is donnatal a controlled substance
exists and is an alternate of. Merge this question into. Split and merge into it. Answer by Allansw. Confidence votes 8. Donnatal is a synonym for Phenobarbatal, a Controlled Substance Schedule IV. In Canada Donnatal is also a controlled substance.o. A controlled substance is one that may not be legally dispensed without a prescription or, in some cases, may not legally be possessed or dispensed at all.