[Latin-American Consensus on Difficult-to-Control Asthma. 2008 Update]

Abstract

Asthma, which is more of a syndrome than a disease, usually responds to inhaled corticosteroid treatment, with or without the addition of long-acting beta-agonists. However, in a certain group of patients asthma cannot be controlled despite administering appropriate drugs at high doses. Difficult-to-control asthma cases are the target of this consensus meeting. Clinical practice guidelines and consensus on this subject already exist, so we must emphasize that the objective of this document is to review said guidelines and adapt them to regional situations. It is also necessary to update the guidelines, as new treatment alternatives have appeared in our countries. Difficult-to-control asthma has many different names, such as severe, serious, difficult, refractory, unstable, life-threatening, corticoid-resistant, and corticoid-dependent asthma, among others. The prevalence of difficult-to-control asthma has not clearly been established, but several publications estimate it to represent 5% of the asthma population. However, the significant impact on asthma-related direct and indirect costs and the quality of life impairment in this patient population have been clearly shown. The Latin American Consensus on Difficult-to-Control Asthma submits the following definition: "Inadequately-controlled asthma existing despite appropriate treatment strategy adjusted to the clinical severity level (level 4 or higher of the Global Initiative for Asthma [GINA]), indicated by a physician and administered for at least six months". The correct diagnosis of difficult-to-control asthma usually is made when there is no response to adequate treatment adjusted to the clinical severity level. However, many conditions can mimic difficult-to-control asthma, while others can exacerbate it. Therefore, in order to ensure a correct diagnosis, certain requirements - systematic assessments - must be met which confirm the asthma diagnosis and rule out other conditions. The therapeutic approach to difficult-to-control asthma includes pharmacological and non-pharmacological aspects. Patient assessment and treatment should be conducted at appropriately-equipped sites and by specialists experienced in this field. In terms of drug therapy, we specifically looked at the position described in the guidelines regarding the different treatment options. At level 5 of its treatment strategy, GINA recommends adding oral glucocorticoids or omalizumab, albeit this combination is associated with serious undesirable effects, as per GINA itself. The recent Expert Panel Report 3 (2007) from the National Asthma Education and Prevention Program (NAEPP) proposes a different strategy. The treatment approach is divided into six levels: omalizumab is recommended as additional therapy at level 5 in patients with allergic asthma caused by perennial allergens, while oral corticoids are indicated at level 6 and can be used in combination with all level 5 control medications. Patients with difficult-to-control asthma require close follow-up with frequent reviews of their clinical and therapeutic condition and must have a written tailored action plan based on their asthma symptoms and home peak expiratory flow results.