The present invention concerns compounds of formula (I), prodrugs, N-oxides, addition salts, quaternary amines, metal complexes and stereochemically isomeric forms thereof wherein -a.sup.1=a.sup.2-a.sup.3=a.sup.4-represents a radical of formula --CH.dbd.CH--CH.dbd.CH--; --N--CH--CH.dbd.CH--; --CH.dbd.N--CH.dbd.CH--; --CH.dbd.CH--N.dbd.CH--; --CH.dbd.CH--CH.dbd.N--; wherein each hydrogen atom may optionally be substituted; Q is a radical of formulae (b-1), (b-2), (b-3), (b-4), (b-5), (b-6), (b-7) and (b-8), wherein Alk is C.sub.1-6alkanediyl; Y.sup.1 is a bivalent radical of formula --NR.sup.2-- or --CH(NR.sup.2R.sup.4)--; X.sup.1 is NR.sup.4, S, S(.dbd.O), S(.dbd.O).sub.2, O, CH.sub.2, C(.dbd.O), CH(.dbd.CH.sub.2), CH(OH), CH(CH.sub.3), CH(OCH.sub.3), CH(SCH.sub.3), CH(NR.sup.5aR.sup.5b), CH.sub.2--NR.sup.4 or NR.sup.4--CH.sub.2; X.sup.2 is a direct bond, CH.sub.2, C(.dbd.O), NR.sup.4, C.sub.1-4alkyl-NR.sup.4, NR.sup.4--C.sub.1-4alkyl, t is 2 to 5; u is 1 to 5; v is 2 or 3; and whereby each hydrogen in Alk and in (b-3), (b-4), (b-5), (b-6), (b-7) and (b-8), may optionally be replaced by R.sup.3: provided that when R.sup.3 is hydroxy or C.sub.1-6alkyloxy, then R.sup.3 cannot replace a hydrogen atom in the a position relative to a nitrogen atom; G is a direct bond or optionally substituted C.sub.1-10alkanediyl; R.sup.1 is an optionally substituted bicyclic heterocycle; R.sup.2 is hydrogen, formyl, C.sub.1-6alkylcarbonyl, Hetcarbonyl, pyrrolidinyl, piperidinyl, homopiperidinyl, C.sub.3-7cycloalkyl or C.sub.1-10alkyl substituted with N(R.sup.6).sub.2 and optionally with another substituent; R.sup.3 is hydrogen, hydroxy, C.sub.1-6alkyl, C.sub.1-6alkyloxy, aryl C.sub.1-6alkyl or aryl C.sub.1-6alkyloxy, R.sup.4 is hydrogen, C.sub.1-6alkyl or aryl C.sub.1-6alkyl; R.sup.5a, R.sup.5b, R.sup.5c and R.sup.5d are hydrogen or C.sub.1-6alkyl; or R.sup.5a and R.sup.5b, or R.sup.5c and R.sup.5d taken together from a bivalent radical of formula --(CH.sub.2).sub.5- wherein S is 4 or 5; R.sup.6 is hydrogen, C.sub.1-4alkyl, formyl, hydroxy C.sub.1-6alkyl, C.sub.1-6alkylcarbonyl or C.sub.1-6alkyloxycarbonyl; aryl is optionally substituted phenyl; Het is pyridyl, pyrimidinyl, pyridazinyl, pyridazinyl; as respiratory syncytial virus replication inhibitors; their preparation, compositions containing them and their use as a medicine.