Let \(B, D \subset \overline{\mathbb C}\) be plane domains with a Green function and let \(w=f(z)\) be a meromorphic \(p\)-valent function which maps \(B\) into \(D\). An inequality involving quadratic forms, whose coefficients are either values of the Green functions or the inner radii of the domains \(B\) and \(D\), is extended to the case of arbitrary real variables. As a consequence, inequalities for meromorphic \(p\)-valent functions in the unit disc are obtained.