In an ideal world the one remedy, the simillimum, would work for both chronic and acute problems. Sometimes this is the case, but often it is not, especially when treatment is in its early stages of a multimiasmatic case.

Additional points for consideration in acute prescribing:

We have more than the 6-200 range of potencies at our disposal and sometimes the higher potencies 1M - CM are needed even in acutes, depending on the dynamic of the disease process for that individual.

Some remedies have characteristics peculiar to them that fall outside the usual prescribing strategies: e.g. Baptisia is said to work better in low potency for flu, and to be repeated often. e.g. Ferrum Phos is to be remembered in acutes with no clear indications. Arsenicum is said to need to be repeated before it's apparent in order to work in urgent cases, and so forth.

When we know the constitutional remedy picture (whether given or not) then we can guess that the acute will often be its opposite (or complimentary), e.g: Calc-carb constitutionally may need Belladonna acutely, Nat-Mur may need Bryonia, Sulphur may need Arsenicum etc.

or

When the indicated remedy fails we can try related and complementary remedies

or

When the symptom picture fades or becomes difficult to recognise we can use intercurrants e.g. Sulph

or

When no remedy seems to work then we can use the appropriate nosode, and if still neceassary repeat the indicated remedy afterwards

or

When symptom matching fails we can try tautopathy / isopathy

or

When we get stumped we can address perceived dyscrasia and blocks to cure

or

When we are concerned about aggravation from high potencies but need an immediate response we can use descending potency

Thus there is a lot that can still be tried if the first remedies based on symptom homeopathicity fail