Alka seltzer plus and high blood pressure

Opinion > Skeptical Cardiologist

— The Skeptical Cardiologist has some seasonally-appropriate cautions

by January 22, 2020

Little has changed in the $8 billion world of useless and confusing over-the-counter (OTC) cold, flu, and sinus medications since the Skeptical Cardiologist first tackled "What Cold Medications Are Safe For My Heart" in 2015.

I still advise avoiding combination OTC cold meds and utilizing specific medications for specific symptoms.

The original post covers most of the usual suspects in this mostly useless arena. I updated it in 2016 with comments on a few additional OTC components. That post on Alka-Seltzer, phenylephrine, and doxylamine is included below.

Alka-Seltzer Plops Into the OTC Cold Market

I had always viewed Alka-Seltzer as an effervescent tablet for acid reflux, but the brand (now owned by Bayer) has moved aggressively into the bewildering morass of OTC cold meds. Indeed, when Alka-Seltzer began in 1931, it was a combination of aspirin and sodium bicarbonate (baking soda) marketed for upset stomachs. Popular commercials from the 1960s featured the catchy jingle (still stuck in my head) "Plop, plop, fizz, fizz. Oh what a relief it is" often sung by Speedy, an odd anthropomorphic creature with an Alka-Seltzer thorax and cap. (The jingle was written by Tom Dawes of The Cyrkle ["Red Rubber Ball"], not by the father of Julianna Margulies.)

Recently, I received a request from an out-of-town guest who was suffering from a cough and upper respiratory infection to purchase Alka-Seltzer Plus in the form of a tablet that dissolves in hot water.

At his request, Alka-Seltzer Plus Day Multi-Symptom Cold and Flu was purchased at the local Walgreens.

The ingredients are typical for many of the Alka-Seltzer products:

• Dextromethorphan (promoted for cough but ineffective and with considerable side effects, see my initial post)
• Acetaminophen (Tylenol, for pain and fever)
• Phenylephrine (decongestant)

Phenylephrine: Ineffective Substitute for Pseudoephedrine

I didn't cover phenylephrine previously. It has taken the place of pseudoephedrine in on-the-shelf OTC cold medications.

Like pseudoephedrine, phenylephrine is a sympathomimetic drug, meaning it stimulates receptors of the sympathetic nervous system. Unlike pseudoephedrine, phenylephrine is useless as a decongestant when taken in the dosages available over the counter.

A study published in 2015 confirmed what previous studies had suggested: Phenylephrine in dosages of 10 to 40 mg daily was no more effective than placebo in reducing symptoms of nasal congestion.

An accompanying editorial called on manufacturers to remove this useless drug from their products.

Alas, all of the Alka-Seltzer preparations that claim to treat congestion utilize phenylephrine as the decongestant.

The transition to useless phenylephrine took place when pseudoephedrine was taken off the shelves and put behind the counter to reduce its usage in making methamphetamine.

Therefore, Alka-Seltzer Plus Cold and Flu contains two useless ingredients plus acetaminophen (Tylenol).

You can buy a large bottle of cheap generic acetaminophen and take exactly the right dose you need for relieving fever or body aches without paying for two useless accompanying drugs that have the potential for giving you unwanted side effects.

Sleep Aids in OTC Cold Meds

I covered the most common drug found in OTC cold meds promoted for nighttime use, diphenhydramine (Benadryl), in my previous post.

Nighttime Alka-Seltzer products contain a similar sedating antihistamine called doxylamine succinate.

Doxylamine is the active ingredient in the brand-name sleep aid Unisom and the "ZzzQuil" products from the NyQuil brand that are promoted for inducing sleep. It is available in cheap, generic form.

According to DrugBank, "It is also the most powerful over-the-counter sedative available in the U.S., and more sedating than many prescription hypnotics. In a study, it was found to be superior to even the barbiturate, phenobarbital for use as a sedative."

Note that the effective dosage recommended in separate sleep aids is 25 mg, not the 12.5 mg found in Alka-Seltzer OTC cold meds. Thus, if you want an effective dosage of doxylamine to help you sleep, you must double the recommended dosage of Alka-seltzer's nighttime product, which then gives you too much acetaminophen and dextromethorphan.

Doubling these drugs raises the potential for side effects. Common dextromethorphan side effects include nausea/vomiting, dizziness, diarrhea, and nervousness. Too much acetaminophen can damage the liver.

In addition, both dextromethorphan and acetaminophen interact with multiple other medications. Dextromethorphan is known to interact with many medications.

Acetaminophen can interfere with warfarin and increase the risk of dangerous bleeding.

My advice for 2020 is unchanged from 2015. As I summarized previously:

"I think you are much better off avoiding these brand name mixtures of different active ingredients.

Instead, you should take what you need for a specific symptom in the appropriate dosage and time interval.

Thus, if you have pain, take the minimal dose of Tylenol that relieves it and repeat when it comes back.

If you have a cough, recognize that the OTC ingredients are no better than placebo and are being abused as recreational drugs. Most coughs go away shortly; but if one is particularly troublesome and persistent, get a cough suppressing drug from your physician.

If you have a really runny nose with a lot of sneezing, it is probably OK to take pseudoephedrine even if you are a heart patient or have high blood pressure. Take it as I described above. Start with 30 mg of the little red pseudoephedrine pills. Wait an hour to see how you feel. Take a second if it has not been effective. Repeat at 4 to 6 hour intervals as needed. Take your blood pressure at least once after starting it.

Don't buy the multi-symptom multiple ingredient combinations, which are simply a marketing tool to get you to spend more money on something from which you won't benefit."

Consumer Reports seems to agree with me in a 2017 post on this topic (which doesn't credit me).

Anthony Pearson, MD, is a private practice noninvasive cardiologist and medical director of echocardiography at St. Luke's Hospital in St. Louis. He blogs on nutrition, cardiac testing, quackery, and other things worthy of skepticism at The Skeptical Cardiologist, where a version of this post first appeared.

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