1. Clinical Overview
A fixed-dose combination of a thioxanthene neuroleptic (flupenthixol) and a tricyclic antidepressant (melitracen). It is primarily used in the management of mild to moderate depression and anxiety, particularly when associated with psychosomatic disorders, apathy, and withdrawal. The combination is believed to provide a balanced effect, with flupenthixol counteracting agitation and melitracen elevating mood, while minimizing the side effect profile of each individual component.
| Onset | Duration | Bioavailability |
|---|---|---|
| Initial effects on anxiety and agitation may be seen within 3-5 days. Full antidepressant effect typically requires 2-4 weeks of continuous therapy. | The therapeutic effect is sustained with once or twice daily dosing due to the long half-life of flupenthixol. | Flupenthixol: Approximately 40-55% (oral). Melitracen: Well absorbed, but specific percentage data is limited; typical for tricyclics. |
2. Mechanism of Action
The combination works via complementary mechanisms. Flupenthixol is a potent dopamine D1/D2 receptor antagonist with mild anticholinergic and sedative properties. Melitracen is a tricyclic antidepressant that inhibits the reuptake of norepinephrine and serotonin (5-HT) in the central nervous system, thereby increasing their synaptic concentrations. The net effect is a modulation of mood, drive, and anxiety with a lower incidence of side effects compared to higher doses of either drug alone.
3. Indications & Uses
- Mild to moderate depression
- Mixed anxiety and depressive disorder (MADD)
- Dysthymia
- Depression with associated anxiety, apathy, or psychomotor retardation
4. Dosage & Administration
Adult Dosage: Initially, 1 tablet (Flupenthixol 0.5mg + Melitracen 10mg) once daily in the morning or evening. May be increased to 1 tablet twice daily (morning and noon/evening) based on response and tolerance. Maximum: 3 tablets per day in divided doses.
Administration: Administer with or without food. Swallow whole with a glass of water. Avoid taking late in the evening if it causes insomnia. Do not crush or chew. Consistent daily timing is recommended.
5. Side Effects
Common side effects may include:
- Dry mouth
- Constipation
- Blurred vision (accommodation disturbance)
- Drowsiness or sedation (usually transient)
- Dizziness
- Increased sweating
- Weight gain
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Monoamine Oxidase Inhibitors (MAOIs) - e.g., Phenelzine, Selegiline | Risk of serotonin syndrome, hyperpyrexia, convulsions, death. | Contraindicated |
| Other CNS Depressants (Alcohol, Benzodiazepines, Opioids) | Additive sedation, impaired psychomotor performance, respiratory depression. | Major |
| Anticholinergic drugs (e.g., Atropine, Trihexyphenidyl, TCAs) | Increased anticholinergic side effects (dry mouth, constipation, urinary retention, confusion). | Moderate |
| Antihypertensives (especially alpha-blockers, guanethidine) | Potentiation of hypotensive effect. | Moderate |
| QT-prolonging drugs (e.g., Class IA/III antiarrhythmics, Macrolides, Fluoroquinolones) | Increased risk of torsades de pointes. | Major |
| SSRIs/SNRIs (e.g., Fluoxetine, Paroxetine) | Increased plasma levels of TCA (melitracen) via CYP2D6 inhibition, risk of serotonin syndrome. | Moderate to Major |
| Sympathomimetics (e.g., Adrenaline, Noradrenaline) | Enhanced pressor response, risk of arrhythmias. | Moderate |
| Warfarin | Melitracen may potentiate anticoagulant effect; monitor INR closely. | Moderate |
7. Patient Counselling
- DO take the medicine at the same time(s) each day.
- DO continue taking even if you feel better, unless advised by your doctor. Stopping suddenly can cause relapse or withdrawal.
- DO inform all your doctors and dentists you are on this medicine.
- DO get up slowly from sitting/lying position to avoid dizziness.
- DONT consume alcohol.
- DONT take any other prescription, OTC, or herbal medicine without consulting your doctor.
- DONT drive or operate heavy machinery if you feel drowsy or dizzy.
- DONT stop the medication abruptly.
8. Toxicology & Storage
Overdose: Symptoms are a combination of TCA and neuroleptic overdose: Severe CNS depression (coma), seizures, cardiac disturbances (tachycardia, arrhythmias, prolonged QRS/QT, hypotension), anticholinergic crisis (hyperthermia, flushed skin, mydriasis, ileus), extrapyramidal symptoms, neuroleptic malignant syndrome features. Risk of death from cardiac arrest or respiratory failure.
Storage: Store below 30°C, in a cool, dry place, protected from light and moisture. Keep in the original blister pack or container. Keep out of reach and sight of children. Do not use after the expiry date printed on the pack.