Drug- and toxin-induced pulmonary arterial hypertension: Current state of the literature

Drug- and toxin-induced pulmonary arterial hypertension (PAH) is an increasingly important sub-group of group 1 pulmonary hypertension (PH). In the last 60 years, we have seen the rise and fall of numerous prescription and illicit agents that have caused severe and deadly outbreaks of PAH. Currently, drugs and toxins are classified into “possible” and “definite” risk factors for PAH. While the exact mechanisms and pathogenesis of drug- and toxin-induced PAH are currently unknown, novel clinical and basic science studies are beginning to unravel the biologic factors and genetic underpinnings responsible for disease development. The clinical management of affected patients can be challenging as it is often difficult to identify patients early and demonstrate causality between drugs and PAH. Given the recent trends in drug utilization and development, it is highly likely that we will continue to identify new agents capable of causing pulmonary vascular disease. We must keep a high index of suspicion in order to identify patients and new compounds deemed definite or likely risk factors for PAH. Practicing pharmacovigilance, raising awareness, and working in tandem with PH patient associations and drug regulatory agencies may ultimately be our most effective strategy in preventing the next deadly outbreak of drug- and toxin-induced PAH.