Pharmaceutically active homo-dimers of opioid and other pharmaceutically active agents characterized by a single phenolic hydroxyl group wherein the respective monomers are ether-linked through such groups by an ethylene residue. The dimers share the receptor pharmacology of the corresponding monomer, in particular cases are non-absorbed, and the ether link of the dimers is particularly resistant to metabolism when administered to a subject, all conferring divers advantages relative to the corresponding monomers. Exemplary of the dimers are those of buprenorphine, naloxone, naltrexone, des-venlafaxine, albuterol and acetaminophen.