Decoding OTC Cough & Cold Medication Ingredients

Sure, it's only August but subtle signs of fall are here. The air's a bit crisper in the morning. The evenings are getting shorter. And, a sprinkling of crispy leaves has made its way to my lawn. What does this mean for nurse practitioners? Cough, cold and flu season is coming! 

This time of year, I find my patient load is peppered with complaints of flu-like illnesses. One thing my patients want to know is which over-the-counter medications I recommend to cure what ails 'em. If you're a nurse practitioner or NP student who isn't quite sure what exactly those ingredients in combination cough and cold medications actually do, here's a quick brush-up. 

Antipyretics 

Generic Names: acetaminophen, ibuprofen 

As nurse practitioners we're most familiar with these fever-fighting drugs. Acetaminophen (Tylenol) and ibuprofen are the most common fever reducers you'll find in combination cough/cold products. We covered the efficacy of antipyretics in a post last week. Check out the post for a more in-depth discussion on efficacy. 

Don't forget to warn your patients about the presence of acetaminophen and ibuprofen or other NSAIDs in combination cough/cold products. It's important to make sure they're aware so as not to inadvertently overdose. 

 

Decongestants 

Generic Names: pseudoephedrine, phenylephrine 

Pseudoephedrine and phenylephrine are the primary oral decongestants on the market. How do you tell the difference between them? You can make a quick determination as decongestants containing phenylephrine have the term 'PE' in the name. For example, Sudafed's active ingredient is pseudoephedrine where as Sudafed PE's active ingredient is phenylephrine. Decongestants work by taking vasoconstrictive action in the nasal mucosa.

A few pointers to know when it comes to decongestants: 

1. Pseudoephedrine has potential for misuse so is kept behind pharmacy counters and may require a prescription in some states.

2. Pseudoephedrine is more effective than phenylephrine.

3. Decongestants notoriously have an effect on blood pressure - but not much. A 2005 study shows that pseudoephedrine increases systolic blood pressure by 0.99mmHg and heart rate by 2.83 beats per minute. Study results showed no effect on diastolic BP. The effect was deemed small but significant. Data is lacking about phenylephrine's effect on blood pressure. 

 

Cough Suppressants

Generic Names: Dextromethorphan

While many OTC combination products market themselves for cough (ex. antihistamines), dextromethorphan is the true OTC cough-suppressing agent. Dextromethorphan's chemical structure is similar to that of codeine, however it lacks codeine's analgesic and addictive properties when used at recommended doses.  

Nurse practitioners should be aware of the potential for dextromethorphan abuse. In a fad called 'robo-tripping' (based on the brand of popular cough medication Robitussin), teens get a high from ingesting large amounts of dextromethorphan. Users report hallucinations and euphoria although ingesting such amounts of cough medications can also lead to nausea, vomiting and tachycardia.

The jury's still out on dextromethorphan efficacy. Some studies show it works, others do not. One analysis of six trials showed that dextromethorphan suppressed cough by about 12 to 17 percent. 

 

Expectorants

Generic Names: Guaifenesin

Expectorants help loosen phlegm and bronchial secretions essentially making it easier to cough them up and clear the airway. Guaifenesin is the sole OTC expectorant on the market so you'll see it as a common ingredient sold alone or in combination with other cough and cold medication ingredients. 

A few pointers to note about the drug: 

1. Adequate hydration is important during use.

2. The most effective way to administer guaifenesin oral granules is to place under the tongue and swallow without chewing - guaifenesin granules have a foul taste if chewed!

3. Guaifenesin is pretty safe (the primary side effect is mild GI irritation), but it also hasn't been shown to be very effective.

 

Antihistamines

Generic Names: Diphenhydramine, chlorpheneramine, bropheniramine, cetirizine, loratadine

Antihistamines are multi-purpose in OTC cough/cold preparations. Some manufacturers market them as cough suppressants. Others market them for purposes of decreasing rhinorrhea and ocular irritation. First generation antihistamines (diphenhydramine, chlorpheneramine, bropheniramine) can cause drowsiness. Second generation antihistamines (cetirizine, loratadine) come with minimal sedative effects.

In kids, studies show that antihistamines are not effective for treatment of common cold symptoms and that the risk of side effects does not outweigh potential benefits. In adults, antihistamines may offer slight relief of common cold symptoms, particularly when used in combination with a decongestant.

 

You Might Also Like: Should You Recommend OTC Cough and Cold Meds to Kids?

 

Resources: 

Woo, Teri. Pharmacology of Cough and Cold Medications, Journal of Pediatric Healthcare. March-April 2008, Volume 22, Issue 2, Pages 73-79. 

Wicker, Ann; Labruzzo, Brice. Recommendations for the Use of Cough and Cold Medications in Children. US Pharmacist. 2009; 34(3): 33-36. 

Sexton, Daniel. The Common Cold in Adults: Treatment and Prevention. UpToDate. January 29, 2018.