Can Saline Additives Be Harmful?

Saline - Additives, Preservatives, Antibacterial Agents, Antifungal Agents

• Intro: Problems Due To Additives
• Thimerosal
• Benzalkonium
• An Additive-Free And Better Saline Solution
• Problems with Hypertonic Saline
• Pediatric Use of Saline Nasal Sprays
• References

 

The Additives May Be The Problem

Saline nose drops are often prescribed for nasal and sinus conditions. These are recommended for dryness, crusting, and as an aid to normal nasal function. Saline sprays can also be used to treat nose bleeds.

The nose is supposed to moisten inhaled air, helping to maintain a moist environment for the cilia in the sinuses. These cilia are the body's first line of defense against infection. The moist, mucous environment also forms a pathway for the good white cells to reach the bad bacteria that may attempt to infect the body through inhalation.

Any dryness, itching, or crusting in the nose means that a moisturizer is needed for the nose to do it's job. Saline is the most common, safe, and simple such moisturizer. When I first heard patients complain that saline burned or made their nose worse, I was very puzzled. Then I figured out that the troubles might be the result of the additives. Here is a partial list of the additives found in saline nasal sprays:

To avoid additives, I had patients make saline themselves, using Kosher or Pickling salt - a simple, pure salt. This cleared up the burning problem, and made kids more likely to take to regular use of the spray.

Some patients did not respond, however, even to the saline made without preservatives. The explanation came only recently from Professor Wilbert M Boek of University Hospital, Utrecht. He found that certain solutions containing potassium chloride, calcium chloride, sodium bicarbonate, and salt were much better for restoring nasal/sinus cilia than those without these ingredients. My clinical experience has borne this out.

Thimerosal

There is yet more complexity to the business of additives. Thimerosal (merthiolate) is a preservative that contains ethyl mercury. It has been used in small amounts to reduce the chance of bacterial growth since the 1930s. On July 9, 1999, however, the US Public Health Service (USPHS) and the American Academy of Pediatrics (AAP) officially called for the elimination of such preservatives from some drugs, suggesting serious questions about the safety of such additives.

Benzalkonium

The preservative Benzalkonium Sodium causes problems with nasal sprays. Around 1985, it was noted that the number and severity of cases of rhinitis medicamentosum was increasing with increased use of benzalkonium, an antibacterial preservative found in most over-the-counter prepared saline nasal spray products. Rhinitis medicamentosum means that the nose gets stuffy and congested after use of nose drops such as oxymetazoline (Afrin™). The more the nose drops are used, the more "rebound" when the drug wears off, that is, the worse the patient gets after the drops wear off, requiring more and more use of the drops. The drops become effectively addictive, and worse, the nose is always stuffy anytime the drug is not active in the nose.

Next, it was discovered that you could get rhinitis medicamentosum just form the Benzalkonium alone, as well as saline with Benzalkonium. So, it wasn't the nasal medication oxymetazoline that was responsible, but the Benzalkonium. The oxymetazoline did shrink the nose nicely, but the benzalkonim caused a rebound congestion.

These additive problems are so important that the Dannemiller Memorial Educational Foundation gives special training to doctors on this subject. This training emphasizes that if you are allergic or have an infection, the additives can be more irritating than when you are "normal".

Recent articles on the negative effects of Benzalkonium include:

Berg: Mucosa exposed to benzalkonium chloride showed squamus cell metaplasia ( the normal cells changed to undesirable cells). Benzalkonium chloride appears to be potentially toxic to the mucosa.

Steinsvag: benzalkonium chloride has toxic effects on human respiratory mucosa and human neutrophils. It destroyed mucosa and inhibited human neutrophil action.Benzalkonium chloride induces mucosal swelling, which explains why the presence of this preservative in a decongestant spray aggravates rhinitis medicamentosa.

Hoffman An irreversible cessation of ciliary movement was observed in ciliary cells exposed to nasal sprays containing Benzalkonium chloride As benzalkonium chloride can cause complete standstill of ciliary beat frequency in vitro in human nasal mucosa, we recommend that this preservative should not be used anymore in topical nasal medications.

An Additive-Free And Better Saline Solution

You can find solutions, enhanced nasal/sinus moisturizing formulas, which contain the same constituents as Boek's Locke-Ringer's Solution, including Soda Bicarbonate, Potassium and Calcium Chloride, and Salt. It doesn't contain any of the additives or preservatives now known to be harmful to the nose/ sinuses. By using a product free of irritating additives, in a more "friendly" mix, patients can benefit by use of moisturizing solutions.

Warm Saline

Hypertonic Saline

Hypertonic saline has been studied recently. There is evidence that it can "dry out" swollen tissues. By pulling liquid out of the tissue, this can thin the mucus according to some authors. It acts like sea water. Excessive hypertonic solution has been shown to impair movement of cilia. Many of the commercial preparations also contain additives that can irritate. Not everyone can use such a strong product in the nose. In one study to determine the use of hypertonic saline for acute common cold, no difference was found between this and regular saline. However, many patients complained of the burning from the hypertonic saline and wouldn't use it again.

Pediatric Use

Many children might have prevented chronic nasal/sinus problems by regular use of moisturizing spray. As a parent, I know how difficult it is to get a child to do "healthful habits".

First, an enhanced nasal/sinus moisturizing formula that is additive-free is more likely to be used by children because it doesn't burn. Using a spray bottle that is child size, and a solution that doesn't burn or cause other discomfort, I feel we can significantly reduce children's nasal problems. Find arefillable spray bottle thatis easy for the child to handle; the one I use has an oval surface that is ideal for the parent to put on a child's favorite stickers, (e.g. "Mickey Mouseš", "Pokemanš", etc.).

If you find that the saline nasal preparation you use burns or makes your condition worse, check the additives and preservatives. They may be the problem. Some of the preparations warn that they must be used at room temperature only. Check the label carefully as this too may be a problem - hot or cold may affect the additives / preservatives.

 ©2000, 2003 Dr. Murray Grossan

References:

Physiologic and hypertonic saline solutions impair ciliary activity in vitro. Boek WM. Laryngoscope, 109(3):396-9 1999 Mar
Physiological salt solution (0.9%) was found to slow cilia movement. Locke-Ringers solution with soda bicarbonate, potassium and calcium chloride, and salt was found best for cilia. "This solution is more appropriate than saline for nasal irrigator and nebulazation or sinus lavage." He reported complete ciliastasis with some hypertonic solutions, often within 5 minutes of exposure.

Benzalkonium chloride in a decongestant nasal spray aggravates rhinitis medicamentosa in healthy volunteers. Clin Exp Allergy.1995; 25:957-965
Benzalkonium chloride induces mucosal swelling, which explains why the presence of this preservative in a decongestant spray aggravates nasal/sinus symptoms

Effects of topical nasal steroids on human respiratory mucosa and human granulocytes in vitro. Steinsv¡ag S. Acta Otolaryngol (Stockh), 116(6):868-75 1996
"It is concluded that benzalkonium chloride has toxic effects on human respiratory mucosa and human neutrophils in vitro."

Effect of topical corticosteroids and topical antihistaminics on ciliary epithelium of human nasal mucosa in vitro. Hofmann T. HNO, 46(2):146-51 1998 Feb
"An irreversible cessation of ciliary movement was observed in all cells exposed to nasal sprays containing benzalconium chloride....." "we recommend that this preservative should not be used anymore in topical nasal medications."

The effects of topical nasal steroids on rat respiratory mucosa in vivo, with special reference to benzalkonium chloride. Berg OH. Allergy, 52(6):627-32 1997 Jun
"In conclusion, benzalkonium chloride appears to be potentially toxic to the nasal mucosa."

A clinical trial of hypertonic saline nasal spray in subjects with the common cold or rhinosinusitis. Adam P. Arch Fam Med, 7(1):39-43 1998 Jan-Feb
Hypertonic saline does not improve nasal symptoms or illness duration in patients with the common cold or rhinosinusitis. Thirty two percent of users noted burning and wouldn't use the product again.

 ©2000, 2003 Dr. Murray Grossan

Back to The On-Line ENT-Consultant Home Page