Sodium citrate
Trisodium citrate
Also known as: Micolette · Micralax · Relaxit · Citric acid trisodium salt
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 |
|---|---|---|---|---|---|
| Constipation / Lower GI tract preparation | 1 enema inserted per rectum to full length of nozzle | Rectal | As needed | Single dose | 🌍 EU |
- Constipation / Lower GI tract preparation: Used for all indications (constipation, proctoscopy/radiography prep)
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Constipation / Lower GI tract preparation | 1 enema inserted per rectum to full length of nozzle | Rectal | As needed | Single dose | 🌍 EU |
- Constipation / Lower GI tract preparation: Used for all indications (constipation, proctoscopy/radiography prep)
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Sodium citrate is an osmotic laxative typically formulated as a micro-enema in combination with a stool softener (such as sodium alkylsulphoacetate, sodium lauryl sulphoacetate, or sodium lauryl sulphate). It is primarily used as a low-volume enema to treat constipation and to prepare the lower gastrointestinal tract for procedures like proctoscopy and radiography.
Clinical Warning: Not recommended for use in cases with inflammatory bowel disease (IBD).
Clinical Pearl: The monograph text lists "450 ml sodium citrate" per micro-enema, which is likely a typographical error in the source material for 450 mg, as these are typically 5 ml low-volume micro-enemas.
Mechanism of action
Acts as an osmotic laxative → causes water to be retained within the lumen of the GI tract. The addition of a stool softener lowers surface tension → augments the laxative action by allowing water to penetrate and soften the feces.
Safety & warnings
Contraindications
- Inflammatory bowel disease (IBD)
Adverse effects
- Water and electrolyte disturbances (uncommon)
Precautions
Normal safety and handling precautions should be observed. Use with caution in dehydrated patients or those with severe electrolyte imbalances.
Monitoring
- Fecal output and consistency
- Hydration status
- Electrolyte levels (if used repeatedly)
Pharmacokinetics
Absorption
Minimal systemic absorption; acts locally in the lower gastrointestinal tract.
Distribution
Confined primarily to the rectal and colonic lumen.
Metabolism
Not significantly metabolized.
Elimination
Excreted in feces.
Overdose
Excessive or repeated use may lead to severe water and electrolyte disturbances, including dehydration and hypernatremia. Treatment is supportive, focusing on rehydration and electrolyte correction.
Available products
Formulations
- Rectal micro-enema: 450 ml [sic] sodium citrate with 45 mg sodium alkylsulphoacetate (Micralax)
- Rectal micro-enema: 450 ml [sic] sodium citrate with 45 mg sodium lauryl sulphoacetate (Micolette)
- Rectal micro-enema: 450 ml [sic] sodium citrate with 75 mg sodium lauryl sulphate (Relaxit)
Human-labeled
- Micolette micro-enema
- Micralax micro-enema
- Relaxit micro-enema
Regulatory status
Typically authorized as human OTC products used off-label in veterinary medicine under the cascade.
Pharmacy (P) medicine for humans, used off-label in animals.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature in a dry place. Protect from excessive heat.
Client information
Administration: This medication is given rectally as an enema. Insert the nozzle to its full length as directed by your veterinarian.
Hydration: Ensure your pet has access to plenty of fresh drinking water, as enemas can cause fluid loss.
Warning: Do not use if your pet has been diagnosed with inflammatory bowel disease. Contact your vet if your pet shows signs of weakness, vomiting, or if no stool is produced after administration.
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.