In contrast to Bay K8644, which is not for clinical use, ambroxol is a frequently used mucolytic drug that triggers lysosomal secretion by mobilizing calcium from acidic calcium stores.[2] This effect does most likely not occur by a direct interaction between the drug and a lysosomal calcium channel, but indirectly by neutralizing the acidic pH within lysosomes. Calcium permeable ion channels in lysosomal membranes that may be activated by a luminal pH increase include two pore channels (TPCs), mucolipin TRP channels (TRPMLs) and purinergic receptors of the P2X channel type.[3][4]