What do systematic reviews say?

Gum chewing (sugar-free) vs No chewing gum

Across 19 studies the effect of gum chewing on stimulated and/or unstimulated salivary flow rate was mixed (9 positive, 10 no effect); this broad outcome was not meta-analyzed.

• The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes

  Various (single session to 12 months) · Haemodialysis units, elderly / geriatric care, cancer and palliative care, and xerostomia / hyposalivation clinics (studies from multiple countries)
  Narrative vote-count: of 19 studies measuring stimulated and/or unstimulated saliva flow rate, 9 found a positive effect of gum chewing [17,18,22,24,27,35,36,38,39] and 10 detected no effect…
  19 studies
  GRADE not reported

Daily chewing gum for 2 weeks or longer vs No gum chewing or control

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• The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes

  2 to 12 weeks · Meta-regression slope for change in standardized salivary flow rate per additional week of chewing · Meta-regression by chewing duration
  SMD per week 0.06
  6 studies · 291 participants
  GRADE not reported

Gum chewing (sugar-free) vs No chewing gum

In elderly and medically compromised people with xerostomia, chewing sugar-free gum daily for two or more weeks produces a small but statistically significant increase in unstimulated whole salivary flow rate versus no gum (SMD 0.44, 95% CI 0.22 to 0.66); certainty of evidence was not formally graded.

• The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes

  Gum chewed daily for >=2 weeks (2 to 12 weeks; multiple time points for Kim and Ozen) · Haemodialysis units, elderly / geriatric care, cancer and palliative care, and xerostomia / hyposalivation clinics (studies from multiple countries)
  SMD 0.44 [0.22, 0.66]
  6 studies · 291 participants
  GRADE not reported

Polaprezinc vs Azulene oral rinse

The review found no eligible studies for this question.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes
  No data on salivary flow rates were reported.
  0 studies
  No studies found

Bethanechol vs Artificial saliva

Bethanechol led to higher salivary flow rate (unstimulated, ml/min) compared with artificial saliva; GRADE not reported.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  End of RT
  MD 0.12 [0.01, 0.23]
  1 study · 36 participants
  GRADE not reported
• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  8 to 40 weeks postRT
  MD 0.07 [-0.02, 0.16]
  1 study · 33 participants
  GRADE not reported

Chinese medicine vs no treatment/placebo

Chinese medicine led to higher salivary flow rate (stimulated) compared with no treatment/placebo; GRADE not reported.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  End of RT
  MD 0.09 [0.03, 0.15]
  1 study · 50 participants
  GRADE not reported

Amifostine vs no treatment/placebo

It is very uncertain whether amifostine changes salivary flow rate (mg/5 min, unstimulated) compared with no treatment/placebo (very low certainty).

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  12 months postRT
  MD 0.32 [0.09, 0.55]
  1 study · 27 participants
  Very low
• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  End of RT
  MD 0.34 [0.07, 0.61]
  83 participants
  GRADE not reported

Keratinocyte growth factor (KGF; palifermin or repifermin), intravenous vs placebo

The review found no eligible studies for this question.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes
  None of the trials evaluating palifermin provided data on salivary flow rates.
  0 studies
  No studies found

Antiseptic mouthrinse vs placebo

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes
  Salivary flow rate was only reported during radiotherapy (i.e. not at any of the time points of interest); no usable data (Lanzos 2010)
  1 study
  GRADE not reported

Pilocarpine vs no treatment/placebo

It is very uncertain whether pilocarpine changes salivary flow rate (unstimulated) compared with no treatment/placebo (very low certainty).

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  Up to and including 3 months postRT
  MD -0.06 [-0.23, 0.11]
  1 study · 24 participants
  Very low

Amifostine (intravenous) vs Amifostine (subcutaneous)

The review found no eligible studies for this question.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes
  No salivary flow rate data related to routes of administration of amifostine were reported.
  0 studies
  No studies found

Bethanechol vs Artificial saliva

Bethanechol led to higher salivary flow rate (stimulated, ml/min) compared with artificial saliva; GRADE not reported.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  8 to 40 weeks postRT
  MD 0.21 [0.01, 0.41]
  1 study · 29 participants
  GRADE not reported
• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  End of RT
  MD 0.13 [-0.03, 0.29]
  1 study · 32 participants
  GRADE not reported

Bethanechol vs placebo

Bethanechol showed no clear difference in salivary flow rate (stimulated, ml/min) compared with placebo; GRADE not reported.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  2 months postRT
  MD 0.15 [-0.03, 0.33]
  1 study · 97 participants
  GRADE not reported

Pilocarpine vs no treatment/placebo

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  Any time point
  No evidence of a difference between treatment groups for stimulated salivary flow at any time point (Analysis 1.5)
  8 studies
  GRADE not reported

Bethanechol vs placebo

Bethanechol led to higher salivary flow rate (unstimulated, ml/min) compared with placebo; GRADE not reported.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  2 months postRT
  MD 0.19 [0.06, 0.32]
  1 study · 97 participants
  GRADE not reported

Amifostine 200 mg/m2 three times weekly vs Amifostine 200 mg/m2 five times weekly

The review found no eligible studies for this question.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes
  No salivary flow rate data related to the effectiveness of different doses of amifostine were reported.
  0 studies
  No studies found

Amifostine vs no treatment/placebo

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  End of RT to 12 months postRT
  Insufficient evidence of a difference in stimulated salivary flow at any time point: end of RT MD -0.09 (95% CI -1.48 to 1.30); 3 months MD 0.38 (95% CI -1.43 to 2.19); 12 months MD 0.82 (95% CI -0.47 to 2.11);…
  2 studies
  GRADE not reported

Amifostine vs no treatment/placebo

Amifostine led to higher salivary flow rate (incidence of > 0.1 g saliva/5 min, unstimulated) compared with no treatment/placebo; GRADE not reported.

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  12 months postRT
  RR 1.45 [1.13, 1.86]
  1 study · 175 participants
  GRADE not reported

Venalot Depot (coumarin plus troxerutin) vs placebo

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes
  Sialometric data dropped to an unmeasurable level in both groups; abandoned as a marker of efficacy (Grotz 2001)
  1 study
  GRADE not reported

Biperiden plus pilocarpine vs no treatment

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes

  End of RT
  Insufficient evidence, from a single trial of 60 participants, to determine the effect on unstimulated salivary flow rate at the end of RT (Rode 1999; Analysis 2.1)
  1 study · 60 participants
  GRADE not reported