Reacción a "The FDA approves a new type of drug for schizophrenia"

The most novel aspect is that, for the first time, an indication for schizophrenia will be given (since the use of chlorpromazine began in 1952!) to a drug that does not act directly on dopamine receptors. Despite this, the agonist mechanism of muscarinic receptors can, through two distinct pathways involving GABAergic and glutamatergic neurons, produce a decrease in dopaminergic activity in areas where dopaminergic hyperactivity has been implicated with psychotic symptoms. 

Regarding efficacy, the two phase III clinical trials have been robust and, more rarely, very consistent (effect size 0.6). As for side effects, it should be noted: 

1. Xanomeline was tested decades ago and was effective, but it was abandoned due to peripheral muscarinic side effects. Now, they have added a second substance (trospium), which blocks peripheral receptors to prevent those side effects. 
2. Since it does not have a direct dopaminergic effect, the typical side effects of the drugs (antidopaminergic or partial agonists) that we have used until now to treat schizophrenia/psychosis, such as extrapyramidal symptoms or hyperprolactinemia, do not appear or are greatly reduced.