The invention provides compounds of general formula (I) wherein A, X, m, R.sup.1, N, R.sup.2, Z.sup.1, Z.sup.2, Q, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, t and R.sup.16 are as defined in the specification, processes for their preparation, pharmaceutical compositions containing them and their use in therapy ##STR00001##