What do systematic reviews say?

Prophylactic valaciclovir (lower dose) vs Prophylactic valaciclovir (higher dose)

Prophylactic valaciclovir (lower dose) showed no clear difference in presence/absence of HSV oral lesions compared with prophylactic valaciclovir (higher dose); GRADE not reported.

• Interventions for the prevention and treatment of herpes simplex virus in patients being treated for cancer 2009 · Cochrane All outcomes
  RR 0.23 [0.05, 1.03]
  2 studies · 181 participants
  GRADE not reported

Prophylactic valaciclovir (lower dose) vs Prophylactic valaciclovir (higher dose)

• Interventions for the prevention and treatment of herpes simplex virus in patients being treated for cancer 2009 · Cochrane All outcomes
  Orlowski 2004: 182 throat swabs performed for patients receiving 500 mg of valaciclovir (n = 40) and 198 swabs for those receiving 1000 mg (n = 41); all of the cultures proved negative (1 trial, 81; not estimable).
  1 study · 81 participants
  GRADE not reported

Prophylactic valaciclovir (lower dose) vs Prophylactic valaciclovir (higher dose)

• Interventions for the prevention and treatment of herpes simplex virus in patients being treated for cancer 2009 · Cochrane All outcomes
  One study reported adverse effects (Warkentin 2002). Twenty patients allocated to receive high dose valaciclovir reported adverse effects (42%); for the low dose group this number was 27 (52%). Adverse effects were…
  1 study · 100 participants
  GRADE not reported

Intestinal trefoil factor (ITF), lower dose (336 mg) vs Intestinal trefoil factor (ITF), higher dose (2688 mg)

• Interventions for preventing oral mucositis in patients with cancer receiving treatment: cytokines and growth factors 2017 · Cochrane All outcomes
  Insufficient evidence to determine whether lower (336 mg) or higher (2688 mg) dose performs better (Analyses 11.1 to 11.3); no pooled estimate reported
  1 study · 66 participants
  GRADE not reported