Lower doses may improve outcomes in chronic disease

Chronic diseases can often be treated effectively with lower doses of medication than are commonly used, according to a ‘Viewpoint’ in the MJA. “Optimal drug dose – the best balance of benefit and risk – varies between individuals and may change over time,” professors Simon Dimmit and Hans Stampfer from the University of Western Australia wrote. “When treating chronic disease it is important to establish and maintain the optimal dose for each patient by close clinical monitoring.” While many drugs had a therapeutic dose plateau, the incidence and severity of adverse side effects tended to continue increasing with dose, they noted. Many classes of drugs had fairly flat dose-response curves, including SSRI antidepressants, opioids, antipsychotics and lithium. “The growing emphasis on aggressive treatment-to-target presents challenges for optimal dosing,” they said. Atorvastatin, for example, had an eight-fold recommended dose range, but clinicians had to judge whether additional side effects justified the incremental therapeutic benefits. Dosing recommendations were usually derived from short-term clinical trials in patients with acute or severe disease but there was little research to support the automatic application of these doses to long-term treatment and to the large numbers of patients with mild disease who were managed in primary care, the professors concluded. Medical Journal of Australia 2009; 191: 511-513.  ...