Tricyclic Antidepressants Pharmacology: Brush Up on Your TCAs – Part 1

Tricyclic Antidepressants Pharmacology: Brush Up on Your TCAs – Part 1

Tricyclic antidepressants (TCA) are one of the most significant lectures that you will encounter in your psychiatric nursing course. TCAs are just one of the leading antidepressants that will be discussed elaborately by Mike here at SimpleNursing.com.

After going through TCAs, we will also have separate videos for SSRs, MAOIs, and atypical antidepressants. Let’s get into it.

First Things First

Before going into the nitty-gritty details of TCAs, you first need to start with the pathophysiology. Things will not make sense if you have no idea about the pathophysiology. We’ve provided a 10-minute video on the introduction of pathophysiology so you can check that out to have a quick review before you go into your different medications.

Tricyclic Antidepressants – Description

Your first generation anti-depressant is your tricyclic antidepressants (TCA). You can easily remember TCAs as a Transportation Security Administration (TSA) – slow, drawn out, and the security process lags. Comparing it to TCAs, the therapeutic process is prolonged, taking a few weeks to a month. So, that’s the first thing to keep in mind:

            TCA = TSA = slow therapeutic range

What are the different types of TCAs?

  1. Amitriptyline (Elavil)
  2. Imipramine (Tofranil)
  3. Doxepin (Sinequan)

We’ve underlined Imipramine (Tofranil) just to emphasize that this drug is the most common TCA that you will encounter on your tests and in the clinical setting.

Test tip: Write this down on a notecard together with your pathophysiology of dopamine, serotonin, and norepinephrine. 

Tricyclic Antidepressants – Pathophysiology

There’s a block in the re-uptake of your norepinephrine and serotonin. Meaning, we are slowing down communication between neurons, thereby prolonging the neurotransmitters. Think of it as one side of a phone call is being delayed or put on hold from the other line to slow down the transmission of messages. Technically, we are blocking the re-uptake transmitters.

Norepinephrine (Levophed) is the catecholamine that helps in increasing the heart rate and blood pressure.

When TCAs are given, you are slowing down norepinephrine communication which is basically telling the body not to activate the heart severely and not squeeze those vessels that cause increased blood pressure.

Tricyclic Antidepressants – Side Effects

The main side effects of TCAs are:

  • Heart dysrhythmias
  • Hypotension
  • Anti-cholinergic effects like dryness
  • Confusion
  • Memory loss
  • Sedation

In cases of TCA toxicity, your patient will be experiencing toxicity level signs and symptoms known as EPSE or extra-pyramidal side effects. The EPSE of TCA are:

  • Tardive dyskinesia
  • Akinesia
  • Akathisia
  • Pseudoparkinsonism

Note: There is a separate video dedicated to the thorough discussion of EPSEs. So, we recommend you watch that video to get a better understanding of the aforementioned EPSEs because they are also NCLEX question favorites.

Tricyclic Antidepressants – Patient Education

It is imperative to lay out all the facts on patients taking TCAs and to their caregiver or support system as well. What are the things that you need to educate and emphasize?

  1. TCA = slow acting (six to eight weeks for maximum therapeutic levels)
  2. Suicide ideations = essentially important to monitor because it usually happens in the first month of patients taking anti-depressants

Suicide ideations are not just for your TCAs but all the other antidepressant medications as well.

Big NCLEX question for TCA:

Q: If your patients are feeling better and want to go home, what are you going to watch out for?

A: Suicide ideations.

If your answer is discharge planning, then that would be a big no-no.

Suicide ideations are the best answer because when major depressive patients feel better, technically they are still depressed, but with more energy.

During the major depression, patients do not feel like doing anything but sit like a lump on a log; they just don’t have the power to engage in any activity. However, after taking TCAs, depressed patients have enough energy to carry out thoughts of killing themselves.

Remember: Monitor for suicide ideations.

  1. Patients will have dry mouth and eyes, and their appetite is affected. Furthermore, patients will have low blood pressure.
  2. Patients will have orthostatic changes – sitting up then immediately passing out.
  3. No cardiac medications and no myocardial infarction or heart attack patients due to the involvement of norepinephrine.
  4. Wean off.

That’s it for your TCAs. On our next video, we will be discussing SSRIs.

See you there!

 

By | 2018-02-22T19:12:59-08:00 February 26th, 2018|Pharmacology, Psychiatry|Comments Off on Tricyclic Antidepressants Pharmacology: Brush Up on Your TCAs – Part 1

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