4 yrs of propecia

[TheDude]

ok so i"ve been on propecia with minoxidil for 4 yrs and have started to notice that its loosing its effectiveness..

I know a lot of guys have felt and seen the same waning of the drug and have advocated increasing the dosage.

My question is if i change from the 1 mg propecia to proscar, taking half a tab of the proscar will this affect my hair loss negatively?
Is the half a tab of proscar the increased dosage that i shld be taking or sld i be taking a less percentage of the tab (keeping in mind that 1 full tab is 5 mg)
Finally is the increased mg of the drug going to have any increased side affects on me?

Anyone who has gone through a similar process and knows answers to any of these questions, i beseech thee to lend me a helping hand.. but seriously any help would be much appreciated