Trazodone hydrochloride is a prescription antidepressant that works by increasing serotonin activity in the brain. It belongs to a class of drugs called serotonin antagonist and reuptake inhibitors, or SARIs. While its FDA-approved use is treating major depressive disorder in adults, it’s widely prescribed at lower doses for insomnia and several other conditions.
How Trazodone Works in the Brain
Trazodone does two things simultaneously. It blocks the brain from reabsorbing serotonin (a chemical messenger tied to mood), which leaves more serotonin available between nerve cells. At the same time, it blocks certain serotonin receptors that can contribute to anxiety and sleep disruption. This dual action is what sets it apart from more commonly known antidepressants like SSRIs, which only prevent serotonin reabsorption.
Trazodone also blocks a type of receptor involved in blood pressure regulation, which is why dizziness when standing up is one of its most common side effects.
What Trazodone Is Prescribed For
The only FDA-approved use is major depressive disorder in adults. In practice, though, trazodone is one of the most frequently prescribed sleep aids in the United States. Doses of 50 to 100 mg at bedtime have been shown to help with insomnia related to depression, with 100 mg appearing to be the most effective dose for sleep.
Trazodone is also used off-label for anxiety, Alzheimer disease-related agitation, substance misuse, bulimia, fibromyalgia, and obstructive sleep apnea. For post-traumatic stress disorder, doses of 50 to 200 mg have been shown to reduce nightmares and improve sleep habits, particularly when first-line treatments haven’t worked. The American Academy of Sleep Medicine specifically suggests trazodone for PTSD-associated nightmares.
How Quickly It Takes Effect
The sedating effects kick in fast. Most people notice drowsiness within the first few days of starting trazodone, which is why it’s often taken at bedtime. The mood-lifting effects take considerably longer. You can expect some improvement in depression symptoms within one to two weeks, but the full antidepressant benefit typically takes four to six weeks to develop. This gap between the sleep effects and the mood effects is important to understand so you don’t assume the medication isn’t working for depression just because your mood hasn’t shifted in the first week.
Common Side Effects
The most frequently reported side effects include:
- Drowsiness and fatigue, which can persist into the morning, especially at higher doses
- Dizziness or lightheadedness, particularly when standing up quickly from a sitting or lying position
- Blurred vision
- Sweating
- Confusion
Less common side effects include headaches, tingling or “pins and needles” sensations, poor coordination, muscle tremors, nervousness, and changes in heart rate. Skin rash and unusual excitement are rare.
Serious Risks to Be Aware Of
Like all antidepressants, trazodone carries an FDA black box warning about increased risk of suicidal thoughts and behavior in children, adolescents, and young adults during the early weeks of treatment or when the dose changes.
Trazodone can cause a dangerous condition called serotonin syndrome, especially when combined with other medications that raise serotonin levels. Warning signs include a fast heartbeat, fever, muscle spasms or twitching, restlessness, nausea, vomiting, and hallucinations. This is a medical emergency.
Heart rhythm changes, specifically a problem called QT prolongation, are another serious concern. Symptoms like a pounding or uneven heartbeat, fainting, or sudden dizziness warrant immediate medical attention.
One rare but notable risk for men is priapism, a prolonged and painful erection that requires emergency treatment. Though uncommon, it’s a well-documented side effect specific to trazodone that doesn’t typically occur with other antidepressants.
Drug Interactions
Trazodone should not be combined with a class of older antidepressants called MAOIs, as the combination can trigger life-threatening serotonin syndrome. Other medications that raise serotonin levels, including many antidepressants, certain migraine drugs, and the supplement St. John’s wort, also increase this risk.
Because trazodone causes drowsiness, combining it with alcohol, sedatives, or other central nervous system depressants intensifies the sedation and can be dangerous. Certain medications that affect liver enzymes can also change how quickly your body processes trazodone, potentially raising or lowering its levels in your blood.
Stopping Trazodone Safely
Stopping trazodone abruptly can cause withdrawal symptoms including anxiety, irritability, dizziness, nausea, headaches, fatigue, insomnia, sweating, and mood swings. Some people experience more severe effects like vivid dreams, confusion, or, in rare cases, seizures.
Tapering is the standard approach. This typically means reducing the dose by 10% to 25% every one to two weeks, depending on how you respond. If withdrawal symptoms become difficult to manage at any point, the taper can be paused at the current dose to allow your body more time to adjust before the next reduction. The length of time you’ve been taking trazodone and your current dose both influence how gradual the taper needs to be.