Terazosin hydrochloride is white, crystalline substance, freely soluble in water and isotonic saline and has molecular weight of 459. Patients should know that this reaction to HYTRIN is extremely rare, but that if it is not brought to immediate medical attention, it can lead to permanent erectile dysfunction impotence. Nursing Mothers It is not known whether terazosin is excreted in breast milk. Call your doctor at once if you have any of these serious side effects: fast or pounding hytrin sin receta feeling light-headed, swelling in your hands, ankles, or or penis erection that is painful or lasts hours or longer. This lesion has also been seen with Minipress another marketed selective-alpha-1 blocking agent.