Generic Name: Carglumic Acid
Class: Ammonia Detoxicants
Chemical Name: N-carbamoyl-l-glutamic acid
Molecular Formula: C6H10N2O5
CAS Number: 1188-38-1
Uses for Carbaglu
Adjunctive therapy for the treatment of acute hyperammonemia in patients with deficiency of N-acetylglutamate synthase (NAGS), a hepatic enzyme required for activation of the first enzyme in the urea cycle;1 3 5 designated an orphan drug by FDA for treatment of NAGS deficiency.6
Treat any episode of acute symptomatic hyperammonemia as a life-threatening emergency; prompt use of all necessary therapies (e.g., dialysis [preferably hemodialysis], caloric supplementation, protein restriction, sodium phenylacetate and sodium benzoate, IV arginine) to reduce ammonia concentrations is essential.1 3 4 5 8 9
Maintenance therapy for chronic hyperammonemia in patients with NAGS deficiency.1 3 4 5 During maintenance therapy, protein restriction and other concomitant therapies used to reduce ammonia concentrations may be reduced or discontinued.1 3 4
Carbaglu Dosage and Administration
Distributed to hospital pharmacies via Accredo wholesale distribution services.12
Administer orally in 2–4 divided doses daily immediately before meals or feedings.1
Dispersion for Adult Use
Dispersion for Pediatric Use
Using oral syringe, withdraw appropriate dose and administer immediately; to ensure full dose is administered, refill the oral syringe with 1–2 mL of water and administer immediately.1 10 Discard any unused portion of dispersion.1 10
100–250 mg/kg daily.1 Round total daily dosage to nearest 100 mg (i.e., half-tablet dosage strength) and administer in 2–4 divided doses.1 12 Adjust dosage based on symptoms and plasma ammonia concentrations.1
Based on limited data, maintenance dosage usually <100 mg/kg daily.1 Round total daily dosage to nearest 100 mg (i.e., half-tablet dosage strength) and administer in 2–4 divided doses.1 12 Adjust dosage to maintain a target normal plasma ammonia concentration.1 3
No special population dosage recommendations at this time.1
Cautions for Carbaglu
Manufacturer states none known.1
Emergency Treatment of Hyperammonemia
Risk of rapid brain damage or death if acute symptomatic hyperammonemia is left uncontrolled; treat as a life-threatening emergency.1 3 4 5 8 9 Prompt use of all necessary therapies to reduce serum ammonia concentrations (e.g., dialysis [preferably hemodialysis]) is essential.1 3 4 5 8 9 Caloric supplementation recommended to reverse catabolism and reduce protein turnover; complete restriction of dietary protein recommended for 24–48 hours.1 4 5 8 9 (See Hyperammonemia under Uses.)
Manage hyperammonemia due to inborn errors of metabolism in coordination with medical personnel familiar with such conditions; usually requires health-care facilities able to provide multidisciplinary treatment (e.g., hemodialysis, nutritional management, medical support).1 4 5 8 9
Closely monitor plasma ammonia concentrations, neurologic status, laboratory tests, and clinical response during treatment.1
Protein restriction and hypercaloric intake recommended to block ammonia-generating catabolic pathways during acute hyperammonemic episodes.1 4 5 8 9 Dietary protein intake may be increased when plasma ammonia concentrations normalize, with goal of unrestricted protein intake.1 3 4
Safety and efficacy not established.1
Common Adverse Effects
Infections (e.g., tonsilitis, ear infection, nasopharyngitis), vomiting, abdominal pain, diarrhea, fever, anemia, headache.1
Interactions for Carbaglu
No formal drug interaction studies to date.1
Ammonia concentrations decrease within 24 hours.1
Distributed into milk in rats; not known whether distributed into human milk.1
Part of administered dose may be metabolized by intestinal bacteria to form carbon dioxide.1
Excreted in feces (≤60%) and in urine (9%) as unchanged drug and through the lungs as carbon dioxide.1
Median terminal half-life: 5.6 hours.1
Unopened container: 2–8°C.1
Normal neurologic development may be possible if therapy is started early (before irreversible brain damage).2
Advice to Patients
Importance of instructing patients and/or their caregivers regarding proper dosage, preparation, and administration.1 10 Importance of not crushing tablets or swallowing tablets whole.1 Importance of dispersing each tablet in ≥2.5 mL of water and immediately swallowing or administering mixture.1
Importance of informing patients and/or their caregivers that treatment is continuous and lifelong for patients with NAGS deficiency.1
Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.1
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal supplements, as well as any concomitant illnesses.1
Importance of informing patients and/or their caregivers of other important precautionary information.1 (See Cautions.)
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
Distribution of carglumic acid is restricted.11 (See Restricted Distribution under Dosage and Administration.)
Tablets, dispersible, scored
AHFS DI Essentials. © Copyright 2017, Selected Revisions May 1, 2013. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.
1. Accredo Health Group, Inc. Carbaglu (carglumic acid) tablets prescribing information. Memphis, TN; 2012 May.
2. US Food and Drug Administration. Center for Drug Evaluation and Research. Application number 22-562: Medical review(s). From FDA website.
3. Häberle J. Role of carglumic acid in the treatment of acute hyperammonemia due to N-acetylglutamate synthase deficiency. Ther Clin Risk Manag. 2011; 7:327-32. [PubMed 21941437]
4. Häberle J, Boddaert N, Burlina A et al. Suggested guidelines for the diagnosis and management of urea cycle disorders. Orphanet J Rare Dis. 2012; 7:32. [PubMed 22642880]
5. Lanpher BC, Gropman A, Chapman KA et al. Urea cycle disorders overview. In: Pagon RA, Bird TD, Dolan CR et al., eds. GeneReviews [Internet]. Seattle: University of Washington, Seattle; 2011 Sep 1.
6. Food and Drug Administration. FDA Application: Search Orphan Drug Designations and Approvals. Rockville, MD. From FDA website. Accessed 2012 Nov 27.
7. Summar M, Tuchman M. Proceedings of a consensus conference for the management of patients with urea cycle disorders. J Pediatr. 2001; 138(1 Suppl):S6-10.
8. Summar M. Current strategies for the management of neonatal urea cycle disorders. J Pediatr. 2001; 138(1 Suppl):S30-9.
9. Urea Cycle Disorders Conference group.. Consensus statement from a conference for the management of patients with urea cycle disorders. J Pediatr. 2001; 138(1 Suppl):S1-5.
10. Orphan Europe. How to use Carbaglu. From Carbaglu website. Accessed 2013 Jan 15.
11. Orphan Europe. Ordering Carbaglu. From Carbaglu website. Accessed 2013 Jan 18.
12. Accredo Health Group. Carbaglu (carglumic acid). From Accredo website. Accessed Jan 18.