Do not take this medicine with any of the following medications:

-certain antipsychotics like chlorpromazine, haloperidol, pimozide, risperidone, and thioridazine
-certain medicines for irregular heart beat like dofetilide, encainide, flecainide, mexiletine, propafenone, and quinidine
-cisapride
-dolasetron
-dronedarone
-MAOIs like Carbex, Eldepryl, Marplan, Nardil, and Parnate
-mefloquine
-quinine

This medicine may also interact with the following medications:

-alcohol
-aprepitant
-certain antivirals for HIV or hepatitis
-certain medicines for depression like amitriptyline, citalopram, desipramine, escitalopram, fluoxetine, fluvoxamine, nefazodone, paroxetine, and sertraline
-certain medicines for fungal infections like fluconazole, itraconazole, and ketoconazole
-certain antibiotics like clarithromycin, erythromycin, and telithromycin
-codeine
-digoxin
-diltiazem
-grapefruit juice
-hydrocodone
-memantine
-other medicines that prolong the QT interval (an abnormal heart rhythm)
-verapamil

They need to know if you have any of these conditions:

-dementia
-heart disease
-history of drug abuse or alcohol abuse problem
-history of low blood counts caused by a medicine
-history of irregular heartbeat
-kidney disease
-liver disease
-low levels of magnesium or potassium in the blood
-myasthenia gravis
-an unusual or allergic reaction to dextromethorphan, quinidine, other medicines, foods, dyes, or preservatives
-pregnant or trying to get pregnant
-breast-feeding

Tell your doctor or healthcare professional if your symptoms do not start to get better or if they get worse. Visit your doctor or health care professional for regular checks on your progress.

You may get dizzy. Contact your doctor right away if you feel faint or have fainting spells while taking this medicine. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Avoid alcoholic drinks; they can make you more dizzy.

Keep out of the reach of children.

This medicine may cause accidental overdose and death if it taken by other adults, children, or pets. Mix any unused medicine with a substance like cat litter or coffee grounds. Then throw the medicine away in a sealed container like a sealed bag or a coffee can with a lid. Do not use the medicine after the expiration date.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F).