Prothipendyl

Prothipendyl is a weak acting tricyclic azaphenothiazine neuroleptic. It is used to treat agitation and agitation in patients with underlying psychiatric disorders. Indications for prothipendyl include dementia, depression, schizophrenia, anxiety, and psychosomatic disorders. It is also often used in the treatment of difficulty falling asleep because, unlike common benzodiazepines, it does not carry the potential for dependence.

Prothipendyl was first synthesized by Wilhelm Schuler.

Pharmacodynamics

Prothipendyl is a dopamine antagonist with high selectivity for D1 and D2 receptors. In addition, it has a low affinity for serotonin receptors of the 5-HT2A type. In higher doses, the drug has a sleep-inducing effect due to its sedative-hypnotic action. In addition to antipsychotic effects, prothipendyl also has antihistaminergic, antiemetic, and sedative properties.

Pharmacokinetics

The bioavailability of prothipendyl after oral administration is approximately 15%. Maximum plasma concentration is reached after approximately 1 h. The plasma half-life is around 2-3 hours. The substance is metabolized in the liver and excreted mainly in the urine.

Drug interactions

When taken concomitantly with drugs that have a depressant effect on the CNS, there may be a mutual enhancement of effect.

These include:

• Benzodiazepines
• Sedatives
• Antihistamines
• Alcohol
• Antihypertensives

The effects of levodopa may be attenuated if taken concomitantly. Prothipendyl may counteract the vasoconstrictor effects of epinephrine and phenylephrine.

Side effects

Possible side effects are:

• Lowered blood pressure
• Circulatory weakness
• Vertigo
• Tachycardia

Less common side effects include weight gain, circulatory collapse, arrhythmias (including QT-time prolongation), leukopenia, epilepsy, dry mouth, photosensitivity, priapism, and amenorrhea.

Contraindications

• Alcohol intoxication
• Sedatives
• Analgesics
• Coma
• Pregnancy and lactation