An alternative method of assessing changes in salivary flow: comparison of the effects of clonidine and tiamenidine (HOE 440).

An established method for collecting uncontaminated parotid saliva has been applied to assessment of salivary flow rate. Following single doses of 0.3 mg clonidine and 1.0 mg tiamenidine (HOE 440) changes in blood pressure, heart rate, sedation (assessed by a self-rating scale) and salivary flow were followed in nine normal subjects. Both drugs produced a fall in systolic and diastolic blood pressure, sedation, depression of salivary flow and a lowering of heart rate. These changes were maximal between 2 and 6 h and were more marked after clonidine than after tiamenidine. As tiamenidine 1.0 mg did not produce a hypotensive effect equivalent to clonidine 0.3 mg direct comparison of side-effects attributable to these agents proved difficult. The evidence suggests, however, that tiamenidine would cause sedation and reduction in salivary flow comparable to clonidine if given in an equivalent hypotensive dose.