Prescription Math Question

In our latest question and answer, the pharmacist answers a prescription calculation question.


I was prescribed Tylenol 3 20 tablets on 12/16/17 I am suppose to take 2 tablets every 6 hours how long will this prescription last.

Asked by Wag On Dec 18, 2017

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Dec 20, 2017

If taken as prescribed, 2 tablets every six hours would equal 8 tablets per day. Therefore, 20 tablets would last slightly over 2 days.

About the Pharmacist

Dr. Brian Staiger Pharm.D

Dr. Brian Staiger is a licensed pharmacist in New York State and the founder of He graduated from the University At Buffalo with a Doctor of Pharmacy degree in 2010. He has been featured in numerous publications including the Huffington Post as well as a variety of health and pharmacy-related blogs. Please feel free to reach out to him directly if you have any inquiries or want to connect! He's answered thousands of medication and pharmacy-related questions and he's ready to answer yours! Office: 716-389-3076

Recent Questions