DRAG: Unlimited Turbo.
DRUB: Invulnerability.
DRUG: Screen wobble.
DREAD: Unlimited ammo.
DRINK: Rocket fuel.

You can use these codes at The Shop screen:

DRAW: $1,000 added to your account.
DROOL: $500,000 added to your account.
DRIVE: 10 points added to your score.