Isoquinoline derivatives of the formula: ##STR1## wherein A represents pyrid-3-yl, isoquinol-5-yl or a 3-alkylisoquinol-5-yl radical in which the alkyl moiety contains 1 to 10 carbon atoms, are new compounds, possessing useful pharmacological properties. They are particularly valuable as analgesic, anti-inflammatory and antipyretic agents.