Antidepressants: The Need-to-Know Series (Part 3: The SSRIs, SNRIs, NDRI)

Your neighbor can’t stop talking about the wonders of Lexapro. She suggests you talk to your doctor about an SSRI for your depression and anxiety. You reply, “What’s an SSRI?”

In Part 1 of our our series we reviewed some history, the tricyclic antidepressants (TCAs), and the tetracyclic antidepressants (TeCAs). And we covered the monoamine oxidase inhibitors (MAOIs) in Part 2. Just click on the links – Part 1 Part 2

Today we’re going to explore the selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and a norepinephrine-dopamine reuptake inhibitor (NDRI).

Selective Serotonin Reuptake Inhibitors (SSRIs)

The first SSRI was fluoxetine (Prozac), introduced in 1988. The SSRIs are – citalopram (Celexa), dapoxetine (Priligy), escitalopram (Lexapro), fluoxetine (Prozac), fluvoxamine (Luvox), paroxetine (Paxil), sertraline (Zoloft), and vilazodone (Viibyrd) (approved by the FDA just last month).

How Do SSRIs Work?

Serotonin is a neurotransmitter believed to be involved in the generation of mood and anxiety issues. In Part 1 we discussed the dynamics of reuptake. The SSRIs inhibit the reuptake of serotonin, allowing more to stick around as neurons communicate.

Why Would I Take an SSRI?

The SSRIs are prescribed for the treatment of depression, anxiety disorders, eating disorders, chronic pain, irritable bowel syndrome, premature ejaculation, and more.

Any Side Effects?

SSRI side effects include dry mouth, constipation, nausea, fatigue, urinary retention, appetite/weight changes, tremor, difficulty achieving orgasm, erectile dysfunction, and decreased libido.

Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)

The first SNRI, venlafaxine (Effexor), was introduced in 1994. The SNRIs are – venlafaxine (Effexor), desvenlafaxine (Pristiq), duloxetine (Cymbalta), milnacipran (Dalcipran), and sibutramine (Meridia).

How Do SNRIs Work?

Refer to the “How Do’s” of the SSRIs, and add the neurotransmitter norepinephrine.

Why Would I Take an SNRI?

First and foremost, SNRIs are prescribed for depression. They’re also used for the treatment of the anxiety disorders, neuropathic pain, fibromyalgia syndrome, and the relief of menopausal symptoms.

Any Side Effects?

Refer to the side effects for the SSRIs. However, some reports suggest SNRI side effects may not be as severe. And with regard to sexual side effects, though the SNRIs have the same symptoms as the SSRIs, an increase in libido has been reported.

Any Other Concerns?

High blood pressure needs to be managed and monitored. Duloxetine (Cymbalta) has been associated with liver failure, so it’s not an option for chronic alcohol users or those with liver disease.

Norepinephrine-Dopamine Reuptake Inhibitor (NDRI)

Bupropion (Wellbutrin, Zyban, Budeprion) made the scene in 1974. On its own it’s an effective antidepressant. But it’s frequently used as an add-on when the SSRIs aren’t working as expected. It’s also used as a smoking cessation aid. Of note, bupropion does not cause weight gain or sexual dysfunction.

How Does bupropion (Wellbutrin, Zyban) Work?

Bupropion is known as an atypical antidepressant. What makes it unique is its dance with the neurotransmitter dopamine. It’s twice that of its action with norepinephrine. It’s success as a smoking cessation aid is due to its effect on acetylcholine (a neurotransmitter) receptors.

Why Would I Take It?

Bupropion is used to treat depression, the symptoms of smoking cessation, social phobia (aka social anxiety), anxiety co-existing with depression, sexual dysfunction, obesity, adult ADHD, and neuropathic pain. It may also be useful in the treatment of Crohn’s Disease and psoriasis.

The fact that bupropion doesn’t cause weight gain or sexual dysfunction makes it the preferred choice for many.

Any Side Effects?

Common side effects include agitation, anxiety, buzzing in the ears, skin rash, hives, itching, and headache.

Bupropion lowers seizure threshold, but at recommended doses it shouldn’t present problems. Hypertension, resulting in headaches, blurred vision, and other symptoms could be an issue. Blood pressure monitoring may be suggested.

 Any Other Concerns?

Bupropion may cause anaphylaxis, which can be life-threatening. So if you’re experiencing itching, a rash, swelling of the face, tongue, and throat; breathing difficulty, or chest pain – seek immediate medical attention.

The following apply to all of the medicines discussed in the series…

In 2007, the FDA ordered expanded black-box warnings regarding an increased risk of suicidal symptoms in users younger than 24. There’s quite a bit of controversy here; nonetheless, I need to provide the heads-up.

Alcohol, drug, and supplement interaction is always a concern. Chat with your physician regarding the meds or supplements you’re taking – or considering.

The sudden cessation of any antidepressant is a bad idea. You won’t like the outcome! Here’s a link to the first piece of a series I did on antidepressant discontinuation syndrome.

Well, that’ll do it for today’s discussion. Be sure to come back tomorrow for the final piece in the series – a summary, which will include my personal thoughts on antidepressants.

You may find the FDAs Information for Consumers website helpful. Click here and you’re there.

Be sure to join the chipur crowd on my free weekly newsletter mailing list. And I’ll send along a gift! Click right here.