You can quit the medicine if you are planning a family or if you feel problem in erection. Else, there is no need to quit

Is it causing any problem?...You are suffering from hormonal changes causing Androgenetic alopecia causing hair fall. It's completely stoppable even regrowth of hair is possible with certain medications without any side effects. Treatment depends on the grade of hair loss. So, it's a must for diagnosing which grade, you are in for an effective treatment. Please  send photos of your head, by direct online consultation for accurate diagnosis and proper treatment.

Hello It's better to talk to your consulting Trichologist/ Dermatologist If you have achieved your desired results, you can switched to just topical treatment