Samidorphan versus naltrexone: What’s the difference?

Question from a Member: A new antipsychotic for schizophrenia or acute mania is Lybalvi™ [a combination of olanzapine and samidorphan]. Samidorphan is a mu-opioid receptor antagonist. The idea is that this will minimize metabolic syndrome. Sure to be expensive. Is there any reason to think it would be better than just adding naltrexone to olanzapine…