The NCLEX exam might not test you directly on the mode of action or basically how these drugs work, but rather it will focus on safety issues regarding the medication and how it affects the client.

For instance, you always clarify any new prescription, monitor clients, and note any new thoughts of suicide or unusual behavior, worsening depression, or sudden mood changes.

All psychiatric drugs usually decrease blood pressure. So as a nurse, you’ll need to teach slow position changes for the risk of falling. These medications can also cause weight changes (mostly weight gain), and it’s important to inform the client of any expected side effects.

It’s crucial to note that antidepressants can increase suicidal thoughts in clients’ first few weeks of treatment. This is a bigger risk for young adults (18 to 24 years old).

It’s also important to note to never mix SSRIs with St. John’s wort or MAOIs with other antidepressants. This could lead to deadly serotonin syndrome, a condition in which the body produces too much of the neurotransmitter serotonin. So a two-week washout period (stopping one medication before another is started) is needed.

SSRI Drugs

Selective serotonin reuptake inhibitors (SSRIs) are given mainly for depression, anxiety, and post-traumatic stress disorder (PTSD). This type of antidepressant is often tested on nursing quizzes and exams.

SSRIs are called “selective” because they have a specific chemical structure that prevents them from crossing the blood-brain barrier and affecting other organs. This allows SSRIs to be used as antidepressants without causing some of the side effects of other antidepressants, such as sedation or weight gain.

SSRIs inhibit serotonin reuptake, so serotonin levels are increased in the body.

Most common SSRI drug names include:

• Sertraline
• Citalopram
• Escitalopram
• Paroxetine
• Fluoxetine

Side effects of SSRIs

• Sexual dysfunction
• Weight Gain
• Insomnia (NOT sleepiness or sedation)

Side effects from SSRIs usually improve after three months.

SSRI Mechanism of Action

The mechanism (or mode) of action for SSRIs is typically not tested on the NCLEX, but it will most likely be tested on nursing pharmacology exams:

• Inhibits the reuptake of Serotonin
• So Serotonin levels are increased

SSRI Nursing Mnemonic

To help memorize what SSRIs do and their drug names, remember Effective For Sadness, Panics, & Compulsions.

Effective – Escitalopram
For – Fluoxetine
Sadness – Sertraline
Panic – Paroxetine
Compulsions – Citalopram

MAOI Drugs

Monoamine oxidase inhibitors (MAOIs) are powerful antidepressants used for depression, panic disorder, and social phobia. These are the first and oldest antidepressants.

Clients using MAOIs have to avoid foods rich in tyramine, including aged cheeses, aged/pickled/smoked meats, beer, wine, yeast extracts, ginseng, sauerkraut, and avocado.

Eating foods high in tyramine with MAOIs can cause a massive headache. Tyramine is an amino acid that helps regulate blood pressure, and can actually trigger hypertension crises. This can lead to a heart attack or a CVA stroke.

Teach clients to start an MAOI-friendly diet at least two weeks before starting the medication, and continue for two weeks after stopping.

MAOIs do not mix with other antidepressants. NEVER start a client on a new antidepressant while tapering off an MAOI.

Most common MAOI drug names include:

• Phenelzine
• Selegiline
• Isocarboxazid
• Tranylcypromine

Side Effects of MAOIs

The most common side effect of using MAOIs is a rise in blood pressure. This can cause headaches, dizziness, nausea, and vomiting. It can also cause vision or hearing loss problems if left untreated for too long.

Other common side effects include:

• Dry mouth
• Constipation
• Diarrhea
• Blurred vision
• Signs of serotonin syndrome (fever, confusion, seizures)

Using MAOIs can possibly result in experiencing a hypertensive crisis, which can be fatal. Look out for these signs and symptoms:

• Hypertension (high blood pressure)
• Blistering of the skin or mucous membranes (nosebleeds and sore throat)
• Seizures or convulsions
• Unresponsiveness or coma

MAOI Mechanism of Action

MAOIs are responsible for blocking the monoamine oxidase enzyme, which breaks down neurotransmitters from the brain. MAOIs inhibit the breakdown of norepinephrine, serotonin, dopamine and tyramine, which increases their levels in the cells in the brain affected by depression.

MAOI Nursing Mnemonic

To remember MAOI drug names, remember TIPS:

Tranylcypromine
Isocarboxazid
Phenelzine
Selegiline

TCA Drugs

Tricyclic antidepressants (TCAs) are used for treating depression and anxiety – and they also help clients who suffer from neuropathy or neuropathic pain associated with diabetes and fibromyalgia.

Their anti-depressive effects are attributed to the synapse’s elevated norepinephrine and serotonin levels. Serotonin and norepinephrine are more concentrated in the synaptic cleft as a result of their ability to prevent their absorption in presynaptic terminals.

TCA drug names typically have suffixes -ipramine or -iptyline, with the exception of Doxepin and Amoxapine. These include:

• Amitriptyline
• Amoxapine
• Desipramine (Norpramin)
• Doxepin
• Imipramine
• Nortriptyline
• Protriptyline
• Trimipramine

Side Effects of TCAs

The common side effects of using TCAs include:

• Dry mouth
• Constipation
• Blurred vision
• Photophobia
• Urinary retention
• Sweating seizures
• Drowsiness or dizziness

TCA Mechanism of Action

Tricyclic antidepressants (TCA) act on approximately five different neurotransmitter pathways to achieve their effects. TCAs increase serotonin and norepinephrine while blocking the action of acetylcholine.

SNRI Drugs

Serotonin and norepinephrine reuptake inhibitors (SNRIs) help relieve symptoms of depression, anxiety, and pain associated with fibromyalgia. SNRIs are dual-purpose drugs – for both depression and pain.

SNRIs often have a mild effect on dopamine as well, which can help stabilize moods and increase motivation.

Most common SNRI drug names include:

• Venlafaxine
• Desvenlafaxine
• Duloxetine

Side Effects of SNRIs

The most common side effects associated with SNRIs include:

• Nausea
• Vomiting
• Dizziness
• Headaches
• Weight gain
• Dry mouth
• Constipation
• Sweating
• Sexual dysfunction

These are usually mild to moderate in severity, and typically resolve after a few days of treatment.

SNRI Mechanism of Action

The mechanisms of action for SNRIs are similar to those of SSRI antidepressants.

SNRIs work by inhibiting the reuptake of serotonin and norepinephrine into the presynaptic nerve terminal (so that more of them remain in the synapse longer). This increases their ability to bind with receptors in specific regions of the brain associated with regulating mood and behavior.

SNRI Nursing Mnemonic

To memorize SNRI drugs, remember Vexed & Depressed:

Vexed – Venlafaxine
Depressed – Duloxetine & Desvenlafaxine (active metabolite of Venlafaxine)

Conclusion of Types of Antidepressants

Antidepressants are a class of medications used to treat the symptoms of major depression, anxiety disorders, and other mood disorders.

The most common types of antidepressants are selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), and monoamine oxidase inhibitors (MAOIs). Newer drugs include serotonin-norepinephrine reuptake inhibitors (SNRIs).

Antidepressants have been shown to be effective in treating these conditions, but they can have side effects that may make them unsuitable for some clients.

Sources

https://www.ncbi.nlm.nih.gov/books/NBK557791/
​​https://www.timeofcare.com/ssri-snri-mnemonics/