**4.2. Pre-injury medication usage**

As the population ages, increasing numbers of elderly are being prescribed a medication for chronic medical conditions. It was shown that medications (especially sedatives and hypnotics, antidepressants, and benzodiazepines [52]) are particularly complex risk factors for falls and the risk of falling increases with the number of medications taken [18]. Also, polypharmacy is associated with occurrence of drug–drug interactions and adverse drug reactions which are frequently encountered in the elderly [53]. B-adrenergic blocking agents may limit the tachycardia response which can result in undesirable decreased cardiac output and reduced tissue perfusion. Calcium-channel blockers may prevent peripheral vasoconstriction and contribute to produce hypotension. Chronic diuretic use may lead to elderly patients being chronically hypovolemic, hyponatremic and hypokalemic. Additionally, declines in renal and hepatic function may alter the metabolism and clearance of these drugs. The side effects, drug interactions should always be considered and potentially nephrotoxic drugs must be given in adjusted doses based on calculated creatinine clearance.
