Long-term safety, durability of response, cessation and switching of biologics.

PURPOSE OF REVIEW: Severe asthma patients suffer from decreased quality of life, and increased asthma symptoms, exacerbations, hospitalizations, and risk of death. Biologics have revolutionized treatment for severe asthma. However, with multiple biologic agents now available, clinicians must consider initial selection the long-term effectiveness of biologics. Additionally, patients have overlapping eligibilities and clinicians may consider switching between biologics for improved response. Finally, careful assessment of biologics cessation is needed for severe asthma patients who depend on these add-on therapies for asthma control. RECENT FINDINGS: Evidence for long-term durability and safety varies by biologic agent. In general, initial benefits noted from these agents (ex. exacerbation reduction) is, at minimum, sustained with long term use. Rates of adverse events and serious adverse events, including those requiring cessation of a biologics are low with long term use. Further studies are needed to understand the development of antidrug antibodies but currently their prevalence rates are low. Adverse events and insufficient efficacy are common reasons for biologic cessation or switching. Discontinuation maybe associated with waning of benefits but can be considered in certain situations. Biologic switching can be associated with improved asthma control. SUMMARY: Biologics are safe and effective long-term therapies for the management of asthma. Discontinuation must be carefully considered and if possible avoided. Reasons for insufficient efficacy must be evaluated and if needed, biologic switching should be considered.

Lung Effects of Household Air Pollution.

Biomass fuel smoke, secondhand smoke, and oxides of nitrogen are common causes of household air pollution (HAP). Almost 2.4 billion people worldwide use solid fuels for cooking and heating, mostly in low- and middle-income countries. Wood combustion for household heating is also common in many areas of high-income countries, and minorities are particularly vulnerable. HAP in low- and middle-income countries is associated with asthma, acute respiratory tract infections in adults and children, chronic obstructive pulmonary disease, lung cancer, tuberculosis, and respiratory mortality. Although wood smoke exposure levels in high-income countries are typically lower than in lower-income countries, it is similarly associated with accelerated lung function decline, higher prevalence of airflow obstruction and chronic bronchitis, and higher all-cause and respiratory cause-specific mortality. Household air cleaners with high-efficiency particle filters have mixed effects on asthma and chronic obstructive pulmonary disease outcomes. Biomass fuel interventions in low-income countries include adding chimneys to cookstoves, improving biomass fuel combustion stoves, and switching fuel to liquid petroleum gas. Still, the impact on health outcomes is inconsistent. In high-income countries, strategies for reducing biomass fuel-related HAP are centered on community-level woodstove changeout programs, although the results are again inconsistent. In addition, initiatives to encourage home smoking bans have mixed success in households with children. Environmental solutions to reduce HAP have varying success in reducing pollutants and health problems. Improved understanding of indoor air quality factors and actions that prevent degradation or improve polluted indoor air may lead to enhanced environmental health policies, but health outcomes must be rigorously examined.