“I’m not thirsty doctor, you have to tell me to drink, otherwise I don’t think about it.” Dr. Renaud Ferrier, general practitioner and member of the URPS liberal doctors Paca, is regularly faced with this answer when he asks his elderly patients about their water consumption. “Physiological alert mechanisms are altered by age; seniors do not necessarily feel the need to drink, hence a higher risk of dehydration than the general population”, comments the health professional. And he warns the (very many) seniors treated with anti-hypertensives.
“ The mode of action of some of these drugs intended to lower the pressure in the arteries is through an increase in the production of urine. Taken during hot weather, they increase the harmful effects of high temperatures on the body.
It calls on those concerned to approach their attending physician – if the latter has not already done so – so that he can adapt the treatment. “We have drugs that keep the beneficial effect on hypertension, but without the so-called diuretic part.”
Other drugs in the viewfinder: nonsteroidal anti-inflammatory drugs (NSAIDs), due to their renal toxicity: “It is aggravated by dehydration, reports the doctor. People who, for various reasons, take this type of medicine – such as ibuprofen, over the counter – should pay particular attention to drinking enough water.
The warnings also concern, and more generally, all patients benefiting from long-term treatments, whatever they may be: “When you are dehydrated, the concentration of water-soluble drugs increases in the blood. ; their side effects are also increased. This is particularly the case for so-called “narrow therapeutic margin” drugs, for which the toxic concentrations are close to the effective concentrations. Therefore, small variations in dose or concentration may lead to a modification of the benefit/risk ratio.
Perspiration, an “air conditioning”
Preventing all of these risks can be summed up in two words: drink enough. “When temperatures are very high, a lot of water is lost through evaporation. ; perspiration is in a way our “air conditioning”. The water we consume being diverted to this function, it does not reach the kidneys. If we don’t take in enough water, we put kidney function at risk.”
How to be alerted by a lack of fluid intake? “If you urinate less frequently than usual and the urine produced is dark, you are not drinking enough.
And to know if you are dehydrated, just stick your tongue out in front of your ice cream or pinch yourself. “The skinfold test involves gently pinching the skin between the thumb and forefinger. If the skin immediately snaps back into place, everything is fine. If she keeps the mark and takes a few seconds to return to normal, this is a sign of dehydration. Another manifestation that does not deceive : the tongue, which then appears red and very dry.” A phenomenon known by the very trivial – but explicit – name of “roasted tongue”.