Hi, My cat, deNiro, has been on Prozac 5mg daily since October 2016 and we have seen improvements in his behavior with our other cat and with spotting. I had our vet call the prescription into the local Walgreens and it came as 10 mg pills. I break the pills in half and put them into 'pill pockets.' For 85% of the time, they work. Every now and then he happens to bite directly into one and spits it out. However, overall, he loves the chicken flavored pill pockets and only gets them when it is dosing time. I usually start with one or two blanks, depending on his mood, then go for the real deal. I receive a prescription for about $30.00 for 30 pills so with splitting them it runs me about $15.00/ month not counting the treats. He only weighs 8 lbs, is 6, and 5mg / day is within the recommended dosing for him. I am not sure of your cat's age or weight but maybe going up to 5 mg from 4mg might work. Or, giving 5 mg every other day as an option also. If your vet recommends 4 mg x 7 days that's a weekly dose of 28 mg. 5 mg x 6 days = 30 mg is also an option; give one day off.