The Communist attitude to drug use was characterised by the policy of ''strict execution, lenient punishment''. Despite widespread arrests and large anti-drug rallies, the number of actual drug offenders executed was relatively low, and the punishment of execution was generally reserved for high-level suppliers, not addicts.
The Chinese Government embarked on a National Drug Campaign from 1949 until 1952, with the goal of reducing opium use. The campaign utilised propaganda, rallies, rehabilitation centres, and waves of mass arrests, however very few executions. This was the only major anti-drug campaign enacted while Mao was in power.
At the peak of the campaign, the Communists directed that around 2% of drug offenders should be sentenced to execution, and authorised the execution of up to a dozen high level suppliers in strategically chosen cities. The actual figure of offenders sentenced to execution was around 1%, with the majority of offenders being sentenced to rehabilitation or periods of imprisonment.
The campaign was highly successful. It largely eliminated an endemic problem with opium addiction which both the Qing dynasty and Nationalist governments had unsuccessfully attempted to address.
Sources:
Anti-Drug Crusades in Twentieth-Century China: Nationalism, History, and State Building. Zhou Yongming
Opium Regimes: China, Britain, and Japan, 1839-1952 edited by Timothy Brook, Bob Tadashi Wakabayashi
Follow up: if true, what happened to those who chose rehab and relapsed? Also, have any countries adopted an approach specifically modeled after the Chinese program? (perhaps not as stringent a choice as death)