Tolafentrine, a dual-selective phosphodiesterase 3/4 (PDE3/4) inhibitor, has been shown to have significant acute and chronic effects in a unilateral diacetamide-induced rat pulmonary hypertension model. Experiments show that long-term administration can significantly alleviate all unilateral bisacetamide-induced hemodynamic and gas exchange abnormalities, reduce right ventricular hypertrophy, and normalize pulmonary vascular remodeling changes[1].