Heavy Metal Index
Ask the IndexAboutIndex Pro

Hypermagnesemia in a psychiatric hospital

Cite this pageVersion history

Summary

Retrospective cohort study of all patients admitted to Ainohanazono Hospital (Japan) between January 2020 and December 2023 who had at least one blood test (n = 1,120). Among these, 532 (48%) were prescribed magnesium oxide (MgO) as a laxative for constipation. The risk of developing hypermagnesemia was 2.76 times higher for patients prescribed MgO than for those not prescribed it. Risk factors for hypermagnesemia included MgO dose, elevated serum creatinine, and female biological sex. The study identifies a vulnerable clinical population for iatrogenic hypermagnesemia from oral magnesium supplementation.

Key numbers

  • Total patients with at least one blood test: 1,120 (p. 3 methods)
  • Prescribed MgO: 532 (48%) (p. 1 abstract)
  • Hazard ratio for hypermagnesemia, MgO vs. no MgO: 2.76 (p. 1 abstract)
  • Hazard ratio for daily MgO dose: HR 2.66 (p. 1 abstract)
  • Hazard ratio for serum creatinine: HR 1.75 (p. 1 abstract)
  • Hazard ratio for female biological sex: HR 1.44 (p. 1 abstract)
  • Average MgO dose: 1,000 mg (SD 480 mg) (p. 3 Wald’s test reference)
  • Among 1,120 patients with normal blood Mg at initial test: 532 (48%) received MgO prescriptions during observation; 588 (52%) did not (p. 4 Kaplan-Meier reference)
  • Antipsychotic and anticholinergic drug dosages modestly increased prescribed MgO dose (OR 1.12 and OR 1.06 respectively) (p. 1 abstract)
  • Long-term treatment duration (OR 0.91) and blood urea nitrogen (OR 0.95) were associated with decreased MgO dose (p. 1 abstract)

Evidence Fitness

Reconstructable dataset. Retrospective cohort; n = 1,120; single hospital in Japan; 2020 to 2023. The study identifies the hazard ratio for MgO-related hypermagnesemia and clinical risk factors within a psychiatric inpatient population. The finding of impaired renal function (elevated creatinine) as an independent risk factor is clinically actionable and consistent with the known mechanism of magnesium excretion. Results are specific to a population with concurrent antipsychotic and anticholinergic drug use, which affects gut motility and therefore both constipation prevalence and MgO dosing.

Methods (brief)

Retrospective chart review. Hypermagnesemia defined by blood test result (threshold value not specified in abstract). Time-to-event analysis using Kaplan-Meier method and Wald’s test for covariate evaluation. Hazard ratios reported from survival analysis. Odds ratios for determinants of MgO dosage from logistic regression (inferred from OR language in abstract).

Implications

  • Courses: illustrates that oral magnesium supplementation in clinical contexts (not dietary) carries a 2.76-fold hypermagnesemia risk; impaired renal function is the primary amplifier, consistent with the physiological role of the kidney in magnesium regulation; this is the mechanistic basis for the clinical recommendation to monitor serum magnesium in long-term MgO users with renal impairment.
  • App: no contamination_profile implication; magnesium as a laxative is pharmaceutical, not dietary.
  • Microbiome: no direct connection.

Provenance notes

Open access (cc-by). Retrieved from PMC Open Access S3 (PMC12266991). SHA256 verified against MANIFEST.csv.

Update history

No substantive edit history is available in this build. The full commit record is available in git.

Referenced by