  The strong OZI allowed decays of the first radial excited states $B(2S)$ and
$D(2S)$ are studied in the instantaneous Bethe-Salpeter method, and by using
these OZI allowed channels we estimate the full decay widths:
$\Gamma_{B^0(2S)}=24.4$ MeV, $\Gamma_{B^+(2S)}=23.7$ MeV,
  $\Gamma_{D^0(2S)}=11.3$ MeV and $\Gamma_{D^+(2S)}=11.9$ MeV.
  We also predict the masses of them: $M_{B^0(2S)}=5.777$ GeV,
$M_{B^+(2S)}=5.774$ GeV, $M_{D^0(2S)}=2.390$ GeV and $M_{D^+(2S)}=2.393$ GeV.
