Which pills you can crush or split

Because a list of drug names cannot express the answer. Metoprolol succinate extended-release is, in its label's own words, "scored and can be divided; however, do not crush or chew the whole or half tablet" — permitted and forbidden in the same sentence, depending on what you are doing to it. And the immediate-release version of the same drug is a different product with different instructions. Quoting the label keeps that intact; a name on a list loses it.

Because the coating or matrix is what meters the dose out over the day. Crush it and the entire day's dose is released at once — which for an opioid, a heart-rate drug or an ADHD stimulant is the difference between a dose and an overdose. That mechanism, not the molecule, is why the instruction exists.

It means none of the labels we read prints an instruction about crushing or splitting. Those pages exist and say so with the number of labels checked, but they are not submitted for indexing because the text is necessarily the same for every such drug. Absence of a restriction is also not a technique guide — an unscored tablet still splits unevenly.

Ask the prescriber or pharmacist before altering anything. Most drugs that cannot be crushed exist in another form — a liquid, a dispersible tablet, a patch, or an immediate-release version taken more often — and switching is usually straightforward.