Trazodone Hydrochloride: Indications, Mechanism of Action, Dosage, Side Effects and Interactions

It is an atypical antidepressant for the treatment of depression and sleep disorders.

For example, insomnia but also disorders such as nightmares.

This drug is chemically similar to the other better known atypical antidepressants, such as Prozac and Zoloft, specific serotonin reuptake inhibitors. Still, it works on many different receptors as an agonist and not as a reuptake inhibitor.

Chemical formula

  • C19H22ClN5O.


Trazodone Hydrochloride is available in 50mg, 100mg, 150mg, and 300mg tablets.


Most commonly, Trazodone Hydrochloride is prescribed when a patient suffers from depression or complains of insomnia.

Although chemically an antidepressant, Trazodone Hydrochloride appears to be an effective sleep aid without the unwanted side effects associated with central nervous system depressants such as Valium, Librium, or Xanax.

Trazodone Hydrochloride is not a depressant at all, and the precise mechanism by which it promotes sleep and sedation is not well understood.


However, it has been approved for use in major depressive disorder and bipolar disorder when the patient’s presentation is depression and insomnia.

Trazodone Hydrochloride is prescribed for other conditions, such as anxiety and related disorders, such as bulimia and obsessive-compulsive disorder.

Pain syndromes like fibromyalgia can also be treated with Trazodone Hydrochloride. This drug was initially synthesized based on a theory of depression that proposed a link between depression and a lowered pain threshold.

Mechanism of action

Trazodone Hydrochloride is a serotonin antagonist and a reuptake inhibitor, which ensures that higher serotonin levels are available for circulation in the brain.

However, Trazodone Hydrochloride acts on many different receptors in the brain, not exclusively serotonin receptors, and its specific mechanism of action as an antidepressant and as a sleep aid is unknown.

It shares some similarities with central nervous system depressants, both mechanism and side effects.

But it is not reported to be as effective as the other central nervous system depressants, most commonly prescribed against depressive symptoms, except for insomnia.


This product is recommended only for those over 18 years of age: initially 150 mg per day in divided doses with food.

It can be increased by 50 mg per day at 3-4 day intervals.

The maximum dose is 400 mg per day in outpatients or 600 mg per day in hospitalized patients; most doses should be given at bedtime in divided doses.

Side effects

Trazodone Hydrochloride has fewer side effects than tricyclic antidepressants, but side effects similar to those experienced by CNS depressant users are frequently reported.

  • Headache or discomfort and heaviness.
  • Nausea and an unpleasant taste in the mouth.
  • Dry mouth.
  • Gastric distress: diarrhea or constipation.
  • Changes in appetite
  • Weight gain or loss.
  • Weakness, daytime fatigue
  • Anxiety.
  • Memory and concentration problems
  • Vision changes, blurred vision, and red eyes.
  • Perspiration
  • Drowsiness.
  • Sedation.
  • Dizziness
  • Syncope and arrhythmias.
  • Hypotension
  • Hyponatremia (especially in the elderly).

Sexual side effects are also reported less frequently than other central nervous system depressants.

Warnings and Contraindications

Trazodone Hydrochloride is metabolized in the liver and shares its specific mechanism with the metabolism of many other foods, beverages, and other substances.

This means that many potential drug interactions can occur.

One of those substances that can interact with Trazodone Hydrochloride and cause problems with metabolism.

Grapefruit juice is recommended not to be consumed while taking this medication.

Trazodone Hydrochloride is also a close enough chemical cousin to central nervous system depressants to carry the warning of suicide and require careful titration when use is discontinued.

Due to the effectiveness of Trazodone Hydrochloride as a sleep aid, care should be taken with daytime use of this medication.

Driving or operating machinery may not be advisable, especially during the first few weeks of getting used to the medicine.

For the same reason, any alcohol or central nervous system depressants while using Trazodone Hydrochloride should be carefully monitored.

Particular caution should be exercised if:

  • The patient has recently had a heart attack (risk of arrhythmias).
  • You drink an excessive amount of alcohol.
  • Take medicine to sleep.
  • You are under 18 years of age.
  • You have or have had epileptic fits or seizures.
  • You have severe liver, heart, or kidney disease.
  • The patient is pregnant, trying to get pregnant, or breastfeeding her baby.
  • You suffer from hyperthyroidism (excessive functioning of the thyroid gland).
  • You have difficulty urinating or urinating more often than usual.
  • You have narrow-angle glaucoma.
  • You have schizophrenia or another type of severe mental disorder.
  • You are over 65 years of age, and you will suffer more easily from side effects.
  • Have suicidal thoughts or worsening depression or anxiety disorder.


For the same reason, any alcohol or central nervous system depressants while using Trazodone Hydrochloride should be carefully monitored.

Interactions with monoamine oxidase inhibitors include isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine can cause a severe, possibly fatal interaction with Trazodone Hydrochloride.

Other medications can affect the removal of Trazodone Hydrochloride from the body, which can affect how Trazodone Hydrochloride works.

Examples include azole antifungals (such as itraconazole and ketoconazole), HIV protease inhibitors (such as ritonavir and indinavir), and macrolide antibiotics (such as erythromycin), rifamycin (such as rifampin), medications used to treat seizures (such as phenytoin). ), among others.

The risk of suffering from serotonin syndrome is greater when trazodone hydrochloride is taken together with medications that increase serotonin, such as: “ecstasy,” St. John’s wort, fluoxetine/paroxetine, duloxetine/venlafaxine, among others.