Sulpiride

Sulpiride

Systematic (IUPAC) name
(±)-5-(aminosulfonyl)-N-[(1-ethylpyrrolidin-2-yl)methyl]-2-methoxybenzamide
Clinical data
Trade names	Dolmatil, Sulparex (discontinued), Sulpor
AHFS/Drugs.com	International Drug Names
Legal status	POM (UK) Rx-only
Routes	Oral
Pharmacokinetic data
Bioavailability	25–40%[1][2]
Protein binding	<40%[1]
Metabolism	Not metabolised[3]
Half-life	6-8 hours[1]
Excretion	Renal (70-90%),[2] Faecal (~95% as the unchanged drug)[1]
Identifiers
CAS number	15676-16-1 Y
ATC code	N05AL01
PubChem	CID 5355
IUPHAR ligand	5501
DrugBank	DB00391
ChemSpider	5162 Y
UNII	7MNE9M8287 Y
KEGG	D01226 Y
ChEMBL	CHEMBL26 Y
Chemical data
Formula	C15H23N3O4S
Mol. mass	341.427 g/mol
SMILES O=S(=O)(N)c1cc(c(OC)cc1)C(=O)NCC2N(CC)CCC2
InChI InChI=1S/C15H23N3O4S/c1-3-18-8-4-5-11(18)10-17-15(19)13-9-12(23(16,20)21)6-7-14(13)22-2/h6-7,9,11H,3-5,8,10H2,1-2H3,(H,17,19)(H2,16,20,21) Y Key:BGRJTUBHPOOWDU-UHFFFAOYSA-N Y
Y (what is this?)  (verify)

Sulpiride (sold as Dogmatil (HK, SG, PH), Dolmatil (IE, UK), Eglonyl (RU, ZA), Espiride (ZA), Modal (IL), Sulpor (UK), many others) is an atypical antipsychotic drug (although some texts have referred to it as a typical antipsychotic^[4]) of the benzamide class used mainly in the treatment of psychosis associated with schizophrenia and major depressive disorder. Sulpiride is more commonly used in Europe, Russia and Japan. Levosulpiride is its purified levo- isomer and is sold in India for similar purpose. So far it has not been approved in the United States, Canada and Australia. The drug has strong chemical and clinical similarities to the related antipsychotic amisulpride.

Medical uses

Sulpiride's primary use in medicine is in the management of the symptoms of schizophrenia.^[1] It has been used as both a monotherapy and adjunctive therapy (in case of treatment-resistance) in schizophrenia.^{[1][5][6][7][8][9]} It has also been used in the treatment of dysthymia.^[10] Augmentation with sulpiride has also been tried as a strategy for accelerating antidepressant response in patients with major depressive disorder.^[11] There is also evidence of its efficacy in treating panic disorder.^[12][13]

Pregnancy and lactation

• Pregnancy: Animal studies did not reveal any embryotoxicity or fetotoxicity, nor did limited human experience. Due to insufficient human data, pregnant women should be treated with sulpiride only if strictly indicated. Additionally, the newborns of treated women should be monitored, because isolated cases of extrapyramidal side effects have been reported.^[1]
• Lactation: Sulpiride is found in the milk of lactating women. Since the consequences are unclear, women should not breastfeed during treatment.^[1]

Adverse effects

Sulpiride is usually well-tolerated, producing few adverse effects. Their incidences are as follows:^{[1][5][14][15][16][17][18][19][20]}

Common (>1%) adverse effects

• Dizziness
• Headache
• Extrapyramidal side effects

- Tremor

- Dystonia

- Akathisia — a sense of inner restlessness that presents itself with the inability to stay still.

- Parkinsonism

• Somnolence (not a very prominent adverse effect considering its lack of alpha-1 adrenergic, histamine and muscarinic acetylcholine receptor affinity)
• Insomnia
• Weight gain or loss
• Hyperprolactinaemia (elevated plasma levels of the hormone, prolactin which can, in turn lead to sexual dysfunction, galactorrhoea, amenorrhoea, gynaecomastia, etc.)
• Nausea
• Vomiting
• Nasal congestion
• Anticholinergic adverse effects such as:

- Dry mouth

- Constipation

- Blurred vision

• Restlessness
• Impaired concentration

Rare (<1% incidence) adverse effects

• Tardive dyskinesia — a rare, often permanent movement disorder that, more often than not, results from prolonged treatment with antidopaminergic agents such as antipsychotics. It presents with slow (hence tardive), involuntary, repetitive and purposely movements that most often affect the facial muscles.
• Neuroleptic malignant syndrome — a rare, life-threatening complication that results from the use of antidopaminergic agents. Its incidence increases with concomitant use of lithium (medication) salts.
• Blood dyscrasias — rare, sometimes life-threatening complications of the use of a number of different antipsychotics (most notably clozapine) which involves abnormalities in the composition of a person's blood (e.g. having too few white blood cells per unit volume of blood. Examples include:

- Agranulocytosis — a significant drop in white blood cell count, leaving individuals wide open to life-threatening opportunistic infections.

- Neutropaenia

- Leucopenia

- Leukocytosis^[21]

• Seizures
• Torsades de Pointes

Unknown incidence adverse effects include

• QTc interval prolongation which can lead to potentially fatal arrhythmias.
• Cholestatic jaundice^[22]
• Elevated liver enzymes
• Primary biliary cirrhosis^[23]
• Allergic reactions
• Photosensitivity — sensitivity to light.
• Skin rashes
• Depression
• Catatonia
• Palpitations
• Agitation
• Diaphoresis — sweating without a precipitating factor (e.g. increased ambient temperature).
• Hypotension — low blood pressure.
• Hypertension — high blood pressure.
• Venous thromboembolism (probably rare)

Contraindications and cautions

Contraindications^[1]

• Hypersensitivity to sulpiride
• Pre-existing breast cancer or other prolactin-dependent tumors
• Phaeochromocytoma
• Intoxication with other centrally active drugs
• Concomitant use of levodopa
• Acute porphyria
• Comatose state or CNS depression
• Bone-marrow suppression

Cautions^[1]

• Pre-existing Parkinson's Disease
• Patients below 18 years of age (insufficient clinical data)
• Pre-existing severe heart disease/bradycardia, or hypokalemia (predisposing to long QT syndrome and severe arrhythmias)
• Patients with pre-existing epilepsy. Anticonvulsant therapy should be maintained.
• Lithium use — increased risk of neurological side effects of both drugs

Overdose

Sulpiride has a relatively low order of acute toxicity. Substantial amounts may cause severe but reversible dystonic crises with torticollis, protrusion of the tongue, and/or trismus. In some cases all the classical symptoms typical of severe Parkinson's Disease may be noted; in others, over-sedation/coma may occur. The treatment is largely symptomatic. Some or all extrapyramidal reactions may respond to the application of anticholinergic drugs such as biperiden or benztropine. All patients should be closely monitored for signs of long-QT syndrome and severe arrhythmias.

Chemistry

Sulpiride can be synthesized from 5-aminosulfosalicylic acid. Methylating this with dimethylsulfate gives 2-methoxy-5-aminosulfonylbenzoic acid, which is transformed into an amide using 2-aminomethyl-1-ethylpyrrolidine as the amine component and carbonyldiimidazole (CDI) as a condensing agent.^{[24][25][26][27][28]}

Pharmacology

Sulpiride is a selective antagonist at dopamine D₂ and D₃ receptors. This action dominates in doses exceeding 600 mg daily. In doses of 600 to 1,600 mg sulpiride shows mild sedating and antipsychotic activity. Its antipsychotic potency compared to chlorpromazine is only 0.2 (1/5). In low doses (in particular 50 to 200 mg daily) its prominent feature is antagonism of presynaptic inhibitory dopamine receptors accounting for some antidepressant activity and a stimulating effect. Therefore, it is in these doses used as a second line antidepressant. Additionally, it alleviates vertigo.

The benzamide neuroleptics (including sulpiride, amisulpride, and sultopride) have been shown to activate the endogenous gamma-hydroxybutyrate receptor in vivo at therapeutic concentrations.^[29] Sulpiride was found in one study in rats to upregulate GHB receptors.^[30] GHB has neuroleptic properties and it is believed binding to this receptor may contribute to the effects of these neuroleptics.

Sulpiride, along with clozapine, has been found to activate DNA demethylation in the brain.^[31]

See also

• Atypical antipsychotic
• Benzamide

References