In October 2010, the FDA approved lurasidone for the acute treatment of schizophrenia at a dose of 40 or 80 mg/d administered once daily with food (Table 1).
Table 1
Lurasidone: Fast facts
| Brand name: Latuda |
| Indication: Schizophrenia in adults |
| Approval date: October 28, 2010 |
| Availability date: February 2011 |
| Manufacturer: Sunovion Pharmaceuticals, Inc. |
| Dosing forms: 40 mg and 80 mg tablets |
| Recommended dosage: Starting dose: 40 mg/d. Maximum dose: 80 mg/d |
How it works
Although the drug’s exact mechanism of action is not known, it is thought that lurasidone’s antipsychotic properties are related to its antagonism at serotonin 2A (5-HT2A) and dopamine D2 receptors.1
Similar to most other atypical antipsychotics, lurasidone has high binding affinity for 5-HT2A and D2. Lurasidone has also high binding affinity for 5-HT7, 5-HT1A, and α2C-adrenergic receptors, low affinity for α-1 receptors, and virtually no affinity for H1 and M1 receptors (Table 2). Activity on 5-HT7, 5-HT1A, and α2C-adrenergic receptors is believed to enhance cognition, and 5-HT7 is being studied for a potential role in mood regulation and sensory processing.2,3 Lurasidone’s low activity on α-1, H1, and M1 receptors suggests a low risk of orthostatic hypotension, H1-mediated sedation and weight gain, and H1- and M1-mediated cognitive blunting.
Pharmacokinetics
Lurasidone is absorbed in the gastrointestinal tract. It reaches maximum concentration (Cmax) in 1 to 3 hours. Cmax doubles when lurasidone is administered with food (≥350 calories), but absorption is independent of the meal’s fat content.4 After absorption, the drug is highly bound (99%) to serum proteins (albumin and α-1-glycoprotein). The elimination half-life is 18 hours and steady-state concentration is reached within 7 days.1 Lurasidone is eliminated predominantly through cytochrome P450 (CYP) 3A4 metabolism in the liver.
Efficacy
Lurasidone’s efficacy for treatment of acute schizophrenia was established in four 6-week, randomized placebo-controlled clinical trials.1 The patients were adults (mean age: 38.8; range: 18 to 72) who met DSM-IVTR criteria for schizophrenia, didn’t abuse drugs or alcohol, and had not taken any investigational drug for ≥1 month. Symptoms were measured on the Positive and Negative Syndrome Scale (PANSS); Brief Psychiatric Rating Scale as derived from the PANSS (BPRSd); and the Clinical Global Impressions-Severity scale (CGI-S).
In the first clinical trial, 145 patients were randomized to lurasidone, 40 mg/d or 120 mg/d, or placebo. Treatment with either dose of lurasidone was superior to treatment with placebo on the BPRSd (Least Squares Mean [LSM] difference from placebo in change from baseline: -5.6 on lurasidone 40 mg/d, -6.7 on lurasidone 120 mg/d) and CGI-S.1,5
The second trial randomized 180 patients to lurasidone, 80 mg/d, or placebo. Lurasidone, 80 mg/d, was superior to placebo as measured on the BPRSd (LSM difference from placebo in change from baseline: -4.7 on lurasidone 80 mg/d) and CGI-S.1,6
The third trial randomized 489 patients to lurasidone, 40 mg/d, 80 mg/d, 120 mg/d, or placebo. All lurasidone arms were superior to placebo on PANSS (LSM difference from placebo in change from baseline: -2.1 on 40 mg/d, -6.4 on 80 mg/d, and -3.5 on 120 mg/d) and CGI-S scores. This study also showed that lurasidone appears to have a rapid onset of action (day 3 to 4) and provides sustained improvement of symptoms.1
In the fourth trial, 473 individuals were randomized to lurasidone, 40 mg/d or 120 mg/d, olanzapine, 15 mg/d, or placebo. Olanzapine and both dosages of lurasidone were superior to placebo in improving PANSS scores (LSM difference from placebo in change from baseline: -9.7 on lurasidone 40 mg/d, -7.5 on lurasidone 120 mg/d, and -12.6 on olanzapine 15 mg/d) and CGI-S.1,7 Both doses of lurasidone were not superior to olanzapine but had less negative impact on lipid profile, weight gain, and glycemia.
Tolerability
Tolerability information is extracted from a clinical study database consisting of 2,096 patients with schizophrenia who participated in premarketing clinical trials and were exposed to single or multiple doses of lurasidone, 20 mg, 40 mg, 80 mg, or 120 mg.1 Overall, lurasidone was well tolerated. The rate of discontinuation from clinical trials because of adverse effects was 9.4% for lurasidone vs 5.9% for placebo. Somnolence, akathisia, nausea, parkinsonism, and agitation were the most commonly reported adverse reactions; somnolence and akathisia appear dose-related. Other adverse effects associated with lurasidone were nausea, vomiting, dyspepsia, dystonia, dizziness, insomnia, agitation, and anxiety (Table 2).
Metabolic changes (hyperlipidemia, hyperglycemia, and increased body weight) associated with cardiovascular risk in patients treated with atypical antipsychotics were studied in short-term placebo-controlled trials. Lurasidone is considered to be weight-neutral and does not have significant effects on serum lipids or glucose.2 As is the case with other D2 antagonists, lurasidone is associated with increased prolactin, which appears to be greater in females and is dose-dependent. Lurasidone is not associated with significant QTc prolongation, seizures, transaminases increase, or changes in serum chemistry, hematology, or urinalysis.