Pharmacology · chapter 13 · Psychopharmacologic Drugs
Antidepressants
The 14 things this section of the textbook says that you are most likely to be asked about — quoted word for word, not retold. Then 6 practice questions with the reasoning.
Key points
Anticholinergic effects of TCAs
Tricyclic antidepressants block acetylcholine (muscarinic) receptors; therefore, blurred vision, dry mouth, constipation, and urine retention are common due to the anticholinergic properties.
TCAs and glaucoma
Glaucoma is a contraindication because the anticholinergic properties can increase intraocular pressure (IOP).
TCAs and the QTc interval
Because TCAs can prolong the heart’s QTc interval, use with caution in clients who have bradycardia, who are taking drugs that can induce bradycardia, or who have electrolyte abnormalities that could result in a life-threatening dysrhythmia.
Separating fluoxetine and MAOIs
MAOIs and fluoxetine should be separated at least 5 weeks apart to prevent serotonin syndrome. The remaining SSRIs and MAOIs should be separated by 2 weeks.
Signs of serotonin syndrome
Serotonin syndrome is characterized by altered mental status, anxiety, hallucinations, hyperpyrexia, muscle rigidity, hyperreflexia, diaphoresis, and tremor.
SSRIs and bleeding risk
These drugs can increase the risk for bleeding, so caution needs to be exercised for clients taking aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and anticoagulants because these can further the risk of bleeding.
SNRIs and blood pressure
SNRIs have the potential to increase blood pressure; therefore, anyone with uncontrolled hypertension should avoid this class of drugs.
Screen for bipolar disorder first
Clients should be screened for bipolar disorder before starting therapy to prevent mania or hypomania.
Bupropion seizures with eating disorders
A higher incidence of seizures was observed in clients being treated with the immediate-release formulation who have a current or past diagnosis of anorexia or bulimia nervosa.
Why MAOIs are rarely used
MAOIs are not often used in practice today, mainly because of the numerous food and drug interactions that produce severe hypertension. Blood pressure could be elevated enough to cause a stroke or myocardial infarction.
How tyramine raises blood pressure
Because these drugs block the monoamine oxidase enzyme, tyramine is absorbed systemically. It is transported to the adrenergic nerve terminals, where it causes a sudden release of significant amounts of NE.
Flu-like symptoms may mean low WBC
If a client experiences generalized malaise, chills, fever, or myalgia, similar to the flu, this may indicate a low white blood cell (WBC) count. The provider should be notified.
How long until antidepressants work
Be aware that these drugs can take 2 weeks to start seeing effects and 4–6 weeks for full therapeutic effects.
Suicide risk in young people
In short-term trials, antidepressant use for major depressive disorder increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults under age 24 when compared to placebos.
Terms to know
- Depression
- Depression is an affective disorder in which the person experiences feelings of sadness, anger, frustration, hopelessness, and helplessness.
- off-label
- Several of these medications are also prescribed “off-label” for other psychiatric disorders, meaning the prescriber is using them for purposes other than what they were approved for by the Food and Drug Administration (FDA) but still based upon scientific rationale (Van Norman, 2023).
- hyperpyrexia
- The use of opioids and MAOIs can result in hyperpyrexia (high fever).
Practice questions
Stuck on select-all-that-apply? How to take them one option at a time.
The graded version needs JavaScript. Every question is below anyway, with the answer and why.
Every question here, with the answer
A client taking phenelzine asks which foods to avoid. Which food should the nurse name?
- Green beans
- White rice
- Aged cheeses
- Apples
Answer: Aged cheeses
Clients on an MAOI must avoid foods high in tyramine, and aged cheeses are on that list. With the enzyme blocked, tyramine is absorbed and triggers a sudden release of norepinephrine that can cause severe hypertension. The other foods are not on the section's tyramine list.
A client taking an SSRI was recently given tramadol. Which findings suggest serotonin syndrome? Select all that apply.
- Muscle rigidity
- Diaphoresis
- Flaccid muscles
- High fever
- Hypothermia
Answer: Muscle rigidity, Diaphoresis, High fever
Tramadol with an SSRI increases the risk of serotonin syndrome, which is characterized by altered mental status, anxiety, hallucinations, hyperpyrexia, muscle rigidity, hyperreflexia, diaphoresis and tremor. Hypothermia and flaccid muscles are the opposite of these findings.
A client is being switched from fluoxetine to an MAOI. What is the minimum interval the nurse expects between the two drugs?
- 2 weeks
- 1 week
- 5 weeks
- 24 hours
Answer: 5 weeks
Because fluoxetine has a long half-life, it must be separated from MAOIs by at least 5 weeks to prevent serotonin syndrome. The 2-week interval applies to the other SSRIs, and shorter intervals are unsafe.
A client with a past diagnosis of bulimia nervosa is prescribed immediate-release bupropion to quit smoking. Why should the nurse question this order?
- Bupropion is not used for smoking cessation.
- Bupropion causes severe orthostatic hypotension.
- The client has a higher risk of seizures.
- Bupropion commonly causes sexual dysfunction.
Answer: The client has a higher risk of seizures.
A higher incidence of seizures was seen with immediate-release bupropion in clients with a current or past diagnosis of anorexia or bulimia nervosa. Unlike other antidepressants, bupropion does not cause sexual dysfunction or orthostatic hypotension, and smoking cessation is one of its indications.
A nurse is teaching a client who is starting an SSRI. Which instructions should the nurse include? Select all that apply.
- Report blood in the urine, tarry stools or bleeding gums.
- Expect the full effect within the first day.
- Avoid aspirin and NSAIDs.
- Stop the drug on your own if sexual problems occur.
- Tell the provider right away about worsening depression or thoughts of suicide.
Answer: Report blood in the urine, tarry stools or bleeding gums., Avoid aspirin and NSAIDs., Tell the provider right away about worsening depression or thoughts of suicide.
SSRIs raise bleeding risk, so clients avoid aspirin and NSAIDs and report signs of bleeding, and any increase in depression or suicidal thoughts is reported immediately. Full effects take weeks, and sexual dysfunction should be reported so it can be addressed, not handled by stopping the drug.
A client taking mirtazapine reports chills, fever and muscle aches, like the flu. What should the nurse do?
- Tell the client to take an extra dose at bedtime.
- Advise the client to stop eating tyramine-rich foods.
- Reassure the client that this is expected sedation.
- Notify the provider because this may indicate a low white blood cell count.
Answer: Notify the provider because this may indicate a low white blood cell count.
Agranulocytosis is an identified adverse effect, and flu-like malaise, chills, fever or myalgia may signal a low WBC count, so the provider should be notified. These symptoms are not sedation, extra doses are not indicated, and the tyramine restriction applies to MAOIs.
Where every quote comes from
Section 13.1 Antidepressants of Pharmacology for Nurses by Tina Barbour-Taylor, Leah Mueller (Sabato), Donna Paris, Dorie Weaver, OpenStax, 2024. Read the whole section free at openstax.org.
The textbook is licensed under CC BY-NC-SA 4.0. This page quotes it word for word and adds the headings, the order and the practice questions; references to the book's figures and stray spaces left by its formatting are removed. The page is shared under the same licence. Nothing here is sold.