Bictegravir
Severe
Database
Clinical effect not specified
Source: DDInter
Drug reference
Calcium Carbonate
Calcium salt (antacid / calcium supplement / phosphate binder) · Antacid, Calcium Supplement, Treatment of Hypocalcemia, Hyperphosphatemia Management, Osteoporosis Prophylaxis
Also known as Precipitated Chalk, Oyster Shell Calcium, Calcite
START
Antacid 0.5–1.5 g PRN; supplement ~1–1.5 g elemental Ca/day with food (divided)
TYPICAL MAX
Elemental calcium ≤~2–2.5 g/day total; antacid short-term only
STOP IF
Hypercalcaemia/milk-alkali syndrome, recurrent calcium stones
WATCH
Serum calcium (esp. with vitamin D/CKD), constipation, separate from interacting drugs
CDSCO approvedOTCJan AushadhiNPPA price-controlledATC A02AC01
KDIGO 2024 + manufacturer label
- ONSET
- 5min · antacid onset (~5 min)
- PEAK
- 30min · acid neutralisation
- t½
- 1h · buffering (illustrative)
- DURATION
- 1h · antacid effect
EXCRETION
Faecal unabsorbed; absorbed calcium renal
route + CYP
INTERACTIONS
10 major
SEVERE in our sources
PREGNANCY
Compatible — used for heartburn and calcium supplementation; avoid excessive doses (milk-alkali)
FDA category + note
Top interactionssee all 12 →
- BictegravirSevereDatabaseDDInter
- DolutegravirSevereDatabaseDDInter
- ErdafitinibSevereDatabaseDDInter
- LevothyroxineSevereDatabaseKimi deep-research + Cla
Available in India
0 branded formulations and 20 fixed-dose combinations. Look up specific brands in the Drugs workspace.
Jan Aushadhi — generic available at GoI pharmacies
Mechanism
Neutralises gastric acid (acid-buffering) liberating CO2; provides elemental calcium (40% of weight) for supplementation; binds dietary phosphate in the gut (CKD).
Indications
Dyspepsia/heartburn (antacid)Calcium supplementation (osteoporosis prevention/treatment, hypocalcaemia)Hyperphosphataemia in chronic kidney disease (phosphate binder)
Dosing
- Adult
- Antacid: 0.5–1.5 g PRN (max ~7.5 g/day short-term). Supplement: 1–1.5 g elemental calcium/day in divided doses with food. Phosphate binder: 0.5–1.5 g elemental with meals, titrate to phosphate.
- Pediatric
- Supplement per age/requirement (specialist).
- Renal adjustment
- In CKD as phosphate binder — titrate to phosphate; risk of hypercalcaemia/vascular calcification (limit elemental calcium).
- Hepatic adjustment
- No specific adjustment.
- Geriatric
- Monitor for constipation/hypercalcaemia.
- Max dose
- Elemental calcium generally ≤2–2.5 g/day total (diet + supplement); antacid short-term
Pharmacokinetics
Onset
Antacid within minutes
Peak effect
Acid neutralisation rapid; supplementation chronic
Duration
Antacid ~20–60 min (longer with food)
Half-life
Not applicable (ion)
Bioavailability
~25–30% calcium absorbed (acid- and food-dependent)
Protein binding
Calcium ~40% protein-bound in plasma
Metabolism
Not metabolised
Excretion
Faecal (unabsorbed) and renal (absorbed calcium)
Contraindications
- Hypercalcaemia / conditions predisposing to it
- Severe hypophosphataemia
- Calcium nephrolithiasis (relative)
- Hypersensitivity
Side effects
Common
ConstipationBloating/flatulence (CO2), belchingAcid rebound (high-dose antacid)Dyspepsia
Serious
- Hypercalcaemia / milk-alkali syndrome (high-dose with vitamin D/alkali)
- Nephrolithiasis/nephrocalcinosis
- Vascular calcification (CKD, excessive elemental calcium)
- Rebound hyperacidity
Pregnancy & lactation
Pregnancy
Compatible — used for heartburn and calcium supplementation; avoid excessive doses (milk-alkali)
Lactation
Compatible at recommended doses
Drug interactions
Dolutegravir
Severe
Database
Clinical effect not specified
Source: DDInter
Erdafitinib
Severe
Database
Clinical effect not specified
Source: DDInter
Levothyroxine
Severe
Database
Reduced levothyroxine absorption → hypothyroidism
Separate by ≥4 h; monitor TSH
Source: Kimi deep-research + Cla
Patiromer
Severe
Database
Clinical effect not specified
Source: DDInter
Raltegravir
Severe
Database
Clinical effect not specified
Source: DDInter
Selpercatinib
Severe
Database
Drug interaction classified as: absorption
Source: DDInter
Tetracyclines
Severe
Database
Chelation → markedly reduced antibiotic absorption/efficacy
Separate by ≥2–4 h
Source: Kimi deep-research + Cla
Thiazide Diuretics + Vitamin D
Severe
Database
Reduced calcium excretion → hypercalcaemia/milk-alkali
Monitor serum calcium
Source: Kimi deep-research + Cla
Tolevamer
Severe
Database
Clinical effect not specified
Source: DDInter
Ciprofloxacin
Moderate
Textbook-cited
Therapeutic failure of the antibiotic.
Stagger administration by 2-3 hours
Source: KDT 7e · p949
Doxycycline
Moderate
Textbook-cited
Therapeutic failure of the antibiotic.
Stagger administration by 2-3 hours
Source: KDT 7e · p949
Related guidelines
Chronic kidney disease — assessment and management
KDIGO · Nephrology · 2024
Chronic kidney disease — assessment and management
NICE · Nephrology · 2021
Cardiovascular disease prevention
ESC · Cardiology · 2021
Primary prevention of cardiovascular disease
AHA · Cardiology · 2019
Chronic kidney disease — mineral and bone disorder
KDIGO · Nephrology · 2017
Ask House about Calcium Carbonate
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e, Katzung, BNF·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19