Formulary
Sodium phenylbutyrate: Indications, Dosing, Side Effects and Interactions
Sodium phenylbutyrate clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 3 min read
Sodium phenylbutyrate: Indications, Dosing, Side Effects and Interactions
Sodium phenylbutyrate clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Long-term treatment of urea cycle disorders (as adjunctive therapy in all patients with neonatal-onset disease and in those with late-onset disease who have a history of hyperammonaemic encephalopathy) (under expert supervision)**
- **Adult** (By Mouth): 9.9-13 g/m 2 daily in divided doses, with meals; maximum 20 g per day.
**Acute hyperammonaemia due to urea cycle disorders (specialist use only) for sodium phenylbutyrate**
- **Neonate** (By intravenous infusion): Initially 250 mg/kg, to be administered over 90 minutes, followed by 10 mg/kg/hour, adjusted according to response.
- **Child** (By intravenous infusion): Initially 250 mg/kg, to be administered over 90 minutes, followed by 10 mg/kg/hour, adjusted according to response.
**Maintenance treatment of hyperammonaemia due to urea cycle disorders (specialist use only) for sodium phenylbutyrate**
- **Neonate** (By mouth): Up to 250 mg/kg daily in 3-4 divided doses, with feeds.
- **Child (body-weight up to 20 kg)** (By mouth): Up to 250 mg/kg daily in 3-4 divided doses, with feeds or meals.
- **Child (body-weight 20 kg and above)** (By mouth): 5 g/m2 daily in 3-4 divided doses, with meals; maximum 12 g per day.
Cautions
Conditions involving sodium retention with oedema (preparations contain significant amounts of sodium); congestive heart failure (preparations contain significant amounts of sodium)
Side effects
Common or very common Abdominal pain; anaemia; appetite decreased; constipation; depression; headache; irritability; leucocytosis; leucopenia; menstrual cycle irregularities; metabolic acidosis; metabolic alkalosis; nausea; oedema; renal tubular acidosis; skin reactions; syncope; taste altered; thrombocytopenia; thrombocytosis; vomiting; weight increased Uncommon Anorectal haemorrhage; aplastic anaemia; arrhythmia; gastrointestinal disorders; pancreatitis
Interactions
**Other interactions (2):**
- There have been published reports of hyperammonaemia being induced by haloperidol and by valproate.
- Corticosteroids may cause the breakdown of body protein and thus increase plasma ammonia levels.
Pregnancy
Avoid-toxicity in animal studies.
Breast feeding
Manufacturer advises avoid-no information available.
Hepatic impairment
Manufacturer advises caution.
Renal impairment
Manufacturer advises use with caution (preparations contain significant amounts of sodium).
Medicinal forms
Capsule,Tablet,Solution,Granules
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
Inside MedNext for this topic
- 411 MedNext-authored chapters
- 80,000+ MCQ bank
- 15 study modes
- Growing visual cheat sheets
Study modes
- Notes
- MCQ
- Audio
- Video
- Visual
- 3D Anatomy
- Trace
- Flashcards
- Mnemonics
- Image Bank
- Clinical
- Microscopy
- Audio QBank
- Cadaver
- Book Match
Continue reading
Subject HubPharmacology Hub
All pharmacology resources in one place.
Drug SchedulesIndian Drug Schedules
Schedule H, H1, X and G classifications.
FormularyBrowse all drugs
Search 1,850+ drug profiles.
Study Sodium phenylbutyrate in the MedNext app
Challenge yourself with targeted pharmacology MCQs on this drug class. Every explanation links back to the chapter that teaches the concept.
Start drug challengeExplore the full formulary

