Understanding Trazodone 18: Demystifying a Medication Dosage Misconception

October 7, 2025 •

4 min read

As of 2022, trazodone was the 18th most prescribed drug in the United States, which may be the origin of the common query, "What is trazodone 18?". However, understanding the actual available strengths and uses of this serotonin modulator is crucial for patient safety and medication efficacy.

Quick Summary

This article explains why an 18mg dose of trazodone is a misconception and explores general information about trazodone, its uses, and potential side effects. It covers the medication's primary purpose as an antidepressant and its off-label use for insomnia, details administration, outlines potential side effects, and discusses the importance of supervised tapering.

Key Points

Dose Misconception: The query "trazodone 18" is likely a misunderstanding, as a standard 18mg dose does not exist. It may refer to its statistical ranking as the 18th most prescribed drug in the US in 2022.
Standard Dosages: Trazodone immediate-release tablets are typically available in various strengths, with off-label sleep dosages starting lower.
Dual Action: Trazodone acts as a serotonin antagonist and reuptake inhibitor (SARI), increasing serotonin availability while also having sedative effects due to histamine blockade.
Multiple Uses: The medication is primarily FDA-approved for depression but is commonly prescribed off-label at lower doses for insomnia.
Common Side Effects: Drowsiness, dry mouth, dizziness, nausea, and headache are among the more common side effects of trazodone.
Serious Risks: Potential serious side effects include serotonin syndrome, priapism, orthostatic hypotension, and increased risk of suicidal thoughts, especially in younger adults.
Tapering is Crucial: Abruptly stopping trazodone can cause withdrawal symptoms; a gradual dose reduction under medical supervision is recommended.

An initial search for 'what is trazodone 18' reveals a common point of confusion rooted in popular prescribing statistics and typical dose ranges. While trazodone is a widely used and effective medication, especially for depression and off-label for insomnia, it is not available in an 18mg tablet strength. Standard immediate-release tablets are manufactured in specific strengths. This article will clarify the facts behind this common query and provide a general overview of the medication.

What is Trazodone?

Trazodone is a prescription medication that belongs to a class of drugs known as serotonin receptor antagonists and reuptake inhibitors (SARIs). Its mechanism of action involves increasing the amount of serotonin in the brain by preventing its reabsorption, which helps regulate mood and emotional balance. Beyond its serotonergic effects, trazodone also blocks histamine receptors (leading to sedation) and alpha-1-adrenergic receptors (which can cause a drop in blood pressure). This multifaceted action profile is what makes trazodone potentially effective for different conditions.

Approved and Off-Label Uses

Originally approved by the FDA in 1981 for the treatment of major depressive disorder (MDD), trazodone is also frequently prescribed "off-label" for other conditions due to its unique properties.

Depression

For treating MDD, trazodone is used, and long-term adherence is important for antidepressant effects to become noticeable.

Insomnia

Trazodone's strong sedative effects have led to its widespread off-label use as a sleep aid. It is a popular option because it is not a controlled substance and has a lower risk of dependency compared to traditional sedatives.

Other Uses

Trazodone is also sometimes used off-label to treat anxiety disorders, schizophrenia, and alcohol withdrawal, though evidence for these uses is variable.

Trazodone Immediate-Release vs. Extended-Release

Patients may encounter different formulations of trazodone, including immediate-release (IR) tablets and, formerly, an extended-release (ER) version.


Feature	Immediate-Release (IR)	Extended-Release (ER)
Dosing	Often taken two or more times daily for depression. Typically taken once nightly for insomnia.	Typically taken once daily at bedtime for depression.
Dosage Forms	Available in various scored tablet strengths.	Previously available as bisectable tablets.
Absorption	Reaches peak plasma concentration relatively quickly.	Slower, more controlled release over an extended period.
Pros	Lower doses may be effective for sedating effects, lower risk of dependency.	Improved tolerability due to reduced peak serum concentration, once-daily dosing.
Cons	Higher doses may cause side effects due to relatively rapid peaks in serum concentration.	The extended-release formulation was formerly available and may not be as accessible.

Potential Side Effects and Precautions

Trazodone can cause a range of side effects, from mild to serious. It is crucial to be aware of these and to follow a healthcare provider's instructions carefully.

Common Side Effects

Drowsiness or fatigue
Dry mouth
Dizziness or lightheadedness, especially when standing
Nausea or constipation
Headache

Serious Side Effects

Serotonin Syndrome: A potentially life-threatening condition caused by an excess of serotonin, especially when combined with other serotonergic drugs.
Priapism: A painful, prolonged erection, which is a rare but serious side effect.
Orthostatic Hypotension: A significant drop in blood pressure when standing up, which can increase the risk of falls.
Increased Risk of Suicidal Thoughts: The FDA has issued a boxed warning for antidepressants, including trazodone, regarding an increased risk of suicidal thoughts and behaviors in young adults.

Precautions and Warnings

Do not stop abruptly: Abruptly discontinuing trazodone can lead to withdrawal symptoms, and the dose should be tapered down gradually under medical supervision.
Drug interactions: Inform your doctor of all other medications and supplements you are taking, as some, like MAO inhibitors and certain herbal supplements, can have dangerous interactions.
Alcohol: Avoid drinking alcohol while taking trazodone, as it can worsen side effects.
Existing conditions: Inform your doctor if you have a history of bipolar disorder, heart problems, or certain blood disorders.

Conclusion

In summary, the query "what is trazodone 18?" is likely a misunderstanding, possibly stemming from a statistic rather than an actual dose. A standard 18mg tablet of trazodone does not exist; the medication is typically available in various standard strengths for immediate-release formulations. It is primarily used to treat major depressive disorder but is also very commonly prescribed off-label at lower doses to help with insomnia. As with any prescription medication, understanding the correct administration, mechanism, and potential side effects is essential. Always consult a healthcare professional before starting, stopping, or adjusting a trazodone regimen to ensure safety and effectiveness.

This article is for informational purposes only and is not a substitute for professional medical advice. Always consult a qualified healthcare provider for any health concerns or before making any decisions related to your treatment.

For further information on trazodone, you can refer to authoritative sources such as MedlinePlus.

Frequently Asked Questions

The query 'trazodone 18' is likely a mistake or refers to a statistic, such as the medication ranking as the 18th most prescribed drug in the U.S. in 2022. There is no standard 18mg tablet dose of trazodone.

Trazodone immediate-release tablets are commonly available in various strengths. An extended-release formulation was also previously available.

Trazodone is FDA-approved for treating major depressive disorder and is also very commonly used off-label as a sleep aid for insomnia. Different doses are typically used for each purpose.

Trazodone increases serotonin levels in the brain by blocking its reabsorption (serotonin reuptake inhibition). It also blocks certain serotonin receptors, histamine receptors (causing sedation), and alpha-1-adrenergic receptors.

Common side effects include drowsiness, dry mouth, dizziness, nausea, headache, and blurred vision.

Abruptly stopping trazodone can cause withdrawal symptoms, such as dizziness, nausea, anxiety, and agitation. The dosage should always be gradually reduced under a doctor's supervision.

Trazodone is not a controlled substance and is considered to have a low potential for abuse or dependency compared to traditional sleep medications like benzodiazepines. However, long-term use can lead to physical dependence and uncomfortable withdrawal symptoms if stopped suddenly.

Yes, trazodone can have significant drug interactions, particularly with monoamine oxidase inhibitors (MAOIs), other antidepressants, and certain herbal supplements. Patients must inform their doctor about all medications and supplements they are taking.