The present invention is directed to 2H isotope enhanced ambroxol (“isotope enhanced ambroxol”) and its use in the treatment of autophagy infections, especially mycobacterial and other infections, disease states and/or conditions of the lung, such as tuberculosis, especially including drug resistant and multiple drug resistant tuberculosis. Pharmaceutical compositions comprising isotope enhanced ambroxol, alone or in combination with an additional bioactive agent, especially rifamycin antibiotics, including an additional autophagy modulator (an agent which is active to promote or inhibit autophagy) are also disclosed. These compositions are useful against an autophagy mediated disease state and/or condition), especially an autophagy mediated disease state and/or condition which occurs in the lungs.