Potential drug interactions in elderly cancer patients.

INTRODUCTION: Drug interaction constitutes a major challenge in elderly cancer patients. This study investigated the number and types of medications patients and potential drug interactions in these patients. METHODS: Treatments received by 105 cancer outpatients aged ≥70 years were analyzed using the French Thesaurus to identify drug-drug interactions according to four levels: contraindication, concomitant use not recommended, concomitant medications requiring precautions and concomitant medications to be taken into account. RESULTS: The mean number of medications per patient was 4.7 (range: 0-14). Among 97 patients taking ≥2 drugs, 45 potential interactions were identified, occurring in 32 patients. No contraindication, 2 cases of concomitant use not recommended, 9 cases requiring precautions (20%) and 34 cases of concomitant medications to be taken into account were identified. Drug interactions caused respiratory distress and increased bleeding risk. CONCLUSION: Drug interactions are common in the elderly, but almost half of interactions were moderate.

[The risk of falling due to benzodiazepine administration, alone or in combination, in elderly subjects]. / Le risque de chutes lié à l'administration de benzodiazépines seules ou associées, chez le sujet âgé.

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.