Association between the Long-Term Use of Over-the-Counter Laxative and Biochemical and Inflammatory Markers in Older Adults: Comparative Cross-Sectional Study

Abstract

Background: Constipation is a common issue among the geriatric population that often leads to the chronic use of over-the-counter (OTC) laxatives. Osmotic laxatives, such as lactulose and polyethylene glycol (PEG), act by drawing water into the colon, causing loose stools, while stimulants like senna and bisacodyl irritate the colon, causing accelerated motility. The long-term abuse of laxatives could cause dehydration and electrolyte imbalance.

Aims: To evaluate the association between the long-term use of different OTC laxatives lactulose, polyethylene glycol (PEG), and Agiolax (psyllium senna) and biochemical and inflammatory parameters in geriatric patients.

Patients and Methods: This comparative cross-sectional observational study included 150 geriatric patients (aged ≥65-year-old) who had been using OTC laxatives (lactulose, PEG and Agiolax) for long-term titrated to response. There were 50 patients in each group, alongside 50 person, aged matched with history of chronic constipation without using laxatives as control group. Data and blood samples were collected from both the outpatient and emergency departments of Imam Al-Sadeq Teaching Hospital in Hilla province. The measured parameters included serum electrolytes (Na⁺, K⁺, Cl^-), and blood urea with serum creatinine in addition to inflammatory markers include ESR, C-reactive protein.

Results:

Administration of lactulose and PEG associated with significant elevation of serum sodium (P<0.001), lactulose associated with significant hypochloremia (p<0.001) although both PEG and Agiolax showed statistically significant (p< 0.01) but clinically insignificant reduction in serum chloride. Both lactulose and Agiolax administration associated with significant hypokalemia (p<0.001) and significant (p<0.001) elevation in blood urea and serum creatinine. Lactulose shows statistically significant elevation in ESR (p<0.001) when compare to control group while Agiolax shows statistically significant reduction (p<0.001) however this result was clinically insignificant as it remains within the normal value. 70% of the patients on lactulose and 52% of those on PEEG had positive neurological symptom associated with electrolytes disturbance while 46% of them on lactulose and 58% of those on Agiolax had positive cardiovascular presentation.