Selective phosphodiesterase-4 inhibitors

Selective phosphodiesterase-4 inhibitors increase cyclic adenosine-3′,5′-monophosphate (cAMP) levels, resulting in a broad spectrum of anti-inflammatory effects in almost all inflammatory cells. Selective phosphodiesterase-4 inhibitors are used in the treatment of severe Chronic Obstructive Pulmonary Disease (COPD) to reduce the risk of COPD exacerbations. They are not bronchodilators and therefore not indicated for the relief of acute bronchospasm.