Aluminum Hydroxide
Also known as: Amphojel · AlternaGEL · Dialume · Maalox (when combined with Magnesium) · Aluminium hydroxide · Al(OH)3
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Hyperphosphatemia | 30-100 mg/kg/day | PO | with meals | — | 🌎 NA |
| Hyperphosphatemia | 30-90 mg/kg/day | PO | prior to meals | — | 🌎 NA |
| Hyperphosphatemia | 15-45 mg/kg | PO | q12h | — | 🌎 NA |
| Adjunctive therapy for gastric ulcers | 2-10 mL | PO | q2-4h | — | 🌎 NA |
| Adjunctive therapy for gastric ulcers | ½-1 tablet or strength | PO | q6h | — | 🌎 NA |
- Hyperphosphatemia: Aluminum hydroxide gel, dried powder. The dried powder is virtually tasteless and accepted readily by most cats when mixed with canned food.
- Adjunctive therapy for gastric ulcers: Aluminum hydroxide suspension or aluminum hydroxide/magnesium hydroxide suspension
- Adjunctive therapy for gastric ulcers: Aluminum hydroxide tablets
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Hyperphosphatemia | Initially at 30-90 mg/kg per day | PO | divided with meals | — | 🌎 NA |
| Hyperphosphatemia | 15-45 mg/kg | PO | q12h | — | 🌎 NA |
| As an antacid | ¼ tablet | PO | q6h | — | 🌎 NA |
- Hyperphosphatemia: Dosage must be individualized. Capsules or suspension are preferred as they are more easily mixed with food and dispersed throughout ingesta.
- As an antacid: Aluminum hydroxide tablets
Small Mammals
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| General | 1 mL/animal | PO | as needed | — | 🌎 NA |
| General | 0.5-1 mL/animal | PO | as needed | — | 🌎 NA |
- General: Chinchillas; Aluminum hydroxide gel
- General: Guinea pigs
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Adjunctive gastroduodenal ulcer therapy in foals | 15 mL (total dose) | PO | 4 times a day | — | 🌎 NA |
- Adjunctive gastroduodenal ulcer therapy in foals: Aluminum/magnesium hydroxide suspension
Cattle
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| As an antacid | 30 grams/animal | PO | as needed | — | 🌎 NA |
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Aluminum hydroxide is an orally administered compound primarily used in veterinary medicine as an enteric phosphate binder to manage hyperphosphatemia in patients with chronic kidney disease (CKD).
- It is also utilized as a gastric antacid to treat or prevent gastrointestinal ulcers.
-
Clinical Pearl: While human liquid antacids (like mint-flavored suspensions) are available over-the-counter, they are often highly unpalatable to dogs and cats. Compounded dried powders are virtually tasteless and much easier to administer when mixed with canned food.
Mechanism of action
- Phosphate Binding: In the gastrointestinal tract, aluminum binds to dietary phosphate → forms insoluble aluminum phosphate → excreted in the feces. This prevents the systemic absorption of phosphorus, thereby lowering serum phosphorus levels.
- Antacid: Neutralizes gastric hydrochloric acid → increases gastric pH → reduces pepsin activity, providing a protective effect on the gastric mucosa.
Safety & warnings
Contraindications
- Use with caution in patients with delayed gastric emptying or severe constipation
- Use with caution in patients with severe renal failure due to risk of aluminum accumulation
Adverse effects
- Constipation
- Aluminum toxicity (neuromuscular weakness, microcytosis) with chronic use or severe renal impairment
- Hypophosphatemia (if over-supplemented)
Precautions
Use with caution in patients with renal failure due to the risk of aluminum accumulation and toxicity. Monitor for neuromuscular signs and progressive decreases in mean cell volume (MCV) or microcytosis. Human liquid suspensions are often flavored (e.g., mint) and poorly accepted by animals.
Drug interactions
Decreased absorption; separate oral doses by two hours
Decreased absorption; separate oral doses by two hours
Decreased absorption; separate oral doses by two hours
Decreased absorption; separate oral doses by two hours
Decreased absorption; separate oral doses by two hours
Monitoring
- Serum phosphorus (after a 12-hour fast), initially at 10-14 day intervals; once 'stable', at 4-6 week intervals
- Neuromuscular effects (signs of aluminum toxicity)
- Progressive decreases in mean cell volume (MCV) and microcytosis
Pharmacokinetics
Absorption
Minimal systemic absorption. Acts locally in the gastrointestinal tract.
Distribution
Locally distributed in the GI tract; any absorbed aluminum distributes to bone, liver, and brain.
Metabolism
Not metabolized.
Elimination
Excreted primarily in the feces as insoluble aluminum phosphate. Any systemically absorbed aluminum is excreted by the kidneys.
Overdose
Chronic overdosage or accumulation in patients with severe renal failure can lead to aluminum toxicity.
- Signs of toxicity include neuromuscular effects (weakness, stumbling, difficulty walking) and hematological changes (progressive decreases in mean cell volume [MCV] and microcytosis).
Available products
Formulations
- Capsules
- Tablets
- Suspension/Liquid
- Dried Powder
Veterinary
- None
Human-labeled
- Aluminum Hydroxide Oral Capsules: 500 mg (Dialume®)
- Aluminum Hydroxide Oral Tablets: 600 mg (Amphojel®)
- Aluminum Hydroxide Concentrated Gel Suspension/Liquid: 320 mg/5 mL, 450 mg/5 mL, 675 mg/5 mL, 600 mg/5 mL (AlternaGEL®)
- Aluminum Hydroxide Gel, Dried Powder, USP (Bulk powder available from compounding pharmacies)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature in tight containers. Protect liquid formulations from freezing.
Client information
- Oral aluminum hydroxide products are available without a prescription (OTC), but should always be used under the supervision of a veterinarian.
- Administration: Give either just before feeding or mixed directly into the food. This is essential for the drug to bind to the phosphorus in the diet.
- Formulations: Bulk powders, tablets, or capsules (which may be compounded) are generally much easier to administer than human liquids or suspensions, which often have mint flavoring that pets dislike.
-
Warning: Report any unusual neuromuscular signs such as weakness, difficulty walking, or stumbling to your veterinarian immediately, as this could indicate aluminum toxicity.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.