Common Name: Picrate of Iron   Causes & Symptoms for Dr. Reckeweg Ferrum Picricum Ferrum Picricum has marked action on bladder irritation. There is pain along entire urethra. Frequent urination at night, with a sensation of fullness and pressure in the rectum. There is smarting pain at the neck of the bladder and penis.  Ferrum Picricum also helps in retention of urine, prostate diseases and albuminuria.