What Could Cause Burning Sensation During Masturbation While Getting Treated For Trichomoniasis Vaginalis?

Hi, I am 26 years old male and I have trichomoniasis vaginalis and my doctor prescribed me 2g of metrodinazole . I took metrodinazole but very next day i did mastrubation 3 times. And there is lots of burning in my penis. .I want to ask is there any negative affect can occur on the tricho treatment? Should i take 2g metrodinazole again ?