Bisphosphonates
Moderate
Database
Chelation
Separate widely
Source: Kimi deep-research + Cla
Drug reference
magnesium trisilicate
Antacid (magnesium silicate, non-systemic) · Antacid
START
1–2 tablets chewed 3–4 times daily PRN
TYPICAL MAX
~2 g/day
STOP IF
Severe diarrhoea or symptomatic hypermagnesaemia
WATCH
Renal function (avoid in severe impairment); chronic high-dose use
CDSCO approvedATC A02AA20
KDIGO 2024 + manufacturer label
- ONSET
- 6min · neutralise
- PEAK
- 30min · local peak
- t½
- 36s · not absorbed
- DURATION
- 2h · gastric empty
EXCRETION
Faecal (silica); absorbed Mg renal
route + CYP
INTERACTIONS
—
none in our sources
PREGNANCY
Acceptable short-term use at recommended doses.
FDA category + note
Mechanism
Reacts slowly with gastric acid to form magnesium chloride and silicon dioxide gel, neutralising acid and coating the mucosa; magnesium provides a mild osmotic laxative effect.
Indications
Dyspepsia / heartburnPeptic ulcer symptom relief (adjunct)Reflux symptoms
Dosing
- Adult
- 1–2 tablets (250–500 mg) chewed 3–4 times daily and at bedtime as needed.
- Pediatric
- Limited use; per paediatric formulation.
- Renal adjustment
- Avoid in severe renal impairment (hypermagnesaemia).
- Hepatic adjustment
- No adjustment.
- Geriatric
- Caution; renal-decline accumulation.
- Max dose
- ~2 g/day (typical chronic intake)
Pharmacokinetics
Onset
Neutralisation within minutes
Peak effect
Local within minutes
Duration
~1–3 h (gastric emptying)
Half-life
Not applicable (poor absorption; Mg renal clearance if absorbed)
Bioavailability
Low (poor magnesium/silica absorption)
Protein binding
Not applicable
Metabolism
Not metabolised
Excretion
Faecal (silica); absorbed Mg renally
Contraindications
- Severe renal impairment (magnesium accumulation)
- Hypersensitivity
Side effects
Common
Diarrhoea (osmotic)BelchingFlatulenceHypermagnesaemia (renal impairment)
Serious
- Hypermagnesaemia in renal failure (weakness, hyporeflexia, arrhythmia)
- Silica renal stones (chronic high-dose)
- Severe diarrhoea
Pregnancy & lactation
Pregnancy
Acceptable short-term use at recommended doses.
Lactation
Compatible (poor systemic absorption).
Drug interactions
Drugs Requiring Acid For Absorption
Moderate
Database
Reduced gastric acidity
Separate dosing or alternative antacid
Source: Kimi deep-research + Cla
Iron Salts
Moderate
Database
Reduced iron absorption
Separate dosing
Source: Kimi deep-research + Cla
Levothyroxine
Moderate
Database
Reduced thyroxine absorption
Separate by ≥4 h
Source: Kimi deep-research + Cla
Nitrofurantoin
Moderate
Database
Decreased efficacy of nitrofurantoin, potentially leading to treatment failure for urinary tract infections.
Separate administration by at least 2-3 hours. Consider alternative antacids if frequent use is required.
Tetracyclines
Moderate
Database
Cation chelation
Separate by ≥2–4 h
Source: Kimi deep-research + Cla
Related guidelines
Gastric premalignant conditions
ACG · Gastroenterology · 2025
Preventive care in inflammatory bowel disease
ACG · Gastroenterology · 2025
Gastro-oesophageal reflux disease
ISG · Gastroenterology · 2022
Helicobacter pylori infection
ICMR · Gastroenterology · 2021
Systemic lupus erythematosus
EULAR · Rheumatology · 2023
Ask House about magnesium trisilicate
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e·Verified: 2026-05-20 · House clinical team·Cockpit curated: 2026-05-20