Older people and polypharmacy
Practice questions with explanations

D. Reduced baroreflex sensitivity, arterial stiffening and lower plasma volume mean less compensation for vasodilation or volume loss

The physiological reserve that protects a younger person is diminished, so the same dose produces symptoms. Alpha-blockers, nitrates, diuretics, antihypertensives, antidepressants and antipsychotics all contribute, often together, and measuring lying and standing blood pressure identifies who is affected before they fall.

C. A reduced proportion of body water gives a smaller volume of distribution and higher concentrations for a given dose

Ageing brings a fall in total body water and lean mass and a rise in fat, so hydrophilic drugs are distributed into a smaller space while lipophilic drugs such as diazepam gain a larger reservoir and a longer half-life. Renal clearance falls, hepatic first-pass metabolism declines and albumin tends to be lower. Together these argue for lower starting doses and slower titration.

D. Individualise the target, weighing stroke prevention against falls, dizziness and treatment burden, and check for postural drop

Treating hypertension benefits older people, including the very old, but frailty changes the balance, and a patient who faints on standing has been harmed rather than helped. Measuring lying and standing pressure is part of the assessment. The number that matters is the one achieved without symptoms, and deprescribing is considered where the burden outweighs the benefit.