Why is it important to measure blood sodium in those receiving psychotropic drugs?

Question: My mother is 79 years old and is in a nursing home. Three months ago she decompensated, so they took her to the hospital. A doctor detected that she was lacking sodium in her blood due to an antidepressant they had given her and thanks to that she recovered. (JAQ, Bahía Blanca)

It is not a new problem in people who take psychotropic drugs, although in medical practice many times it is not given due attentiongoing unnoticed even by the psychiatrist.

This is hyponatremia (hypo = little; natremia = amount of sodium in the blood) which was first described in 1974 in patients receiving amitriptyline, an effective antidepressant widely used at that time.

Sodium performs key functions in the body: helps maintain blood pressure within normal values, It is essential in the normal activity of muscles and nerves, while regulating the balance of fluids in the body.

The normal level of sodium in the blood ranges between 135 and 145 milliequivalents per liter (mEq/L) and Hyponatremia occurs when sodium is below 135 mEq/L.

The consequences of hyponatremia will depend on how much sodium has decreased (the greater the decrease, the greater the symptoms) and the speed with which this occurs.

It is relatively common in patients receiving different psychotropic drugs and It is present from the first weeks of treatment.

This happens especially with antidepressants, although it can also happen – less frequently – with mood stabilizers, antipsychotics and antiepilepticsamong others.

It is worth noting that other types of medications (diuretics, cytostatics, analgesics) can also have the same consequence.

Some characteristics to highlight are that occurs more frequently in people over 60 years of agemore in women than in men (although not exclusively) and in those who are institutionalized.

In young people it has been related to serious situationssometimes fatal, in those who use ecstasy as a recreational drug.

One of the reasons why the risk of sodium depletion increases with age is because the progressive decline in the functioning of various organs that impact the absorption, distribution, metabolism and excretion of medications.

And even more so if heart, kidney, liver or low weight problems coexist.

Because hyponatremia can cause disorientation, confusion, lack of energy, depression, restlessness, irritability, or restlessness, Many times these symptoms lead one to think that the patient is worse.so higher doses of psychotropic drugs are indicated, which can lead to a risky vicious circle.

Decreased sodium concentration in the blood appears in any disorder that causes water to accumulate in greater quantities in the bloodso that the sodium is diluted.

Therefore, those who should be especially careful are when there is an excess of sugar level in the blood (diabetes), any disease that causes fluid retention or when a lot of liquid is ingested (be it beer, tea, mate or even water) or when there is an exaggerated secretion of the hormone vasopressin.

It is important that all patients over 60 years of age who receive psychotropic drugs Always keep in mind to measure your blood sodium levelwhich is done with a simple blood test.