The Washington Post recently published an article showing how an antibacterial chemical in soap is now on FDA’s hit list. The FDA is reportedly going to require that manufacturers prove antibacterial soaps are safe and more effective than regular soap and water.
The problem that I had with the FDA’s request for more research to prove the safety and efficacy of triclosan, the ingredient under scrutiny, was that a PubMed search shows 1915 articles using the keyword “triclosan”. What more research does the CDC want?
According to an FDA Consumer Update triclosan has “altered hormone regulation” in animals and other studies [not cited in the FDA update] have “raised the possibility” that the chemical may make bacteria resistant to antibiotics.
First of all, I’m not going to take sides on whether using antimicrobial soap is always a good or bad thing. Personally, I think that using it under circumstances where there is greater risk for transmission of disease is appropriate. Cutting up raw chicken? Use antibacterial soap afterwards. Changing a diaper full of foul-smelling diarrhea? Ditto. Hospital patient contact? Maybe. ICU patients? Probably. Post op patients? Yes. To me, it ends up being a judgment call. If there’s no harm in using it, what’s the problem?
So let’s look at some data.
Research Already Shows Triclosan is Safe and Effective
Below are just a smattering of the studies I found demonstrating the safety and effectiveness of triclosan. Remember that triclosan has been approved for use since 1972.
- This 1989 study showed that triclosan was safe for use in mouthwash and toothpaste.
- This August 1999 study showed that both 1% triclosan and 4% chlorhexidine were effective at reducing pathogens on hands in a surgical unit, but that triclosan also killed MRSA while chlorhexidine did not.
- This April 2000 review showed that triclosan “is a widely accepted antimicrobial ingredient because of its safety and antimicrobial efficacy” and “has demonstrated immediate, persistent, broad-spectrum antimicrobial effectiveness and utility in clinical health care settings.”
- 2% triclosan was shown effective in reducing MRSA skin colonization (where the organism is present on the skin but is not causing an “infection”).
- 1% triclosan was used in one Australian study to cause a “highly significant reduction” in the number of MRSA carriers and infections in a Cardiothoracic Surgical Unit.
- Adding .3% (or 0.3% if you’re following some inane Joint Commission rules for medical charting) triclosan to handwashing and bathing soaps caused an “immediate termination” in the acute phase of a MRSA outbreak in a nursery and maintained the MRSA-free status for more than 3 years.
- 1.5% triclosan soap decreased the spread of shigella as compared to plain soap and water when used after changing diapers of babies with diarrhea.
- And although not a study involving hand soap, this 2013 study showed that when sutures coated with triclosan were used during colorectal surgeries, the incidence of wound infections was cut in half.
Claims That Triclosan “Alters Hormone Regulation” Are Speculative
Triclosan is somewhat structurally similar to thyroid hormones. The theory is that using triclosan would cause the body to shut down its thyroid hormone production, causing “altered hormone regulation.”
If you’re a North American bullfrog, triclosan may be a problem. This study showed that triclosan altered thryroid hormone receptor expression in premetamorphic tadpoles.
Off of the lilypad, when people used .3% triclosan toothpaste for 4 years, researchers did find a significant decrease in the free thyroxine levels at the end of five years … in the control subjects who weren’t using the triclosan. In other words, using triclosan was associated with protected thyroxine levels and hormone regulation, not altered hormone regulation.
Claims That Triclosan May Cause Antibiotic Resistance Don’t Hold Water
A couple of studies showed that there wasn’t any relationship between triclosan use and antibiotic resistance.
- This 2004 article showed that there was no association between the resistance levels of bacteria to triclosan and the subsequent susceptibility of the bacteria to other antibiotics. However, the authors of the article noted a nonsignificant “trend” toward greater resistance – which statistically means nothing, but is a study author’s way of using bias to bolster one’s assertions. If it isn’t statistically significant, why mention it?
- This 2012 study looked at several other antibacterials in addition to triclosan, but still showed that there was no difference in the incidence of drug resistant bacteria between homes that did and did not use household antibacterial agents.
Additional Triclosan Articles
Then there was this 2007 article noting that soaps using triclosan concentrations between .1% and .45% were not any more effective than plain soap at preventing infectious illnesses or at reducing bacterial levels on the hands. The article concluded that
The lack of an additional health benefit associated with the use of triclosan-containing consumer soaps over regular soap, coupled with laboratory data demonstrating a potential risk of selecting for drug resistance, warrants further evaluation by governmental regulators regarding antibacterial product claims and advertising
Nary a year later, there was this letter to the editor of the Journal of Antimicrobial Chemotherapy showing how when another disinfectant called benzalkonium chloride was used along with low-concentration triclosan, that there was a higher resistance to both benzalkonium and triclosan. However, the data wasn’t clear and it lumped together all the different bacteria studied instead of reporting on each of the antimicrobials and bacteria separately.
Both of the above articles and the 2004 article showing a “nonsignificant trend” toward antibiotic resistance had two common authors, Stuart Levy and Elaine Larson.
Stuart Levy and his pharmaceutical company Paratek Pharmaceuticals recently published a couple of articles on a new tetracycline-based antibiotic called Omadacycline. Now this is an oral antibiotic and not a topical disinfectant, so there’s no overt conflict of interest.
But is there a “nonsignificant trend” toward a conflict?
So I began to wonder …
Why is the FDA just now giving us a “Consumer Update” on an issue raised in 2007?
What studies does the FDA have to bolster its assertions and why isn’t the FDA releasing those studies?
Why are two authors publishing multiple articles whose aim appears to be removing topical antimicrobials from hand sanitizers when many studies show that there is a benefit to having those antimicrobials present?
Do you use antibacterial soap?
What do you think about the FDA’s investigation?
Here are some additional articles about the FDA’s issues with triclosan
ABC News: Popular Antibacterial Soap Ingredient Draws FDA Scrutiny
Fox News: FDA to decide if common chemical in antibacterial soap is safe
NY Times: Antibacterial Chemical Raises Safety Issues