Sulpiride: An Antipsychotic Drug

Sulpiride is an antipsychotic or neuroleptic drug. It has a benzodiazepine structure and is classified as a dopamine receptor antagonist. Dopamine is a fundamental neurotransmitter in the nervous system. In fact, it regulates a large number of responses in the body.

Dopamine is especially important in motor function since it regulates body movements. Furthermore, it acts on emotional responses and sensations, as well as cognition and behavior, among others.

High dopamine levels are associated with mental illnesses, such as schizophrenia or psychoses. For this reason, many antipsychotic drugs are antidopaminergic and block the effects of this neurotransmitter.

Sulpiride has proven to be a highly effective drug in various psychological disorders. For example, it’s effective in the treatment of psychosomatic syndromes, senile dementia, gastrointestinal somatizations, and dizziness.

The uses of sulpiride

The therapeutic use of this drug as included in the technical data sheet of this medicine are as follows:

Treatment of depressive disorders with psychotic symptoms in combination with antidepressants. This is in cases where antidepressants alone have proven to be ineffective.
Other severe forms of depression that prove resistant to antidepressants.
Treatment of acute and chronic psychoses.
Treatment of vertigo in cases in which there’s no response to the usual antivertiginous treatment.

As we mentioned earlier, sulpiride is an antipsychotic drug. However, it’s not only used to treat mental disorders. In fact, it’s also useful for treating certain neurological diseases. Furthermore, it’s been shown to be effective in treating vertigo. This is a symptom that affects approximately 23 percent of the general population. Indeed, it’s a frequent reason for consultation in primary care. Generally, its prevalence tends to increase with age.

Vertigo is a hallucinatory sensation of movement produced by an alteration of orientation in space. Its origin is usually in the structures of the inner ear or at some point in the vestibular pathway of the central nervous system.

Mechanism of action

Sulpiride acts as a specific antagonist of dopamine D2 and D3 receptors. Its effect depends mainly on the administered dose, which should always be prescribed and controlled by the doctor.

At low doses, it has an effect on psychotic disorders with negative symptoms. However, it has hardly any effect on positive symptoms. Nevertheless, at higher doses, it can improve positive symptoms in patients with acute or chronic psychoses. Extremely high doses of sulpiride can have sedative effects.

Regarding its antivertiginous action, sulpiride blocks D2 receptors in the chemoreceptor trigger area. This means it inhibits vomiting. It also acts on the regulatory mechanisms of balance and the sense of spatial orientation.

Sulpiride has a powerful vestibular suppressive effect. In fact, it’s especially useful in the symptomatic treatment of nausea and vomiting that can accompany vertigo and motion sickness. It’s generally administered orally. However, in the most severe cases, it can also be administered intramuscularly.

Woman with puerperal psychosis

Side effects

The most common side effects of sulpiride are:

Insomnia.
Sedation or drowsiness
Extrapyramidal disorder.
Parkinsonism symptoms.
Shaking.
Hyperprolactinemia.
Constipation.
Increased liver enzymes.
Chest pain.
Weight gain.
Galactorrhea.

It’s important to notify the doctor of any adverse reactions that are experienced during treatment with this drug. Furthermore, to avoid interactions, its administration shouldn’t be combined with antiparkinsonian or antiarrhythmic drugs. Likewise, to avoid unwanted effects, the dosage and duration of treatment indicated by the specialist must always be respected.

In the case of overdose, there’s no specific antidote for sulpiride. In this case, treatment would be symptomatic and would involve controlling cardiac function. On the other hand, in the case of extrapyramidal symptoms, anticholinergic drugs would be administered.