The present invention relates to the use of one or more compounds selected from the following classes of biologically active agents: an ±-adrenergic antagonist, an anthelmintic agent, an antifungal agent, an antimalarial agent, an antineoplastic agent, an antipsychotic agent, an antioxidant, a vasodilator and/or a vitamin, or a pharmaceutically acceptable derivative thereof, for use in the treatment of a microbial infection and in particular for killing multiplying, non-multiplying and/or clinically latent microorganisms associated with such an infection.