UPDATE: Hey! My allergy reaction was due to environmental contact so basically I had "contact dermatitis". I was prescribed 2 medications below. I must say I feel and look better. Lets learn from my medication by calculating the day supply!

RX: Benadryl (diphenhydramine) 50mg capsules
Sig: Take one capsule by mouth every 6 hours
Quantity: 15 capsules
Classification: Anti-histamine
Treatment: Allergies, common cold, itching, hives, rashes, etc
NOTE: May cause drowsiness (which it did for me, I'm all dizzy)

24 / 6 hours = 4 times a day       15 / 4= 3.75 -----4 days supply


RX: Medrol Dosepak (methylprednisolone) 4mg tablets
Sig: Take by mouth as directed
Quantity: 1 pack
Classification: Steroids
Treatment: Allergic states, Rheumatic disorders, ophthalmic diseases, etc
NOTE: Take with food because it can be harsh in the stomach (which it's true I took this med the first day without food and my stomach was hurting, felt awful)
If you notice in the picture a tablet pattern is starting from 6 tablets to 1 tablet. In total this pack has 21 tablets. Here is how to take this med in order to calculate day supply.

1st day: Take 2 tabs before breakfast, 1 tab after lunch & supper, and 2 tabs at bedtime
2nd day: Take 1 tab before breakfast, 1 tab after lunch & supper, and 2 tabs at bedtime
3rd day: Take 1 tab before breakfast & 1 tab after lunch, after supper, & at bedtime
4th day: Take 1 tab before breakfast, after lunch, and at bedtime
5th day: Take 1 tab before breakfast and at bedtime
6th day: Take 1 tab before breakfast

Obviously day supply will be 6 days since the medication is specifically instructed to take for 6 days.