<p>The surge of electronic cigarette use in Australia, especially amongst the younger population, raises significant concerns about its impact on respiratory health. This review focuses on the detrimental effects of vaping on pulmonary function, delving into oxidative stress, ventilation–perfusion mismatching, as well as cellular damage. Our findings show that e-cigarette use adversely affects the pharmacokinetics of inhaled therapies, reducing efficacy through impaired drug distribution, clearance and absorption, as well as alterations in metabolism. These negative effects mirror the impacts of traditional cigarette smoking, posing a severe health risk not only to individuals who vape, but also to those with pre-existing respiratory conditions. Despite its perception as a safer alternative, its consequence on pulmonary health is becoming increasingly evident with issues such as nicotine addiction and emerging evidence that even short-term exposure to e-cigarette aerosols impairs lung function, potentially paving the way for chronic respiratory diseases. This underscores an urgent need for further research on its long-term implications, particularly for individuals relying on inhalation therapies, emphasising the need for informed public health strategies and guiding clinical practice to safeguard respiratory health in this rapidly evolving landscape.</p>