Yes, DRACHMS is a Scrabble word!

Letter values in Scrabble US: D 2, R 1, A 1, C 3, H 4, M 3, S 1.

Is it a valid word?

DRACHMS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a unit of apothecary weight equal to an eighth of an ounce or to 60 grains
a British imperial capacity measure (liquid or dry) equal to 60 minims or 3.5516 cubic centimeters
a unit of capacity or volume in the apothecary system equal to one eighth of a fluid ounce

Also: fluid dram, fluid drachm.