Magnesium hydroxide
Regulatory sources consulted
Approved indications
- Symptomatic treatment of occasional constipation and gastric hyperacidity in adults and adolescents aged 12 years or older.
Contraindications
Absolute
- Hypersensitivity, severe kidney impairment, or fluid and electrolyte imbalance.
- Symptoms of appendicitis or intestinal obstruction; undiagnosed gastrointestinal or rectal bleeding; ulcerative colitis, colostomy, diverticulitis, ileostomy, or chronic diarrhea.
Clinical warnings
- Major warning · Do not continue laxative use beyond 7 days or antacid use beyond 2 weeks without medical supervision. Kidney disease carries a hypermagnesemia risk. — CIMA AEMPS FT_34551
Drug interactions
- ModerateOther oral medicines
Mechanism: pH change, chelation, or binding may increase or reduce absorption of multiple medicines.
Recommendation: Separate magnesium hydroxide and other oral medicines by 2 to 3 hours; consult a doctor or pharmacist.
CIMA AEMPS FT_34551
Adverse events
Common (≥1%)
Diarrhea · Abdominal pain
Rare but serious
Hypermagnesemia
Pregnancy and lactation
During pregnancy and breastfeeding, avoid high doses or prolonged use; consult a professional.
Recent literature (PubMed)
Constipation is a common gastrointestinal problem in the elderly. Because of the limitations of life style modifications and the comorbidity, laxative use is also very common. Therefore, this study reviews the latest literature on the effect and safety of laxative in the elderly. A systematic review of randomized controlled trials investigating the effectiveness and safety of laxatives for constipation in elderly patients over 65 years old were performed using the following databases: PubMed, EMBASE, and the Cochrane Library. Twenty-three randomized controlled trials were included in this review. Among the selected studies, 9 studies compared laxative with placebo and 5 studies compared laxatives of the same type. Four studies compared different types of laxatives or compared combination agents. Five studies compared novel medications such as prucalopride, lubiprostone, and elobixibat with placebo. Psyllium, calcium polycarbophil, lactulose syrup, lactitol, polyethylene glycol, magnesium hydroxide, stimulant laxative with or without fiber, and other medications were more effective than placebo in elderly constipation patients in short-term. Generally, the frequency and severity of adverse effects of laxative were similar between the arms of studies. Bulk laxative, osmotic laxative, stimulant laxative with or without fiber, and other medications can be used in elderly patients in short-term within 3 months with reasonable safety. However, the quality of included studies was not high and most of studies was conducted in a small number of patients. Among these laxatives, polyethylene glycol seems to be safe and effective in long-term use of about 6 months in elderly patients.
Magnesium prevents vascular calcification in animals with CKD. In addition, lower serum magnesium is associated with higher risk of cardiovascular events in CKD. In a randomized, double-blinded, placebo-controlled trial, the authors investigated the effects of magnesium supplementation versus placebo on vascular calcification in patients with predialysis CKD. Despite significant increases in plasma magnesium among study participants who received magnesium compared with those who received placebo, magnesium supplementation did not slow the progression of vascular calcification in study participants. In addition, the findings showed a higher incidence of serious adverse events in the group treated with magnesium. Magnesium supplementation alone was not sufficient to delay progression of vascular calcification, and other therapeutic strategies might be necessary to reduce the risk of cardiovascular disease in CKD. Elevated levels of serum magnesium are associated with lower risk of cardiovascular events in patients with CKD. Magnesium also prevents vascular calcification in animal models of CKD. To investigate whether oral magnesium supplementation would slow the progression of vascular calcification in CKD, we conducted a randomized, double-blinded, placebo-controlled, parallel-group, clinical trial. We enrolled 148 subjects with an eGFR between 15 and 45 ml/min and randomly assigned them to receive oral magnesium hydroxide 15 mmol twice daily or matching placebo for 12 months. The primary end point was the between-groups difference in coronary artery calcification (CAC) score after 12 months adjusted for baseline CAC score, age, and diabetes mellitus. A total of 75 subjects received magnesium and 73 received placebo. Median eGFR was 25 ml/min at baseline, and median baseline CAC scores were 413 and 274 in the magnesium and placebo groups, respectively. Despite plasma magnesium increasing significantly during the trial in the magnesium group, the baseline-adjusted CAC
There has been a substantial increase in studies on functional constipation in children as new therapies are deployed. We aimed to provide an up-to-date, methodologically robust systematic review and meta-analysis on the efficacy and safety of pharmacological therapies for functional constipation in children. In this systematic review and meta-analysis, we searched PubMed, Medline, Embase, and the Cochrane library from inception to Feb 5, 2025. We included randomised controlled trials that involved children aged 0 years to younger than 18 years with functional constipation treated with pharmacological interventions compared with placebo, no treatment, or other interventions and with at least a 2-week follow-up period. Studies were excluded if there was no definition of functional constipation, children with organic causes for constipation or previous bowel surgery were included, children with faecal incontinence without the presence of constipation were included, or the aim of treatment was faecal disimpaction rather than maintenance therapy. Pairs of authors independently extracted summary data from published reports and critiqued studies. We assessed risk of bias with the Cochrane tool. Meta-analyses estimated risk ratios (RRs) or mean differences, and 95% CIs. Certainty of evidence was established with GRADE. Our main outcomes were treatment success (as defined by study authors), defecation frequency, and withdrawals due to adverse events. This study was registered on PROSPERO (CRD42022368719). Our search identified 4595 articles, of which 59 randomised controlled trials were included, representing 7045 participants with functional constipation. Interventions included polyethylene glycol (n=36 studies), lactulose (n=18), magnesium oxide or magnesium hydroxide (n=7), picosulfate (n=1), liquid paraffin (n=4), prucalopride (n=1), lubiprostone (n=2), linaclotide (n=3), plecanatide (n=1), enemas (n=2), and domperidone (n=1). Meta-analyses for treatment success showed