Do not take Doxazosin Winthrop 4 mg prolonged release tablets and associated names [See Annex I] • if you have ever suffered an allergic reaction (e. g. itching, reddening of the skin or difficulty breathing) to the active ingredient, doxazosin, or any of the other ingredients of {Invented name} • 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 are breast feeding.