Gerontology and drug development: The challenge of the senescent cell

The efficacy of new pharmaceuticals is considerably more difficult to estimate before use in the elderly than in young patients, particularly because clinical trials frequently involve young volunteers and because elderly patients on multiple treatments are at greater risk of adverse side-effects. There is an urgent need to understand the basic processes of senescence, and a practical requirement to deal with their consequences. Here, the authors review current understanding of the ageing process, summarize the experimental data supporting a link between senescence in cell cultures and ageing in the various tissues of the body, examine the changes that occur in the senescent cell from a pharmacological perspective and highlight possible improvements to existing in vitro screens for drug efficacy.