Prothiaden (dothiepin hydrochloride) is a tricyclic antidepressant (TCA) indicated for the management of major depressive disorder. It functions by inhibiting the reuptake of norepinephrine and serotonin, thereby increasing the availability of these neurotransmitters in the synaptic cleft. This mechanism aids in restoring mood balance and alleviating symptoms of depression. Prothiaden is recognized for its dual anxiolytic and antidepressant properties, making it a valuable option in clinical psychiatric practice. Proper diagnosis and supervision by a healthcare professional are essential prior to initiation.

Features

• Active ingredient: Dothiepin hydrochloride
• Available in 25 mg and 75 mg tablet formulations
• Belongs to the tricyclic antidepressant (TCA) class
• Exhibits both norepinephrine and serotonin reuptake inhibition
• Typically administered as a single daily dose, often at night
• Bioavailability is high following oral administration
• Metabolized hepatically via cytochrome P450 enzymes
• Half-life ranges between 14–24 hours

Benefits

• Provides effective relief from symptoms of major depressive disorder
• Reduces associated anxiety due to its sedative properties
• Helps restore normal sleep patterns in patients with depression-related insomnia
• May improve overall energy levels and daily functioning
• Supports long-term mood stabilization with consistent use
• Offers a well-established efficacy and safety profile within its class

Common use

Prothiaden is primarily prescribed for the treatment of major depressive episodes. It is also used off-label in certain cases for managing anxiety disorders, neuropathic pain, and as an adjunct in chronic pain syndromes. Its sedative effect makes it particularly useful for depressed patients presenting with significant insomnia or agitation. Treatment should always be initiated under specialist supervision following a thorough psychiatric assessment.

Dosage and direction

The initial adult dosage is typically 75 mg daily, usually administered as a single dose at bedtime. Depending on patient response and tolerance, this may be increased gradually to a maximum of 150 mg per day, though some severe cases may require up to 225 mg daily under close supervision. Elderly patients should start at a lower dose, such as 25–50 mg daily. Dosage adjustments must be made cautiously and under medical guidance. Tablets should be swallowed whole with water and not crushed or chewed.

Precautions

Patients should be monitored for worsening depression or emergence of suicidal ideation, especially at the beginning of treatment or after dosage changes. Use with caution in patients with cardiovascular disease, glaucoma, urinary retention, or a history of seizures. Avoid abrupt discontinuation to prevent withdrawal symptoms. Alcohol consumption should be avoided due to enhanced sedative effects. Regular liver function tests and blood counts may be advised during prolonged therapy.

Contraindications

Prothiaden is contraindicated in patients with known hypersensitivity to dothiepin or other TCAs. It must not be used concomitantly with monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing MAOI therapy. Additional contraindications include recent myocardial infarction, severe liver impairment, and certain cardiac arrhythmias. It is also contraindicated during the acute recovery phase after a heart attack.

Possible side effect

Common side effects may include dry mouth, drowsiness, constipation, blurred vision, and dizziness. Less frequently, patients may experience orthostatic hypotension, weight gain, sweating, or urinary retention. Serious side effects such as cardiac arrhythmias, seizures, or severe hyponatremia are rare but require immediate medical attention. Any allergic reaction, including rash or swelling, should be reported promptly.

Drug interaction

Prothiaden may interact with MAOIs, leading to serotonin syndrome. It can potentiate the effects of CNS depressants including alcohol, benzodiazepines, and opioids. Concurrent use with other serotonergic drugs (e.g., SSRIs, SNRIs) increases serotonin syndrome risk. Anticholinergic effects may be enhanced when used with other anticholinergic agents. Caution is advised with anticoagulants, anticonvulsants, and antihypertensive drugs. Always inform your prescriber of all medications being taken.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is almost time for the next scheduled dose. In that case, skip the missed dose and resume the usual dosing schedule. Do not double the dose to make up for a missed one. Consistent daily intake is important to maintain stable plasma concentrations.

Overdose

Overdose with Prothiaden can be severe and potentially fatal. Symptoms may include extreme drowsiness, agitation, confusion, tachycardia, hypotension, convulsions, coma, and cardiac arrhythmias. Management involves immediate medical attention, gastric lavage if presented early, activated charcoal, and supportive care including ECG monitoring. Specific treatments such as sodium bicarbonate for arrhythmias may be administered in a hospital setting.

Storage

Store at room temperature (15–30°C) in a dry place, protected from light and moisture. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging. Dispose of any unused medication safely in accordance with local regulations—do not flush or throw in household trash.

Disclaimer

This information is intended for educational purposes and does not replace professional medical advice. Always consult a qualified healthcare provider for diagnosis, treatment decisions, and personalized dosage recommendations. Do not initiate or discontinue Prothiaden without medical supervision.

Reviews

Clinical studies and long-term use support the efficacy of Prothiaden in treating moderate to severe depression. Many patients report significant improvement in mood, sleep, and overall quality of life after several weeks of consistent use. Some note initial side effects such as drowsiness, which often subside with continued treatment. It remains a trusted option among psychiatrists for patients who do not respond to newer antidepressants.