Quinacrine is a compound with multiple actions that is commonly used as an anti-protozoal agent. It has also been shown to be a highly potent autophagy inhibitor, although the dose required to achieve this effect is considerably cytotoxic (LD50 = 2.5 µM). Quinacrine analog 34 is a derivative of quinacrine that was designed with an improved cell viability profile (LD50 = 27 µM) to inhibit autophagy. At a minimum concentration of 0.5 µM, this compound has been shown to increase the protein levels of the autophagy biomarker LC3-II and to induce lysosome deacidification.