Important Information for Your Healthcare ProviderTalk with your healthcare provider prior to taking dextromethorphan if you have:
- Lung problems, such as asthma, emphysema, or chronic bronchitis
- A cough that has lasted more than seven days
- A cough that is accompanied by excessive phlegm or mucus
- A cough that went away and came back
- A fever, rash, or persistent headache
- A tartrazine (FD&C Yellow No. 5) sensitivity
- A history of an allergic reaction to aspirin
- A history of abusing drugs or alcohol
- Any allergies, including to medications, foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- A smoker
- Pregnant or thinking of becoming pregnant (see Dextromethorphan and Pregnancy)
- Breastfeeding (see Dextromethorphan and Breastfeeding).
Make sure to tell your healthcare provider about all other medications you are taking, including prescription and nonprescription medicines, vitamins, and herbal supplements.
(Click Precautions and Warnings With Dextromethorphan to learn more, including information on who should not take the drug.)
How Does It Work?Dextromethorphan suppresses coughing through its actions in the "cough center" of the brainstem, the lower part of the brain that connects to the spinal cord. It increases the threshold for coughing, which helps to reduce the body's reflex to cough.
Dextromethorphan has other actions in the brain, which may help it work to treat pseudobulbar affect (a nervous system condition associated with uncontrolled episodes of crying or laughing). It blocks N-methyl-D-aspartate receptors (more commonly called NMDA receptors), which prevents the action of glutamate, an excitatory brain chemical. In addition, it binds to sigma receptors. Although the exact role of sigma receptors in the brain is unknown, they may play a role in certain neurological diseases.