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Zonalon (DOXEPIN)
Zonalon works by blocking histamine H1 receptors in the brain, which helps to reduce anxiety and itching, and improve mood.
Zonalon (Doxepin) is a tricyclic antidepressant small molecule that targets the histamine H1 receptor. Originally developed by Pfizer's predecessor, it was FDA-approved in 1969 for various indications including anxiety, atopic dermatitis, and severe major depression with psychotic features. As an off-patent medication, Zonalon is available from 35 generic manufacturers. Key safety considerations include its potential for cardiac and anticholinergic side effects. Its commercial status allows for generic competition, making it a widely accessible treatment option.
At a glance
| Generic name | DOXEPIN |
|---|---|
| Sponsor | Pfizer |
| Drug class | Tricyclic Antidepressant |
| Target | Histamine H1 receptor |
| Modality | Small molecule |
| Therapeutic area | Immunology |
| Phase | FDA-approved |
| First approval | 1969 |
Mechanism of action
. Mechanism of Action. The mechanism of action of doxepin in sleep maintenance is unclear; however, doxepins effect could be mediated through antagonism of the H1 receptor.
Approved indications
- Anxiety
- Atopic dermatitis
- Bipolar affective disorder, current episode depression
- Depressive disorder
- Insomnia
- Itching of skin
- Lichen simplex chronicus
- Severe major depression with psychotic features
Common side effects
- Nausea
- Vomiting
- Diarrhea
- Aphthous stomatitis
- Anorexia
- Indigestion
- Taste disturbances
- Hypotension
- Hypertension
- Tachycardia
- Skin rash
- Edema
Drug interactions
- duloxetine
- fluoxetine
- fluvoxamine
- isocarboxazid
- linezolid
- pargyline
- paroxetine
- phenelzine
- procarbazine
- quinidine
- rifabutin
- rifampicin
Key clinical trials
- Doxepin and a Topical Rinse in the Treatment of Acute Oral Mucositis Pain in Patients Receiving Radiotherapy With or Without Chemotherapy (PHASE3)
- Doxepin Solution for Alleviation of Stubborn Breakthrough Pain Induced by Swallowing in Patients Receiving Radiotherapy for Nasopharyngeal Carcinoma (NA)
- Characterization of the Toll-like Receptor 7-agonist Imiquimod 3.75% As a New Surrogate Model of Itch (NA)
- Longitudinal Comparative Effectiveness of Bipolar Disorder Therapies
- Stigma and Efficacy of Zhizhu Kuanzhong Capsules (NA)
- Characterization of New Human Models of Non-histaminergic Itch and Their Interaction With the TRPM8 Receptor (NA)
- Using Doxepin for Urticaria (PHASE3)
- Characterization of BAM8-22 as a New Surrogate Model of Non-histaminergic Itch (NA)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA label | Mechanism, indications, dosing, boxed warnings, drug interactions |
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |