Renaming things with resource packs in minecraft (specifically potions)?

I've been making a resource pack and renaming many of the items in vanilla Minecraft. To me, it seems that the variables to change potion names are not working. I tested this with 1.8.8 and the most recent snapshot. The names of other items that I have changed are working.

I am modifying the en_US.lang file.

Here are some variables that I changed but don't seem to do anything:

item.emptyPotion.name=Basic Pill
entity.ThrownPotion.name=Syringe
potion.prefix.grenade=Syringe
item.potion.name=Dose 
potion.moveSpeed.postfix=Dose of Swiftness 
potion.potency.0=Level 1
potion.effects.whenDrank=When taken: 
potion.empty=This capsule contains no drugs. 
item.emptyPotion.name=Basic Pill

For some reason, potion.potency.1=Level 2 works, whereas potion.potency.0=Level 1 doesn't.

I realize that some of these variables probably wouldn't affect item names in game. However, I have change all the variables in this file that contain the words I am trying to replace (i.e. 'splash potion,' 'potion,' and 'water bottle.') and the corresponding items in game remain unchanged.

I am hoping this isn't a glitch and there is something I am missing. Thanks in advance for your replies.

(And yes before anyone asks I am making a drug themed resource pack for a specific purpose)