Tanya Lewis: Hi, this is Your Health, Quickly, a Scientific American podcast series!

Josh Fischman: We bring you the latest vital health news: Discoveries that affect your body and your mind.  

Lewis: And we break down the medical research to help you stay healthy. I’m Tanya Lewis.

Fischman: I’m Josh Fischman.

Lewis: We’re Scientific American’s senior health editors. 

Fischman: Today we’re talking about decongestants. Scientists who advise the FDA recently concluded that phenylephrine, a common decongestant in cold medicines, doesn’t work. We’ll talk about what actually does.

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Lewis: I don’t know about you, Josh, but I have bad allergies and my sinuses are blocked pretty often. I’ve tried all sorts of things to help, from nasal sprays and decongestants to to antihistamines to hot showers. Some of these things help; some of them don’t.

Fischman: What helps you the most of all those things, Tanya?

Lewis: I find that the steroid nasal sprays work pretty well, but I don’t like to use them all the time.

Fischman: How come?

Lewis: Um, I just find that sometimes I develop a tolerance to it, so it stops having the same effect. Sometimes hot showers do help temporarily, but usually the congestion comes back.

Fischman: Yeah, and there’s only so long you can stand under a hot shower, right? 

Lewis: Right.

Fischman: I’ve tried those saline sprays up my nose. They kind of flush things out, and I feel more comfortable. But I have to use them for a bunch of days before I feel any difference.

Lewis: Yeah, those saline ones are pretty good. 

Fischman: Overall, I tend to go for decongestant tablets, which are supposed to reduce swelling inside my nose, opening up my airways.

Lewis: You’re not alone in preferring tablets. One of the most popular decongestant ingredients is phenylephrine. It’s found in drugs like Sudafed PE, Benadryl Allergy D Plus Sinus, and Vicks Dayquil Cold and Flu Relief.

But earlier this month, in a rare move, an FDA advisory panel declared that oral phenylephrine is completely useless at clearing up congestion.

Fischman: That really surprised me. I’ve been buying cold and flu medicines for years. And I always look to see if a decongestant like phenylephrine is in the capsule.

Lewis: I’d heard for a while that it wasn’t that effective, but it’s in a lot of cold medicines. In fact, it became popular because the standard over-the-counter decongestant, pseudoephedrine—the active ingredient in regular Sudafed—got locked up behind pharmacy counters.  That’s because it can be used as an ingredient in making methamphetamine.

Fischman:  I remember that. In the mid-2000s, all these cold medicines were suddenly put behind plexiglass windows with padlocks on them. I had to ask a pharmacist if I wanted some, and there was a limit to how much I could buy.

Lewis: Exactly. So more products started using phenylephrine. 

Fischman: Basically they were using it as a substitute?

Lewis: Yep. Phenylephrine was actually approved in the 1970s, so it had been around a while. But even back then, the FDA said it wasn’t very effective as a decongestant.

Jennifer Le: There was a cough and cold panel in 1972 in which the panel specifically noted that the data were not strongly indicative of efficacy. So this goes back quite a number of years.

Lewis: That’s Jennifer Le, a professor at the pharmacy school at the University of California, San Diego. She was on the recent FDA advisory panel earlier this month that made the decision that phenylephrine wasn’t effective.

Back in the 1970s, the FDA was more concerned with safety than effectiveness.

Le: So first and foremost, at the dose that's currently approved, 10 milligram for nasal congestion, it does not appear to provide any safety concerns, except in a very small population who has high blood pressure.

Lewis: Then, in 2007, an FDA advisory panel reviewed the data.

Le: And in reviewing the data they thought that efficacy was maybe suggestive at higher doses, and so the recommendation at that time was to obtain more clinical data. And the committee who reviewed it withdrew approval for those less than 12 years of age.

Lewis: Fast-forward to today, when another FDA panel—the one Le was on—reviewed the drug’s effectiveness again. They looked at more recent data on both how the drug is metabolized and how well it works in people.

Le: And the pharmacologic data side indicated that when you take oral phenylephrine, most of it is metabolized to inactive forms, so very little of the active drug—in fact, one percent, based on FDA data—actually gets into the blood.

Fischman: So most of the drug isn’t even making it to the nose, in other words.

Lewis: Exactly. In addition to that, three trials of oral phenylephrine showed it was no better than a placebo at relieving congestion.

So the committee voted unanimously that oral phenylephrine is basically useless.

Fischman: The FDA panel only reviewed forms of the drug that come in capsules, tablets and syrups, though. So what about things like nasal sprays?

Lewis: They didn’t review phenylephrine nasal sprays. Those might still be effective since they are going right into your nose. But the oral pills won’t do much.

Fischman: But I’ve been taking these cold medications with phenylephrine for years and they do make me feel better. I think. Is that just a placebo effect?

Lewis: Not necessarily. Those meds usually are a combo of several ingredients such as acetaminophen, which helps reduce pain and fever, and antihistamines, which help in the first few days. So the combo may still make you feel better.

Fischman: Overall, though, if oral phenylephrine doesn’t work, what should people use instead of it?

Lewis: I asked Le the same question. She basically said that for short-term congestion with a cold, you should just wait it out.

Le: The nasal congestion that occurs with the common cold is self-limiting. And so if it's possible, and if it's tolerable—I have a very high tolerance rate when it comes to symptoms—let it resolve. Let the symptom resolve. You know, there's nasal saline products that can maybe help with congestion a little bit. A warm, hot bath, a humidifier can help with some of that too. 

Fischman: But Tanya, you said you tried a lot of those things, and often they don’t work. 

Lewis: Yeah, I find that most of them only offer temporary relief.

Fischman: So are you just supposed to walk around with your nose blocked or running for a week and a headache pounding—maybe a box of tissues tucked under your chin? 

Lewis: I know, right? It really doesn’t seem great. There are other decongestants, like pseudoephedrine, which you can get by asking a pharmacist, like we mentioned earlier. And that works pretty well. You can also use nasal sprays like Afrin, but be careful—if you use those longer than three days, they can cause your symptoms to rebound.

Fischman: What about other sprays, like Flonase or Nasacort?

Lewis: Those steroid nasal sprays work pretty well. But ask a doctor if you’re congested for longer than a few days, because you might have chronic inflammation due to allergies.

Fischman: And allergies are a different story, right? 

Lewis: Right. For that kind of congestion, you should consult an allergy specialist. The standard therapy involves some combination of oral and nasal antihistamines and nasal steroids like Flonase. In some cases, you can get allergy shots or even surgery.

Fischman: Okay, but for colds, clearly it’s time to restock my medicine chest. Those saline sprays do help me, so maybe some more of those. And if I have a rougher case, it looks like I’m going to ask the drugstore to take out their keys, and open up their pseudoephedrine stash. 

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Fischman: Your Health, Quickly is produced by Tulika Bose, Jeff DelViscio, Kelso Harper, Carin Leong, and by us. It’s edited by Elah Feder and Alexa Lim. Our music is composed by Dominic Smith.

Lewis: Our show is a part of Scientific American’s podcast, Science, Quickly. Subscribe wherever you get your podcasts. If you like the show, give us a rating or review!

And if you have ideas for topics we should cover, send us an email at Yourhealthquickly@sciam.com. That’s your health quickly at S-C-I-A-M dot com.

I’m Tanya Lewis.

Fischman: I’m Josh Fischman.

Lewis: See you next time.