title: The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials Studies of salivary flow in borderline hypertension: effects of drugs acting on structures innervated by the autonomic nervous system. Effects of furosemide and bendroflumethiazide on saliva flow rate and composition.
abstract: Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Salivary flow and the influence of drugs on this were studied in subjects with borderline hypertension and in normotensive subjects .  Saliva production at rest was lower in borderline hypertensive subjects than in normotensive subjects . Plasma catecholamine levels were similar in both groups of subjects studied . Intravenous injections of propranolol and phentolamine did not enhance saliva secretion in the borderline hypertensive group , whereas atropine caused the secretion to decrease in both groups . Intravenous infusions of neostigmine led to a dose-dependent increase of salivary flow . The dose-response curve for the stimulating effect of neostigmine on saliva production was shifted to the right in borderline hypertensive as compared with normotensive subjects . The results of the study support the assumption that in subjects with borderline hypertension parasympathetic influence on the salivary gl and s is reduced Aim of this study was to evaluate the effect on saliva flow rate and composition and on perceived xerostomia . The study used a Latin square design , all subjects being once daily ( at 7.00 a.m. ) taking the bendroflumethiazide ( 2.5 mg ) , furosemide ( 40 mg ) , or placebo , in a r and omised order . Each treatment period of 7 days was separated by wash-out periods of 14 days . Unstimulated and paraffin chewing stimulated whole saliva , and 3 % citric acid stimulated parotid and subm and ibular-sublingual secretion were collected twice daily , at 7.30 a.m. , with the patients in a fasting condition ( morning values ) , and at 10.30 a.m. , about 2 h after intake of a st and ard breakfast ( lunchtime values ) , on day 0 ( baseline ) , day 1 ( acute treatment ) , and day 7 ( chronic treatment ) . Saliva flow rates were measured and all four secretions were analysed for the concentration of sodium , potassium , chloride , and total protein . Xerostomia was assessed by means of a Visual Analogue Scale . Statistical analysis used the Wilcoxon signed rank test . For flow rate , only that of subm and ibular-sublingual secretion was affected , significantly so in the morning during chronic treatment with both drugs . In resting whole saliva the output of both sodium and chloride tended to decrease especially during treatment with bendroflumethiazide , while in subm and ibular-sublingual secretion the output of all the electrolytes was decreased , especially for potassium and chloride and during treatment with furosemide . Further , xerostomia tended to increase during treatment with furosemide , statistically significant at lunchtime during chronic treatment . In conclusion , this study has demonstrated a modest effect on salivary flow rate and a more pronounced effect on saliva composition , especially in subm and ibular-sublingual secretion during treatment of healthy volunteers with therapeutic doses of two different diuretics , encouraging clinical studies in hypertensive patients and basic research as to the presence of a thiazide sensitive Na-Cl cotransporter in human salivary gl and
target: The results of the included studies did not provide evidence to state that patients taking  antihypertensives suffer more xerostomia or hyposalivation than patients not taking them .
  The case-control studies showed great variability in salivary flow , but in this case most studies showed how salivary flow is lower in patients medicated with antihypertensive drugs .
background: The aims of this systematic review are ( 1 ) to compare the prevalence of xerostomia and hyposalivation between patients taking antihypertensive drugs with a control group ( CG ) , ( 2 ) to compare salivary flow rate between patients treated with a CG , and ( 3 ) to identify which antihypertensives produce xerostomia .