THE INVENTION RELATES TO A MEDICAMENT FOR TREATING CHRONIC: OBSTRUCTIVE PULMONARY DESEASE COMPRISING AS ACTIVE INGREDIENTS A CARBOSTYRIL DERIVATIVE OF FORMULA (1): WHEREIN A IS A LOWER ALKYLENE GROUP, P IS A CYCLOALKYL GROUP, THE BONDING BETWEEN 3- AND 4-POSITIONS OF THE CARBOSTYRIL SKELETON IS A SINGLE BOND OR A DOUBLE BOND,OR A SALT THEREOF; AND PROBUCOL. FIGURE 1