Iloperidone, commonly known as Fanapt and previously known as Zomaril, is an
atypical antipsychotic
The atypical antipsychotics (AAP), also known as second generation antipsychotics (SGAs) and serotonin–dopamine antagonists (SDAs), are a group of antipsychotic drugs (antipsychotic drugs in general are also known as major tranquilizers and ne ...
for the treatment of
schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdra ...
.
Medical uses
Iloperidone is indicated for the treatment of
schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdra ...
. In a 2013 study in a comparison of 15 antipsychotic drugs in effectivity in treating schizophrenic symptoms, iloperidone demonstrated mild effectiveness. As effective as
lurasidone
Lurasidone, sold under the trade name Latuda among others, is an antipsychotic medication used to treat schizophrenia and bipolar disorder. It is taken by mouth.
Common side effects include sleepiness, movement disorders, nausea, and diarrhea. ...
, and 13 to 15% less effective than
ziprasidone
Ziprasidone, sold under the brand name Geodon among others, is an atypical antipsychotic used to treat schizophrenia and bipolar disorder. It may be used by mouth and by injection into a muscle (IM). The IM form may be used for acute agitation ...
,
chlorpromazine
Chlorpromazine (CPZ), marketed under the brand names Thorazine and Largactil among others, is an antipsychotic medication. It is primarily used to treat psychotic disorders such as schizophrenia. Other uses include the treatment of bipolar dis ...
, and
asenapine
Asenapine, sold under the brand name Saphris among others, is an atypical antipsychotic medication used to treat schizophrenia and acute mania associated with bipolar disorder.
It was chemically derived via altering the chemical structure of the ...
.
It generally appears to work better than placebo.
Side effects
Examination of the safety and tolerability of iloperidone have shown that at a 5 mg/day dose in healthy male volunteers, the drug was fairly well tolerated, although
hypotension
Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the dias ...
, dizziness, and somnolence were very common side effects ranging from mild to moderate in severity. A second study showed that co administration of food decreased the severity of these effects. This study also indicated that repeat administration of iloperidone could decrease the effects of hypotension.
The approved dose is 12–24 mg not 5 mg. However, claims of better tolerance have been reported.
Discontinuation
The
British National Formulary
The ''British National Formulary'' (BNF) is a United Kingdom (UK) pharmaceutical reference book that contains a wide spectrum of information and advice on prescribing and pharmacology, along with specific facts and details about many medicines ...
recommends a gradual withdrawal when discontinuing antipsychotics to avoid acute withdrawal syndrome or rapid relapse.
Symptoms of withdrawal commonly include nausea, vomiting, and loss of appetite.
Other symptoms may include restlessness, increased sweating, and trouble sleeping.
[ Less commonly there may be a feeling of the world spinning, numbness, or muscle pains.][ Symptoms generally resolve after a short period of time.][
There is tentative evidence that discontinuation of antipsychotics can result in psychosis. It may also result in reoccurrence of the condition that is being treated. Rarely tardive dyskinesia can occur when the medication is stopped.][
]
Pharmacology
Iloperidone exerts its effects by acting upon and antagonizing specific neurotransmitters, particularly multiple dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic compound, organic chemical of the catecholamine and phenethylamine families. Dopamine const ...
and serotonin
Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vas ...
receptor subtypes. It is considered an ‘atypical’ antipsychotic because it displays serotonin receptor antagonism, similar to other atypical antipsychotics. The older typical antipsychotic
Typical antipsychotics (also known as major tranquilizers, and first generation antipsychotics) are a class of antipsychotic drugs first developed in the 1950s and used to treat psychosis (in particular, schizophrenia). Typical antipsychotics ma ...
s are primarily dopamine antagonists.
Iloperidone has been shown to act as an antagonist
An antagonist is a character in a story who is presented as the chief foe of the protagonist.
Etymology
The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...
at all tested receptors. It exhibits high (nM) affinity to serotonin 5HT2A (Ki value of 5.6 nM), dopamine D2 (6.3 nM) and D3 (7.1 nM) and noradrenaline α1 receptors (0.36 nM), moderate affinity for dopamine D4 (25 nM), serotonin 5HT6 (43 nM), 5HT7 (22 nM), and low affinity for the serotonin 5HT1A (168 nM), dopamine D1 and histamine H1 receptors. In addition, pharmacogenomic studies identified single nucleotide polymorphisms
In genetics, a single-nucleotide polymorphism (SNP ; plural SNPs ) is a germline substitution of a single nucleotide at a specific position in the genome. Although certain definitions require the substitution to be present in a sufficiently larg ...
associated with an enhanced response to iloperidone during acute treatment of schizophrenia.
History
Hoechst Marion Roussel Inc. made initial inquiries into the drug; however, in May 1996, they discontinued research, and in June 1997 gave research rights to Titan Pharmaceuticals. Titan then handed over worldwide development, manufacturing and marketing rights to Novartis
Novartis AG is a Swiss-American multinational pharmaceutical corporation based in Basel, Switzerland and
Cambridge, Massachusetts, United States (global research).name="novartis.com">https://www.novartis.com/research-development/research-loc ...
in August 1998. On June 9, 2004, Titan Pharmaceuticals announced that the Phase III development rights have been acquired by Vanda Pharmaceuticals. The original launch date was scheduled for 2002. On November 27, 2007, Vanda Pharmaceuticals announced that the U.S. Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
(FDA) had accepted their New Drug Application for iloperidone, confirming the application is ready for FDA review and approval. On July 28, 2008, the FDA issued a not-approvable letter to Vanda Pharmaceuticals concerning the drug, stating that further trials are required before a decision can be made concerning marketed usage of iloperidone.
Iloperidone was approved by the FDA for the treatment of schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdra ...
in the United States on May 6, 2009.
See also
* List of investigational anxiolytics
This is a list of investigational anxiolytics, or anxiolytics that are currently under development for clinical use but are not yet approved. Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in paren ...
* Lidanserin
Lidanserin (International Nonproprietary Name, INN; ZK-33,839) is a drug which acts as a combined 5-HT2A receptor, 5-HT2A and α1-adrenergic receptor, α1-adrenergic receptor receptor antagonist, antagonist. It was developed as an antihypertensiv ...
References
External links
Fanapt Prescribing Information
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Pharmacodynamics (PD) is the study of the biochemical and physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or combinations of organisms (fo ...
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