Trazodone hydrochloride is the active pharmaceutical ingredient (API) used in certain antidepressant medications. It is a triazolopyridine derivative in the serotonin‐antagonist-and-reuptake-inhibitor (SARI) class. In pure form it appears as a white to off-white crystalline powder. Its molecular formula is C₁₉H₂₂ClN₅O·HCl (CAS 25332-39-2; MW ≈408.3 g/mol). Common brand names for trazodone formulations include Desyrel (immediate-release tablets) and Oleptro (extended-release tablets).
Mechanism of Action: Trazodone works by inhibiting serotonin (5-HT) reuptake and antagonizing certain serotonin receptors (notably 5-HT₂A). It also blocks histamine H₁ and α₁-adrenergic receptors. These combined actions produce antidepressant effects but also cause sedation (via H₁ blockade) and can lead to orthostatic hypotension (α₁ blockade).
Indications and Use: Trazodone HCl is FDA-approved for the treatment of major depressive disorder (MDD) in adults. In practice, psychiatrists often prescribe it off-label for insomnia or sleep disturbances because of its sedating properties. It may also be used off-label for anxiety, PTSD, and other conditions (e.g. fibromyalgia or bulimia).
Administration: As an API powder (USP grade), trazodone HCl is used to manufacture tablets or capsules. Clinically, trazodone is typically given orally (often 50–150 mg at bedtime for depression or insomnia). The tablet label advises taking trazodone shortly after a meal or light snack to improve absorption and tolerability.
Adverse Effects and Safety: Common side effects include drowsiness/sedation, dizziness, headache, nausea, and dry mouth (anticholinergic effect). Patients may experience orthostatic hypotension (from α₁ blockade). Although trazodone can improve sleep, caution is needed in activities requiring alertness until tolerance develops. Rare but serious risks include QT-interval prolongation and Torsade de Pointes (due to hERG channel effects) and priapism (sustained erection). As with all antidepressants, there is a warning for suicidal thinking in young adults. Importantly, trazodone is not a controlled substance – it has little abuse potential.
Quality and Regulatory: In pharmaceutical terminology, an “API” is defined as “any substance… intended to be used in the manufacture of a pharmaceutical dosage form and that, when used, becomes the active ingredient”. The suffix “USP” indicates compliance with United States Pharmacopeia standards for identity, strength, quality, and purity. (In fact, U.S. law requires that prescription drugs meet USP monograph standards.) Thus Trazodone Hydrochloride, USP is the pure drug substance meeting official compendial tests. USP-grade trazodone HCl is supplied in bulk (e.g. gram-to-kilogram quantities) for use by manufacturers and compounding pharmacies. According to suppliers, it is a crystalline powder that is non-hygroscopic; it is typically stored at controlled room temperature (15–25 °C) in a tightly closed container.
Summary of Key Points:
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Chemical Identity: Trazodone HCl (CAS 25332-39-2) – a SARI-class antidepressant.
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Appearance: White/off-white crystalline powder (USP grade).
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Mechanism: Inhibits serotonin reuptake and blocks 5-HT₂A receptors; also blocks H₁ and α₁.
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Uses: FDA-approved for major depression in adults; often used off-label for insomnia and anxiety.
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Quality: “USP” means it meets official pharmacopeial standards for purity/identity; pharmacists regard it as the active drug substance in trazodone formulations.
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Safety: Commonly causes sedation and hypotension; watch for dry mouth, syncope, QT prolongation, and (rarely) priapism. It is not habit-forming and is not scheduled.
These details provide an overview of trazodone hydrochloride as a USP-grade API powder, covering its identity, pharmacology, uses, and quality standards
CAS Number: 1197-18-8
