Hi, Thanks for posting in HCM. I understand your concern. Terazosin belongs to a group of drugs called alpha-adrenergic blockers . It relaxes the muscles in the prostate and neck of the bladder, thus, making it easier to urinate. Hence, it is used to improve urination in men with benign prostatic hyperplasia (enlarged prostate). Dizziness, lightheadedness, tiredness, nausea, drowsiness, blurred vision, headache or stuffy nose may occur as side effects on intake of this medication. If any of these symptoms persist or worsen, you need to seek medical attention promptly. Soreness what you are noticing on your penis is not due to the side effect caused due to this medication. It could be due to inflammation of the skin in the region. Kindly do the following to overcome the same. 1. Clean the area with mild antiseptic solution like Savlon twice daily. 2. Use anti-bacterial medicated soaps to take bath regularly. 3. After drying, apply Neomycin with Hydrocortisone cream over the lesions. 4. Wear loose fitting undergarments to prevent friction and providing proper ventilation. 5. Abstain from sexual activities till the lesions heal completely. Main good personal hygiene. Gradually your symptoms should subside and be back to normal. Hope the information provided would be helpful. All the best.