Impact of TCAs and Gabapentin on Saliva and BMI in Adults With Xerostomia.

BACKGROUND

Tricyclic antidepressants (TCAs) and gabapentin are commonly associated with xerostomia and weight gain, a pattern that remains underexplored in the context of comorbidities and demographic variables in real-world observational samples.

OBJECTIVES

To evaluate the associations of TCA and gabapentin use with body mass index (BMI) and a comprehensive panel of oral dryness outcomes, and to examine the influence of demographic and clinical variables on these measures.

METHODS

This study included 147 adults aged 45-64 years with medication-related xerostomia. Oral dryness was assessed using unstimulated whole saliva (UWS), minor salivary flow (MSF) and the Xerostomia Inventory (XI). Data on medication exposure, anticholinergic burden, BMI and comorbidities were obtained from electronic records and standardized questionnaires. Associations were tested using multivariable linear regression models.

RESULTS

Use of TCAs or gabapentin was not independently associated with BMI or oral dryness after adjustment for comorbidities. Female sex, greater anticholinergic burden and conditions such as gastroesophageal reflux, obstructive sleep apnea and thyroid disease showed stronger associations with reduced salivary flow (< 0.30 mL/min) and higher XI scores. Race and depression were also independently related to BMI and XI scores.

CONCLUSION

Oral dryness (< 0.30 mL/min) and BMI outcomes in medication-related xerostomia were more strongly associated with demographic and clinical variables than with the utilization of TCAs or gabapentin. These findings underscore the importance of conducting longitudinal research to investigate the temporal and contextual relationships between BMI, salivary measures and xerostomia in real-world clinical populations. However, a medication-matched control group without xerostomia was not included, which limits the interpretation of the results.