Positive test results were obtained only in the in vitro CHO Sister Chromatid Exchange clastogenicity and in the Mouse Lymphoma Cell mutagenicity assays, using concentrations of HCTZ from 43 to 1300 mcg mL, and in the Aspergillums Nidulans nondisjunction assay at an unspecified concentration buy cialis canada pharmacy 29 This review suggests considerably more research is required, to examine the potential of triple or quadruple quarter dose combinations to determine whether they could provide substantial blood pressure lowering with little or no drug specific side effects, that is, more or less pure blood pressure lowering