What are the possible side effects of Guiavent ER (Guaifenesin Phenylpropanolamine)?
No serious side effects from guaifenesin and phenylpropanolamine are expected. Seek emergency medical attention if you experience an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives). Other, less serious side effects may be more likely to occur. Continue to take guaifenesin and phenylpropanolamine and talk to your doctor if you experience dizziness or headache nervousness, restlessness, or insomnia nausea or stomach upset; or difficulty urinating Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.
