We welcome Dr Silva's comments and as indicated in our editorial, we share his enthusiasm for the use of intramuscular clozapine – albeit with caution, given its unlicensed status, the absence of any prospective studies with longer follow-up periods and the logistical difficulties with its administration.

We prefaced some of our observations about prescribing intramuscular clozapine with ‘however’ simply to draw attention to the fact that most of the patients in Casetta's study did not, in fact, receive any intramuscular clozapine, since they opted to take oral clozapine instead. We left it to our readers to draw their own conclusions regarding the differences between prescribed as distinct from administered intramuscular clozapine.

We're intrigued as to Dr Silva's source of free clozapine. Our sources indicate that a pack of ten 5 mL ampoules (25 mg/mL) cost £759.33 plus VAT.