Researchers from the universities of Granada and Murcia have confirmed the effectiveness of a spray containing 1% malic acid, which greatly improves xerostomia, or dry mouth, caused by antidepressants. This product, combined with xylitol and fluorides, in a spray format, stimulates saliva production in patients with this condition, thus improving their quality of life.
Xerostomia is a dry mouth sensation that patients have, often caused by reduced salivary secretion or biochemical changes in the saliva itself. Patients with xerostomia often find difficulty in chewing, swallowing or even talking. It is a subjective sensation, while hyposalivation refers to an actual reduction in salivary flow, meaning that it is objective and, therefore, quantifiable.
As the main author of this study, University of Granada lecturer, Gerardo Gomez Moreno, explains, one of the main causes of dry mouth is the consumption of different medications. "There are over 500 drugs, belonging to 42 pharmacological groups, which can provoke xerostomy as a side effect. Those that are most related are antidepressants, the prescription of which has increased over recent years, thus leading to a higher number of patients with xerostomy from taking antidepressive drugs, above all in 45-50 year olds."
Clinical trial using 70 patients
The University of Granada research was carried out in a double-blind randomized clinical trial on 70 patients diagnosed with antidepressant-induced xerostomia, split into two (2) groups. The first group of 35 patients took a sialogogue mouth spray (1% malic acid), while the second group – also consisting of 35 patients – received a placebo. Both products were applied on demand over two (2) weeks. To check the xerostomia both before and after applying both the product and the placebo, the researchers used a specific questionnaire, called the Dry Mouth Questionnaire (DMQ).
Gomez Moreno points out that are various therapeutic possibilities for treating xerostomy (sialogogues, salivary substitutes, other general treatments), "although the effectiveness of many of them are controversial. For example, some studies have described citric and malic acid as salivary stimulants, even though, for years, their use was rejected due to the possible de-mineralizing effect on tooth enamel." However, recent research has shown that there is a reduction in the potential demineralizing effect of malic acid when used in the correct concentration and when combined with xylitol and fluorides.
The University of Granada researchers, who belong to the "Pharmacological Research Group into Dentistry CTS-654," backed by the Andalusian Regional Government, have published their results in the Official American Journal on Depression and Anxiety.
Gomez-Moreno G , Aguilar-Salvatierra A, Guardia J, Uribe-Marioni A, Cabrera-Ayala M, Delgado-Ruiz RA, Calvo-Guirado JL.The efficacy of a topical sialogogue spray containing 1% malic acid in patients with antidepressant-induced dry mouth: a double-blind, randomized clinical trial. Depression and Anxiety. 2013;30(2):137-142.