DRUG INTERACTIONS: Your healthcare professionals (e.g., doctor or pharmacist) may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop or change the dosage of any medicine before checking with them first.Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication.Before taking this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially: antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray), antispasmodics (e.g., atropine, belladonna alkaloids), beta blockers (e.g., metoprolol, atenolol), drugs for Parkinson's disease (e.g., anticholinergics such as benztropine, trihexyphenidyl), guanethidine, certain inhaled anesthetics (e.g., halothane), methyldopa, reserpine, scopolamine, tricyclic antidepressants (e.g., amitriptyline, desipramine).Guaifenesin is available in both prescription and nonprescription products. Check the labels on all your medications carefully to make sure you are not taking more than one guaifenesin-containing product.Tell your doctor or pharmacist if you also take drugs that cause drowsiness such as: certain antihistamines (e.g., diphenhydramine), anti-seizure drugs (e.g., carbamazepine), medicine for sleep or anxiety (e.g., alprazolam, diazepam, zolpidem), muscle relaxants, narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., chlorpromazine, risperidone, amitriptyline, trazodone).Check the labels on all your medicines (e.g., cough-and-cold products, diet aids) because they may contain ingredients that could affect your heart rate/blood pressure or cause drowsiness. Ask your pharmacist about the safe use of those products.This medication may interfere with certain urine laboratory tests (e.g., 5-HIAA levels, VMA levels), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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