Methadone InjectionIf You Are Sick, It May Help To Take This Medicine With Food. Ask Your Doctor Or Pharmacist About Other Ways To Reduce Nausea (Such As Sleeping 1-2 Hours And Moving Your Head As Little As Possible). Nausea, Vomiting, Constipation, Dizziness, Dizziness, Dry Mouth, Drowsiness, Or Sweating. Some Side Effects May Decrease After Using This Medicine For A While. If Any Of These Side Effects Occur Or Worsen, Tell Your Doctor Or Pharmacist Promptly.Methadone Tablet Side EffectsTo Prevent Constipation, Eat A Fiber-rich Diet, Drink Plenty Of Water And Exercise. You May Need To Take A Laxative. Ask Your Pharmacist Which Type Of Laxative Is Right For You. To Reduce The Risk Of Dizziness And Lightheadedness,