What Treatment Is Suggested For Blemishes Due To Pimples?

Hi Doctor, Good After Noon, I am visiting the doctor(Dermatologist) from fast 1 year for the treatment of black spots(remained after pimples) and also kind of pigmentation(Changing the face skin color to black if i stop the cream).Doctor is suggesting me to Use different creams(keeps on Changing the creams) like Lumifair (advanced Day cream,night cream)cream,Elovera in the nights for whole face and kojitin on the black spots.it is giving me the results(i mean face looks good with out pigmentation). But the Doctor always asks me to visit him for every one month and he Changes the creams(lumifair,elovera(made by glenmark pharmaceuticals),nevlon moisturizing)regularly.and always he writes vitamins tablets(daily two) along with these creams. I cannot Afford the money every month. I finally observed that vitamin tablets are not playing any role but the creams are playing the role. So, i want to use the cream Elovera imf (for full face) and on the same face after 15 min kojitin on dark spots only in the nights--- Can i Use these for long term. Are there any side effects of these products ?.If No I will use these products in long term worried if any thing happens in the long term if i use these products. Please suggests me on this