Do not take Doxazosin Retard Arrow 4 mg prolonged release tablets and associated names • if you are allergic (hypersensitive) to doxazosin or any of the other ingredients of Doxazosin Retard Arrow 4 mg prolonged release tablets and associated names • if you know that you are sensitive to quinazolines (e. g. prazosin, terazosin) which is the chemical family of medicines to which doxazosin belongs • if you have any kind of congestion or blockage in your urinary tract, an infection of the urinary tract or have bladder stones • if you have a serious kidney disorder (anuria or progressive renal insufficiency) • if you suffer from a loss of bladder control (bladder overflow) • if you have or have ever had any form of obstruction of the digestive tract if you are breast-feeding.