Xerostomia is defined as the subjective sensation of dryness of the mouth.
Reduced or absent saliva flow may be caused by by medications, total body irradiation and oral graft versus host disease (GvHD). Medications can alter the composition and flow of saliva, radiation induced injury to the salivary glands can result in decreased saliva production and chronic fibrotic changes of the mucosa and adjacent salivary ducts may occur due to oral GvHD in patients undergoing haematopoietic stem cell transplant.
Onset of xerostomia is within days to weeks of commencing treatment. For some patients, this will be a temporary side effect from radiotherapy and the xerostomia should start to improve 6-12 weeks after treatment has finished. For others, this will be a permanent side effect.
- medications (e.g. chemotherapy, antiemetics, antihistamines, antidiarrhoeals, antianxiety drugs and opioid analgesics)
- radiation therapy
- oral GvHD.