Osmotic laxative / antacid
Magnesium hydroxide
Brand names: Milk of Magnesia
Adult dose
Dose: Laxative: 30–45mL at night. Antacid: 5–10mL PRN
Route: PO
Frequency: PRN-OD
Clinical pearls
- Mild constipation; symptomatic dyspepsia
Contraindications
- Severe renal impairment
- Hypermagnesaemia
- Bowel obstruction
Side effects
- Diarrhoea
- Hypermagnesaemia
- Abdominal cramps
Interactions
- Tetracyclines/quinolones
- Levothyroxine
- Iron
Reference: BNF; https://bnf.nice.org.uk/drugs/magnesium-hydroxide/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Lower Gastrointestinal Bleed · BSG 2019; NICE NG141
- Variceal Upper GI Bleed · BSG 2015; Baveno VII (2022)
- Spontaneous Bacterial Peritonitis (SBP) · BSG / EASL 2018
- Hepatorenal Syndrome · EASL 2018; ICA 2015
- Hepatic Encephalopathy · EASL 2014; West Haven criteria
- Clostridioides difficile Colitis · NICE NG199 (2021); IDSA/SHEA 2021