The primary objective in the management of a chronic disease is to maximise therapeutic effectiveness, according to the general consensus among specialists. Recent market research has confirmed that a treatment's effectiveness is the primary consideration for neurologists' choice of therapy for multiple sclerosis (MS). Of the available disease-modifying therapies, interferon (IFN) beta appears to be consistently more efficacious than glatiramer acetate. High doses of therapy, and frequent administration of IFN beta should be used to provide maximal effects. This has been supported by a recent Class I comparative trial of two commercial preparations of IFN beta-1a. Preliminary results indicated significantly greater efficacy for IFN beta-1a (Rebif, Serono) 44 microg administered subcutaneously three times weekly (t.i.w.), over IFN beta-1 (Avonex, Biogen) 30 microg administered intramuscularly once weekly IFN beta-1a, 44 microg t.i.w., provides maximal efficacy for patients with relapsing forms of MS.