Decongestants are medications that help open the nasal passages of people who experience congestion due to common coldscommon colds, the flu or allergies.These drugs work by constricting the small blood vessels of the nose, which forces blood out of the vessels and opens the nasal passage, allowing people to breathe more easily. The two main types of decongestants used to treat colds are pseudoephedrine and phenylephrine.

Decongestants are available as stand-alone medications and in combination with other medications. Some of the decongestants offered in combination with other medications are used to treat colds and the flu. These include:

• Decongestant/antihistamine combinations
• Decongestant/analgesic (pain relief) combinations
• Decongestant/antihistamine/analgesic combinations
• Decongestant/antihistamine/anticholinergic (antispasmodic) combinations

Patients should not take decongestants (even over-the-counter versions) unless they have consulted a physician. Decongestants can cause dangerous interactions with certain medications and potentially complicate certain health conditions. Several types of side effects also are common with decongestant use, although most are not a cause for concern. Symptoms of overdose can be similar to the medication’s side effects, but are usually more severe.

Decongestants may be dangerous when used by certain populations, including pregnant and breastfeeding women, children and the elderly. For this reason, it is particularly important that people in these groups consult a physician before using any type of decongestant.