Abstract: This invention concerns the use of a compound for the manufacture of a medicament for the prevention of HIV infection via sexual intercourse and related intimate contact between partners, wherein the compound is a compound of formula a N-oxide, a pharmaceutically acceptable addition salt, a quaternary amine and a stereochemically isomeric form thereof, wherein the ring containing -a1=a2-a3=a4- and -b1=b2-b3=b4- represents phenyl, pyridyl, pyrimidinyl, pirazinyl, pyridazinyl; n is 0 to 5; m is 1 to 4; R1 is hydrogen; aryl; formyl; C1-6alkylcarbonyl; C1-6alkyl; C1-6alkyloxycarbonyl; substituted C1-6alkyl, C1-6alkylcarbonyl, C1-6alkyloxycarbonyl, C1-6alkylcarbonyloxy; substituted C1-6alkyloxyC1-6alkylcarbonyl; R2 is hydroxy, halo, optionally substituted C1-6alkyl, C3-7cycloalkyl, optionally substituted C2-6alkenyl, optionally substituted C2-6alkynyl, C1-6alkyloxy, C1-6alkyloxycarbonyl, carboxyl, cyano, nitro, amino, mono- or di(C1-6alkyl)amino, polyhalomethyl, polyhalomethyloxy, polyhalomethylthio, —S(?O)pR6