PDE5A and Myalgia: However, the absence of PDE11 in cardiac myocytes46 together with the lack of any obvious neurological disturbance or myalgia (PDE11-dependent side-effects) would suggest that despite the plasma concentration of tadalafil used (~50 nmol/l) causing complete inhibition of PDE5 (IC50 range 0.94–9.4 nmol/l)42,47, the approximate 40%, inhibition of PDE11 is not underpinning the cardioprotective effects observed in the present study.