Spray Away Dry Mouth

Antidepressant induced dry mouth reduced with malic acid spray

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Dry mouth can go from uncomfortable to unbearable in a hurry. Certain medications can trigger dry mouth, but help may be found in the form of a plant-based spray.

In a recent clinical trial, researchers tested the use of a spray to relieve dry mouth resulting from antidepressant use.

The results showed that a spray with malic acid, xylitol and fluoride helped reduce dry mouth and increase saliva flow for six to seven hours.

"Tell your MD about any dry mouth symptoms."

Gerardo Gómez-Moreno, PhD, professor in the Department of Pharmacological Research in Dentistry at the University of Granada in Spain, led an experiment to use malic acid to relieve the anti-depressant side effect of dry mouth.

Malic acid is naturally produced by the body’s metabolism, but can also be found in certain fruits used in mouthwashes and skin care products. Malic acid is often used to make flavored candy and chips taste sour.

Dry mouth can be caused by a decrease in saliva flow or changes in the chemical make-up of the saliva, according to authors. The authors said people with dry mouth have reported trouble with chewing, swallowing and even speaking.

“Antidepressants are the most common group of [medications] inducing dry mouth,” said the authors.

Previous studies that have used malic or citric acid to reduce dry mouth resulted in weakened tooth enamel. More recent studies have shown that weakened tooth enamel from malic acid could be counteracted with a combination of xylitol and fluorides.

Xylitol is a no-calorie sweetener that can be harvested from produce, which has been shown to benefit dental health. Fluoride is used in toothpaste and other oral hygiene products to reduce tooth decay.

For this clinical trial, 70 people with dry mouth from antidepressant medications were split into two groups. People with other possible causes for dry mouth were excluded from the study.

The antidepressant prescriptions taken by participants included selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), tetracyclic antidepressants (TeCAs) and monoamine oxidase inhibitors (MAOIs).

Participants in the first group were given a spray bottle solution of 1 percent malic acid, 10 percent xylitol and 0.5 percent fluoride to use as needed for dry mouth for two weeks.

Participants in the second group (control group) were given a spray bottle with 10 percent xylitol and 0.5 percent fluoride, but no malic acid, to use as needed for dry mouth for two weeks.

Each participant was questioned about his or her dry mouth conditions before using the spray and after two weeks of using the spray. The researchers also measured each participant's salivation levels at the start of the study and again two weeks after using the mouth spray.

All 70 participants completed the trial.

The results showed 86 percent of people in the malic acid group experienced some level of improvement in dry mouth compared to only 14 percent of the control group.

The malic acid spray provided relief from dry mouth for an average of 21 minutes compared to eight minutes for the placebo spray. Participants in the malic acid group reported that they did not feel the need to re-spray for another six to seven hours compared to every four hours in the control group.

The authors concluded that a 1 percent malic acid spray could help reduce dry mouth side effects resulting from antidepressant use.

The results of this clinical trial match results from a previous study on the same subject.

Many over-the-counter dry mouth sprays are available at neighborhood drug stores or online. For more serious medical conditions that cause dry mouth, prescription medications are available.  

This study was published in the February issue of Depression and Anxiety.

The Regional Government of Spain, the Research Group Pharmacological Research in Dentistry and the Instituto de Salud Carlos III provided funding for this project. No conflicts of interest were reported.

Reviewed by: 
Review Date: 
April 7, 2013
Last Updated:
April 8, 2013