Amisulpride is indicated for use in the United States in adults for the prevention of postoperative nausea and vomiting (PONV), either alone or in combination with an antiemetic of a different class; and to treat PONV in those who have received antiemetic prophylaxis with an agent of a different class or have not received prophylaxis.[9]
Amisulpride is believed to work by blocking, or antagonizing, the dopamine D2 receptor, reducing its signalling. The effectiveness of amisulpride in treating dysthymia and the negative symptoms of schizophrenia is believed to stem from its blockade of the presynaptic dopamine D2 and D3autoreceptors. These presynaptic receptors regulate the release of dopamine into the synapse, so by blocking them amisulpride increases dopamine concentrations in the synapse. This increased dopamine concentration is theorized to act on dopamineD1 receptors to relieve depressive symptoms (in dysthymia) and the negative symptoms of schizophrenia.[11]
Although according to other studies it appears to have comparable efficacy to olanzapine in the treatment of schizophrenia,[16] amisulpride augmentation, similarly to sulpiride augmentation, has been considered a viable treatment option (although this is based on low-quality evidence) in clozapine-resistant cases of schizophrenia.[17][18] Another recent study concluded that amisulpride is an appropriate first-line treatment for the management of acute psychosis.[19]
Amisulpride is indicated for use in the United States in adults for the prevention of postoperative nausea and vomiting (PONV), either alone or in combination with an antiemetic of a different class; and to treat PONV in those who have received antiemetic prophylaxis with an agent of a different class or have not received prophylaxis.[9]
Hyperprolactinaemia (which can lead to galactorrhoea, breast enlargement and tenderness, sexual dysfunction, etc.)
Weight gain (produces less weight gain than chlorpromazine, clozapine, iloperidone, olanzapine, paliperidone, quetiapine, risperidone, sertindole, zotepine and more (although not statistically significantly) weight gain than haloperidol, lurasidone, ziprasidone and approximately as much weight gain as aripiprazole and asenapine)[13]
Anticholinergic side effects (although it does not bind to the muscarinic acetylcholine receptors and hence these side effects are usually quite mild) such as
QT interval prolongation (in a recent meta-analysis of the safety and efficacy of 15 antipsychotic drugs amisulpride was found to have the 2nd highest effect size for causing QT interval prolongation[13])
Hyperprolactinaemia results from antagonism of the D2 receptors located on the lactotrophic cells found in the anterior pituitary gland. Amisulpride has a high propensity for elevating plasma prolactin levels as a result of its poor blood–brain barrier penetrability and hence the resulting greater ratio of peripheral D2 occupancy to central D2 occupancy. This means that to achieve the sufficient occupancy (~60–80%[32]) of the central D2 receptors in order to elicit its therapeutic effects a dose must be given that is enough to saturate peripheral D2 receptors including those in the anterior pituitary.[33][34]
Discontinuation
The British National Formulary recommends a gradual withdrawal when discontinuing antipsychotics to avoid acute withdrawal syndrome or rapid relapse.[35] Symptoms of withdrawal commonly include nausea, vomiting, and loss of appetite.[36] Other symptoms may include restlessness, increased sweating, and trouble sleeping.[36] Less commonly there may be a feeling of the world spinning, numbness, or muscle pains.[36] Symptoms generally resolve after a short period of time.[36]
There is tentative evidence that discontinuation of antipsychotics can result in psychosis.[37] It may also result in reoccurrence of the condition that is being treated.[38] Rarely tardive dyskinesia can occur when the medication is stopped.[36]
Overdose
Torsades de pointes is common in overdose.[39][40] Amisulpride is moderately dangerous in overdose (with the TCAs being very dangerous and the SSRIs being modestly dangerous).[41][42]
Amisulpride and its relatives sulpiride, levosulpiride, and sultopride have been shown to bind to the high-affinity GHB receptor at concentrations that are therapeutically relevant (IC50Tooltip Half-maximal inhibitory concentration = 50 nM for amisulpride).[45]
Amisulpride, sultopride and sulpiride respectively present decreasing in vitro affinities for the D2 receptor (IC50 = 27, 120 and 181 nM) and the D3 receptor (IC50 = 3.6, 4.8 and 17.5 nM).[47]
Though it was long widely assumed that dopaminergic modulation is solely responsible for the respective antidepressant and antipsychotic properties of amisulpride, it was subsequently found that the drug also acts as a potent antagonist of the serotonin5-HT7 receptor (Ki = 11.5 nM).[44] Several of the other atypical antipsychotics such as risperidone and ziprasidone are potent antagonists at the 5-HT7 receptor as well, and selective antagonists of the receptor show antidepressant properties themselves. To characterize the role of the 5-HT7 receptor in the antidepressant effects of amisulpride, a study prepared 5-HT7 receptor knockout mice.[44] The study found that in two widely used rodent models of depression, the tail suspension test, and the forced swim test, those mice did not exhibit an antidepressant response upon treatment with amisulpride.[44] These results suggest that 5-HT7 receptor antagonism mediates the antidepressant effects of amisulpride.[44]
Amisulpride also appears to bind with high affinity to the serotonin 5-HT2B receptor (Ki = 13 nM), where it acts as an antagonist.[44] The clinical implications of this, if any, are unclear.[44] In any case, there is no evidence that this action mediates any of the therapeutic effects of amisulpride.[44]
Amisulpride shows stereoselectivity in its actions.[48] Aramisulpride ((R)-amisulpride) has higher affinity for the 5-HT7 receptor (Ki = 47 nM vs. 1,900 nM) while esamisulpride ((S)-amisulpride) has higher affinity for the D2 receptor (4.0 nM vs. 140 nM).[48][49]
Through a high direct unmetabolized excretion, it has, despite its high usual dose, also high affinity for dopamine-D2-D3-receptors. Also the available literature gives us hints about also relatively high receptor dissociation kinetics (through a delayed but high occupancy at dopamine receptors after 6 hours from a 100 mg exposure). Moreover, this dopamine exposure could be slightly more "balanced" providing some little advantages over haloperidol in using it for drug exposure. Due to its lack of compensatory serotonin effects and also not having an anticholinergic profile, it may not considered as an effective alternative if akathasia is a problem.[5][34][50]
The U.S. Food and Drug Administration (FDA) approved a 10 mg/4mL amisulpride IV formulation for use in post-operative nausea based on evidence from four clinical trials of 2323 subjects undergoing surgery or experiencing nausea and vomiting after the surgery.[51] The trials were conducted at 80 sites in the United States, Canada and Europe.[51]
Two trials (Trials 1 and 2) enrolled subjects scheduled to have surgery.[51] Subjects were randomly assigned to receive either amisulpride or a placebo drug at the beginning of general anesthesia.[51] In Trial 1, subjects received amisulpride or placebo alone, and in Trial 2, they received amisulpride or placebo in combination with one medication approved for prevention of nausea and vomiting.[51] Neither the subjects nor the health care providers knew which treatment was being given until after the trial was complete.[51]
The trials counted the number of subjects who had no vomiting and did not use additional medications for nausea or vomiting in the first day (24 hours) after the surgery.[51] The results then compared amisulpride to placebo.[51]
The other two trials (Trials 3 and 4) enrolled subjects who were experiencing nausea and vomiting after surgery.[51] In Trial 3, subjects did not receive any medication to prevent nausea and vomiting before surgery and in Trial 4 they received the medication, but the treatment did not work.[51] In both trials, subjects were randomly assigned to receive either amisulpride or placebo.[51] Neither the subjects nor the health care providers knew which treatment was being given until after the trial was complete.[51]
The trials counted the number of subjects who had no vomiting and did not use additional medications for nausea or vomiting in the first day (24 hours) after the treatment.[51] The trial compared amisulpride to placebo.[51]
The FDA has not approved amisulpride for use in any psychiatric indication. LB Pharmaceuticals is developing N-methyl amisulpride for the use in the treatment of schizophrenia; a Phase 2 first-in-patient study is planned for 2023.[52]
Amisulpride is not approved by the Food and Drug Administration for use in the United States in psychiatric indications, but it is approved and in use throughout Europe,[54] Asia, Mexico, New Zealand and Australia[6] to treat psychosis and schizophrenia.[55][56]
An IV formulation of Amisulpride was approved for the treatment of postoperative nausea and vomiting ("PONV") in the United States in February 2020.[57][9][51]
Research
Bipolar depression
SEP-4199 (non-racemic amisulpride), an 85:15 ratio of aramisulpride ((R)-amisulpride) to esamisulpride ((S)-amisulpride), which is theorized to provide more balanced serotonin5-HT7 and dopamineD2 receptorantagonism than racemic amisulpride (a 50:50 ratio of its (R)- and (S)-enantiomers), is or was under development by Sunovion Pharmaceuticals for the treatment of bipolar depression in the United States and other countries.[58][59][60] However, its development may have been discontinued.[58][59]
^ abcdefgRosenzweig P, Canal M, Patat A, Bergougnan L, Zieleniuk I, Bianchetti G (January 2002). "A review of the pharmacokinetics, tolerability and pharmacodynamics of amisulpride in healthy volunteers". Human Psychopharmacology. 17 (1): 1–13. doi:10.1002/hup.320. PMID12404702. S2CID23877366.
^ abc"Amisulpride". AdisInsight. 24 October 2021. Retrieved 24 October 2024.
^ abcdPani L, Gessa GL (2002). "The substituted benzamides and their clinical potential on dysthymia and on the negative symptoms of schizophrenia". Mol Psychiatry. 7 (3): 247–253. doi:10.1038/sj.mp.4001040. PMID11920152.
^ abcdRossi S, ed. (2013). Australian Medicines Handbook (2013 ed.). Adelaide: The Australian Medicines Handbook Unit Trust. ISBN978-0-9805790-9-3.
^ abcLeucht S, Cipriani A, Spineli L, Mavridis D, Orey D, Richter F, et al. (September 2013). "Comparative efficacy and tolerability of 15 antipsychotic drugs in schizophrenia: a multiple-treatments meta-analysis". Lancet. 382 (9896): 951–962. doi:10.1016/S0140-6736(13)60733-3. PMID23810019. S2CID32085212.
^Montgomery SA (December 2002). "Dopaminergic deficit and the role of amisulpride in the treatment of mood disorders". Int Clin Psychopharmacol. 17 Suppl 4: S9–15, discussion S16–7. PMID12685917.
^ abNatesan S, Reckless GE, Barlow KB, Nobrega JN, Kapur S (October 2008). "Amisulpride the 'atypical' atypical antipsychotic--comparison to haloperidol, risperidone and clozapine". Schizophrenia Research. 105 (1–3): 224–235. doi:10.1016/j.schres.2008.07.005. PMID18710798. S2CID11315672.
^Joint Formulary Committee, ed. (March 2009). "4.2.1". British National Formulary (57 ed.). United Kingdom: Royal Pharmaceutical Society of Great Britain. p. 192. ISBN978-0-85369-845-6. Withdrawal of antipsychotic drugs after long-term therapy should always be gradual and closely monitored to avoid the risk of acute withdrawal syndromes or rapid relapse.
^Isbister GK, Balit CR, Macleod D, Duffull SB (August 2010). "Amisulpride overdose is frequently associated with QT prolongation and torsades de pointes". Journal of Clinical Psychopharmacology. 30 (4): 391–395. doi:10.1097/JCP.0b013e3181e5c14c. PMID20531221. S2CID205710487.
^Joy JP, Coulter CV, Duffull SB, Isbister GK (August 2011). "Prediction of torsade de pointes from the QT interval: analysis of a case series of amisulpride overdoses". Clinical Pharmacology and Therapeutics. 90 (2): 243–245. doi:10.1038/clpt.2011.107. PMID21716272. S2CID26412012.
^ abcTaylor D, Paton C, Shitij K (2012). Maudsley Prescribing Guidelines in Psychiatry (11th ed.). West Sussex: Wiley-Blackwell. ISBN978-0-47-097948-8.
^Roth BL, Driscol J. "PDSP Ki Database". Psychoactive Drug Screening Program (PDSP). University of North Carolina at Chapel Hill and the United States National Institute of Mental Health. Retrieved 14 August 2017.
^ abMaitre M, Ratomponirina C, Gobaille S, Hodé Y, Hechler V (April 1994). "Displacement of [3H] gamma-hydroxybutyrate binding by benzamide neuroleptics and prochlorperazine but not by other antipsychotics". European Journal of Pharmacology. 256 (2): 211–214. doi:10.1016/0014-2999(94)90248-8. PMID7914168.
^Schoemaker H, Claustre Y, Fage D, Rouquier L, Chergui K, Curet O, et al. (January 1997). "Neurochemical characteristics of amisulpride, an atypical dopamine D2/D3 receptor antagonist with both presynaptic and limbic selectivity". The Journal of Pharmacology and Experimental Therapeutics. 280 (1): 83–97. PMID8996185.
^Blomme A, Conraux L, Poirier P, Olivier A, Koenig JJ, Sevrin M, et al. (2000). "Amisulpride, Sultopride and Sulpiride: Comparison of Conformational and Physico-Chemical Properties". Molecular Modeling and Prediction of Bioactivity. Springer US. pp. 404–405. doi:10.1007/978-1-4615-4141-7_97. ISBN978-1-4613-6857-1.
^ ab"Active substance: amisulpride"(PDF). 28 September 2017. EMA/658194/2017; Procedure no.: PSUSA/00000167/201701. Archived from the original(PDF) on 15 June 2018. Retrieved 26 February 2020.
^Lecrubier Y, Azorin M, Bottai T, Dalery J, Garreau G, Lempérière T, et al. (2001). "Consensus on the Practical Use of Amisulpride, an Atypical Antipsychotic, in the Treatment of Schizophrenia". Neuropsychobiology. 44 (1): 41–46. doi:10.1159/000054913. PMID11408792. S2CID21103201.
^ abWu J, Kwan AT, Rhee TG, Ho R, d'Andrea G, Martinotti G, et al. (2023). "A narrative review of non-racemic amisulpride (SEP-4199) for treatment of depressive symptoms in bipolar disorder and LB-102 for treatment of schizophrenia". Expert Rev Clin Pharmacol. 16 (11): 1085–1092. doi:10.1080/17512433.2023.2274538. PMID37864424.