Pill Imprint AO 58
This blue and white elliptical / oval pill with imprint AO 58 on it has been identified as: Guaifenesin/phenylpropanolamine 400 MG-75 MG.
This medicine is known as guaifenesin/phenylpropanolamine. It is available as a prescription and/or OTC medicine and is commonly used for Cold Symptoms, Cough and Nasal Congestion.