[The risk of falling due to benzodiazepine administration, alone or in combination, in elderly subjects].

Benzodiazepines are well tolerated by young adults whereas in elderly people they are less safe and globally induce more central nervous system side-effects and falls. Falls result from a decrease of vigilance and an alteration of postural reflex. This latter includes the reception of sensory information and central integration modulated mainly by dopaminergic D2 receptors and motor stimulation. Benzodiazepines act simultaneously on the three stages, decreasing their efficacy. The risk increases when certain other drugs are coprescribed, especially synergistic drugs such as another psycholeptic drug, an aminoside or a centrally active antihypertensive drug. Thus their co-prescription with a benzodiazepine increases the risk of falls. The pharmacokinetic parameters of benzodiazepines may be modified or remain constant during ageing. The choice of molecules whose parameters do not vary seems advisable. Whatever the selected benzodiazepine, it is obvious that it must be administered at the lowest possible dose, this dose being increased only if necessary, the overall prescription being time limited.