If you ask to the old school mafiosi was after the drugs replaced the cigarette traffick,but the facts are different.
Michele Navarra corleone boss in 1948 killed with an inection (he was a doctor) Giuseppe Letizia a 13 y old that watched the whacking of placido rizzotto a trade unionist on the orders of navarra in 1948.

The no kill women or children rule is made to be broken when the circumstances requires.

Little curiosity: the 1980 movie Luca il Contrabbandiere aka Contraband was financed, said unbeknownst to the director, with money and by the provision of the fleet of motorboats called blue hulls that is seen in the movie.The reason was that the old school camorristi want the people think that they was a gentlemens when the drug dealers were sociopathic killers.