Drugs influencing acid base balance and bicarbonate concentration readings

ABSTRACT

Serum bicarbonate dosage is sensitive to pharmacological interferences. However, elevated bicarbonate concentration reflects chronic hypoventilation and has been proposed as a simple marker for screening patients with Obesity Hypoventilation Syndrome (OHS), a currently underdiagnosed multimorbid and high mortality disease. We provide a practical overview of the different drugs acting on the acid-base equilibrium to aid clinicians to interpret bicarbonate concentration readings. Little is known about the chronic impact of the usual doses of these drugs on serum bicarbonate concentration and further studies are needed. It is essential to take into account drugs that could interfere with this parameter to avoid misinterpretation of serum bicarbonate levels.

KEYWORDS:

• Bicarbonate
• drugs
• pharmacological interferences
• screening
• obesity hypoventilation syndrome

Financial and competing interests disclosure

The authors were supported by Fond de dotation Agir pour les maladies chroniques. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. Writing assistance was utilized in the production of this manuscript provided by Dr Alison Foote (Grenoble University Hospital, CHU de Grenoble) and funded by Agiradom.

Key issues

• Bicarbonate level is a simple marker to better screen for some diseases such as OHS.

• However, bicarbonate levels can be modified by various factors, particularly by pharmacological agents.

• This review lists the drugs that can modify bicarbonate level according to the mechanism inducing these interferences: (i) decrease of bicarbonate by metabolic acidosis or respiratory alkalosis and (ii) increase in bicarbonate by metabolic alkalosis or respiratory acidosis.

• Little is known about the chronic impact of drugs on serum bicarbonate concentration and further studies are needed.

• Widely used medications such as paracetamol can modify bicarbonate level.

• Patients suffering from respiratory diseases such as OHS often have many comorbidities and associated polypharmacy that can modify the bicarbonate level.

• It is essential to take into account drugs that could interfere with this parameter so as to avoid misinterpretation of serum bicarbonate concentrations.

• This process should be extended to other biological parameters and pathologies. Indeed, it is essential to establish a patient’s medication profile so as to apprehend pharmacological interferences with biological parameters.

• This medication profile takes into account the combination of comorbidities that often coexist with a respiratory pathology.