Iloperidone, sold under the brand name Fanapt among others, is an atypical antipsychotic for the treatment of schizophrenia and bipolar I disorder.
Routes of administration-By mouth, injection
Atypical antipsychotic
Bioavailability 96% (oral; Tmax = 2–4 hours) Protein binding-97%
Metabolism- Hepatic (CYP2D6-mediated hydroxylation and CYP3A4-mediated O-demethylation)
Elimination half-life 18–33 hours
Excretion-urine (45.1–58.2%) and feces (19.9–22.1%)
Iloperidone is indicated for the treatment of schizophrenia and mania or mixed episodes in bipolar I disorder.
In a comparison of 15 antipsychotic drugs in effectivity in treating schizophrenic symptoms, iloperidone demonstrated mild effectiveness — as effective as lurasidone, and 13 to 15% less effective than ziprasidone, chlorpromazine, and asenapine.
It generally appears to work better than placebo.
Hypotension, dizziness, and somnolence were very common side effects ranging from mild to moderate in severity.
Repeat administration of iloperidone could decrease the effects of hypotension.
The approved dose is 12–24 mg.
A gradual taper when discontinuing this antipsychotics to avoid acute withdrawal symptoms or rapid relapse.
Symptoms of withdrawal commonly include nausea, vomiting, and loss of appetite, restlessness, increased sweating, and trouble sleeping.
Symptoms generally resolve after a short period of time.
There is evidence that discontinuation of antipsychotics can result in psychosis, and reoccurrence of the condition that is being treated.
Rarely tardive dyskinesia can occur when the medication is stopped.
Iloperidone works by acting upon and antagonizing specific neurotransmitters, particularly multiple dopamine and serotonin receptor subtypes.
It is considered an ‘atypical’ antipsychotic because it displays serotonin receptor antagonism, similar to other atypical antipsychotics.
The older typical antipsychotics are primarily dopamine antagonists.
Iloperidone has been shown to act as an antagonist at all tested receptors except for 5-HT2A.
It exhibits high (nM) affinity to serotonin 5-HT2A (Ki value of 5.6 nM) where it acts as an inverse agonist.
Antagonism occurs at all other receptors following dopamine D2 and D3 and α1-adrenergic receptors, moderate affinity for dopamine D4, serotonin 5-HT6, 5-HT7 and low affinity for the serotonin 5-HT1A, dopamine D1, and histamine H1 receptors.