Similar Question To The One Below. I Was Given Alprim

Similar question to the one below. I was given alprim yesterday for bacteria infection in the bladder following a hysterectomy last week. I took the first tablet at 10 a.m. yesterday and the pharmacist suggested I wait until tonight to take the 2nd one, then continue at night. It seems an extra 8 hours on top of the 24 hours that I will have to wait to take the 2nd one. Will that gap mean that the antibiotic won't work as quickly.