Is there ANY alternative to minox? (Redensyl, Procapil, anything)

Hello. I used minoxidil for a couple of years, and then had to discontinue due to sides (heart palpitations, cardiologist suggested I stop). Then my hair rapidly deteriorated, and I decided to go for a transplant. The transplant doc advised I use minox again, for a span of 6-8 months for good growth and then stop. I followed this, and the growth seemed okayish. Now a year into my procedure, I've LOST everything. My doctor says I'd have to take the minox again. But I fear the sides.