Well, if you notice male pattern baldness progressing on a single agent you look around and add another. There are multiple treatments which have fair evidence that they affect hair diameter and count. After the "big 3" fail you it is just a question of how much it is worth to you in money and convenience to continue to fight male pattern baldness. You might... (in addition to finasteride/minoxidil/nizoral)...
1) switch to dutasteride, one dollar a pill generic, with the risks that implies
2) addition of tricomin spray (copper peptide) daily
3) addition of topical spironolactone/fluradil or 5-FU for topical androgen blockade
4) try nano shampoo or doctor proctor's products
5) hair transplant
6) try retin-a topical
7) shave your head, quit the meds and buy a new car with the money you save