Drastic

a.

1.

(Med.) Acting rapidly and violently; efficacious; powerful; - opposed to bland; as, drastic purgatives.

Adj.

1.

drastic - forceful and extreme and rigorous; "drastic measures"

Draconian, acute, cutting, desperate, dire, excessive, exorbitant, extravagant, fierce, forceful, furious, great, harsh, immoderate, intemperate, intense, keen, outrageous, piercing, potent, powerful, puissant, radical, rigorous, sharp, splitting, strong, unconscionable, vehement, venomous, vigorous, virulent