user) has violated Medzcool's Terms of Use and/or Community Guidelines. Accounts are penalized for violations to either the Terms of Use and/or Community Guidlines. Repeated violations can lead to account termination.

Thank you for your report, it will be reviewed within the next 24-48 hrs.
Antidepressants
ARCHIVE
RATE
REPORT/FLAG

Antidepressants

(2)

Introduction

Antidepressants are a class of drugs that are commonly used to treat various psychiatric disorders or presentations such as major depressive disorder, anxiety disorders, eating disorders and even chronic pain, neuropathic pain among many more. 

The mechanism of action of these medications are many and complex:

Mechanism of Action of different antidepressants

Mechanism of Action of different antidepressants

We will review some of the common antidepressants in this article including: Selective Serotonin Reuptake Inhibitors (SSRI), Selective Norepinephrin Reuptake Inhibitors (SNRI), Tricyclic Antidepressants (TCA), Monoamine Oxidase Inhibitors (MAOI).

Selective Serotonin Reuptake Inhibitors

Common Medications:

  • fluoxetine, paroxetine, sertraline, citalopram

Remember these by:

Flashbacks paralyze senior citizens. (fluoxetine, paroxetine, sertraline, citalopram)

Mechanism of Action:

  •  5-HT–specific reuptake inhibitors

Clinical Uses

  • Depression 

  • Generalized anxiety disorder and panic disorders 

  • Obssessive Compulsive Disorder.

Side Effects

  •  GI distress

  • Sexual dysfunction (anorgasmia and decreased libido) 

  • Serotonin syndrome  with any drug that increases 5-HT (e.g., MAO inhibitors, SNRIs, TCAs)

    • Patient presents with hyperthermia, confusion, myoclonus, cardiovascular collapse, flushing, diarrhea, seizures.

    • Treatment: cyproheptadine (5-HT receptor antagonist).

Selective Norepinephrine Reuptake Inhibitors

Common Mediations:

  • Venlafaxine, duloxetine

Mechanism of Action: 

  • Inhibit 5-HT and norepinephrine reuptake

Clinical Use:

  • Major Depression.
  • Venlafaxine is also commonly used for generalized anxiety and panic disorders 
  • Duloxetine is also commonly used for diabetic neuropathy.

Side Effects

  • can increase blood pressure
  • GI upset: nausea

Tricyclic antidepressants

Common Mediations:

  •  Amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, doxepin, amoxapine

Remember:

Most TCAs end with the suffix -iptyline or -ipramine

Mechanism of Action: 

  •  Inhibit the reuptake of norepinephrine and 5-HT.

Clinical Use:

  • Major Depression
  • Fibromyalgia.
  • Clomipramine can also be used of Obsessive Compulsive Disorder

Side Effects

  •  Sedation, α1 -blocking effects including postural hypotension, and atropine-like (anticholinergic) side effects (tachycardia, urinary retention, dry mouth). 3°  TCAs (amitriptyline) have more anticholinergic effects than 2°  TCAs (nortriptyline) have. Desipramine is less sedating, but has a higher seizure incidence.

  • Anticholinergic side effects

Remember tCa:

Convulsions, Coma, Cardiotoxicity (arrhythmias), Confusion;

TCA Overdose

In a TCA overdose, patients will initially be drowsy and susequently go into cardiac arrest. The arrest is secondary to a ventricular arrhythmia. Prior to arrrest their EKG may look like this:

EKG with feature of a TCA overdose secondary to sodium channel blockade

EKG with feature of a TCA overdose secondary to sodium channel blockade

Patient's will go into cardiac arrest because of a ventricular arrhythmia. You can recognize the abnormality on and EKG prior to the arrest:

  • Interventricular conduction delay:
    • QRS > 100 ms 
  • Findings suggestive of right axis deviation:
    • Terminal R wave > 3 mm in aVR
    • R/S ratio > 0.7 in aVR

Treatment is with sodium bicarbonate.

 

Monoamine Oxidase Inhibitors

Common Medications:

  • Tranylcypromine, Phenelzine, Selegiline

Mechanism of Action:

  • Nonselective MAO inhibition which will cause an increase levels of amine neurotransmitters (norepinephrine, 5-HT, dopamine), 

Clinical Uses

  • Depression 

  •  Anxiety

Side Effects

  •  Hypertensive crisis (most notably with ingestion of tyramine, which is found in many foods such as wine and cheese);

  • Serotonin Syndrome

    • Do not use MAOIs with SSRIs, TCAs, St. John’s wort, meperidine, and dextromethorphan

Are you enjoying this article? Sign-up to see more and join the community of medical professionals
Add Section
  • New Section
    Creates a new section with
    subtitle and text

  • Text Block
    Insert text without a subtitle

  • Image
    Insert an inline image

Add Margin
  • Text Block
    Insert text without a subtitle

  • Image
    Insert an inline image

Article Type (optional)

File limit size: 2MB. Accepted files: .png, .jpg, .jpeg

Including tags helps other users find your article easier.

DISCARD CHANGES & EXIT

File limit size: 8MB. Accepted files: .png, .jpg, .jpeg

Choose Layout
Default Layout
Layout 1 - Caption below
Layout 2 - Side caption
DISCARD CHANGES & EXIT
Add Margin

File limit size: 2MB. Accepted files: .png, .jpg, .jpeg

DISCARD CHANGES & EXIT