What other drugs affect codeine/guaifenesin/phenylephrine?
Before taking this medication, tell your doctor if you regularly use other medicines that make you sleepy (such as allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, or anxiety). They can add to sleepiness caused by codeine or guaifenesin. Also tell your doctor if you are using any of the following drugs: medicines to treat high blood pressure indomethacin (Indocin) mecamylamine (Inversine) methyldopa (Aldomet) reserpine a beta-blocker such as atenolol (Tenormin), carteolol (Cartrol), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal), sotalol (Betapace), timolol, and others; or an antidepressant such as amitriptyline (Elavil), clomipramine (Anafranil), imipramine (Janimine, Tofranil), and others This list is not complete and there may be other drugs that can interact with codeine, guaifenesin, and phenylephrine. Tell your doctor about all the prescription and over-the-counter medications you use. This