FREMGANGSMAADE TIL SVANGERSKABSFOREBYGGELSE

This invention relates to the use of a bisbiguanide compound of the formula:wherein either:(i) R1 and R3, which may be the same or different, are each a phenyl radical which is substituted by alkyl, alkoxy, nitro or halogen, R2 and R4 are both hydrogen, and A is a 3-9C polymethylene diradical, wherein the polymethylene chain may be interrupted by oxygen atoms and/or by aromatic nuclei; or(ii) the bivalent bridge A is:(a) alkylene of from 2 to 12 carbon atoms having the valence bonds attached to different carbon atoms,(b) -(CH2)m-X-(CH2)n- wherein m and n each represent an integer from 2 to 6 and Y is O or S,wherein Z and Z1 are each alkylene of from 1 to 3 carbon atoms,wherein Q is-O-,-S-,-SO-or-SO2-, orR1 and R3 are each:(a) alkyl of from 6 to 16 carbon atoms, or(b) alkyl-Y-alkylene, wherein Y is O or S and the alkyl and alkylene radicals together contain 3 to 15 carbon atoms; andR2 and R4 are each hydrogen or 1-6C alkyl; or an acid addition salt thereof.