Complex sentence: As the drug can be fatal in high doses, prescribing clomethiazole outside a controlled environment, like a hospital, is not recommended, especially because there are much less toxic alternatives, such as diazepam.
Split into simpler sentences: As the drug can be fatal in high doses, prescribing clomethiazole outside a controlled environment, like a hospital, is not recommendable. Especially because there are much less toxic alternatives, such as diazepam.