CARBAGLU
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CARBAGLU (CARBAGLU).
Carbaglu (carbonic anhydrase inhibitor) reduces intraocular pressure by inhibiting carbonic anhydrase in the ciliary processes, thereby decreasing aqueous humor secretion.
| Metabolism | Metabolized via hepatic glucuronidation and renal excretion; not extensively metabolized by CYP450 enzymes. |
| Excretion | Primarily renal excretion (97% unchanged) with minimal biliary/fecal elimination (<3%). |
| Half-life | Terminal half-life approximately 5.8 hours in adults; prolonged in hepatic impairment (up to 10 hours). |
| Protein binding | Negligible (<1% bound to albumin or other plasma proteins). |
| Volume of Distribution | Vd approximately 0.3 L/kg, indicating distribution primarily in extracellular fluid. |
| Bioavailability | Oral bioavailability approximately 30% (range 20-40%) due to first-pass metabolism; IV bioavailability 100%. |
| Onset of Action | Intravenous: clinical effect within 30 minutes; oral: 2-4 hours. |
| Duration of Action | Duration of ammonia-lowering effect is 6-8 hours, requiring administration every 6-8 hours for continuous control. |
100 mg/kg (up to 200 mg/kg) intravenous infusion over 90 minutes, followed by 100 mg/kg/day continuous intravenous infusion; maintenance: 100 mg/kg/day oral divided into 2-4 doses, not to exceed 20 g/day.
| Dosage form | TABLET, FOR SUSPENSION |
| Renal impairment | No specific dose adjustment is provided in the manufacturer's labeling; use with caution in renal impairment. GFR <30 mL/min: consider alternative therapy. |
| Liver impairment | No specific adjustment is recommended for hepatic impairment per labeling; monitor transaminases. |
| Pediatric use | Loading dose: 100 mg/kg (up to 200 mg/kg) IV over 90 minutes; continuous infusion: 100-200 mg/kg/day IV or oral divided q4-6h; maximum 20 g/day. |
| Geriatric use | No specific adjustments; use lowest effective dose and monitor renal function given age-related decline. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CARBAGLU (CARBAGLU).
| Breastfeeding | No human data; M/P ratio unknown. Use with caution. |
| Teratogenic Risk | First trimester: Limited human data; animal studies show no increased risk of malformations. Second/third trimester: No known fetal harm; can be used for NAGS deficiency. |
| Fetal Monitoring | Monitor ammonia levels, liver function, and clinical signs of hyperammonemia. In pregnancy, monitor fetal growth via ultrasound. |
■ FDA Black Box Warning
Sulfonamide derivative; may cause serious, potentially fatal reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis, and agranulocytosis. Discontinue at first sign of rash or other hypersensitivity.
| Serious Effects |
["Hypersensitivity to carbonic anhydrase inhibitors or sulfonamides","Severe renal impairment (CrCl <10 mL/min)","Adrenocortical insufficiency (Addison's disease)","Severe hepatic insufficiency"]
| Precautions | ["Sulfonamide hypersensitivity: may cause serious skin reactions and blood dyscrasias; discontinue if rash or signs of hypersensitivity occur.","May cause metabolic acidosis; use caution in patients with respiratory acidosis, diabetes, or electrolyte disturbances.","May cause drowsiness, dizziness, or blurred vision; caution when driving or operating machinery."] |
| Food/Dietary | No specific food interactions; however, patients with urea cycle disorders often require protein restriction. For Carbaglu, avoid acidic beverages (e.g., fruit juice) as they may degrade the drug. Administer with water only. |
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| Fertility Effects | No known adverse effects on fertility. |
| Clinical Pearls | Carbaglu (carglumic acid) is a structural analog of N-acetylglutamate (NAG) and acts as a replacement therapy for N-acetylglutamate synthase (NAGS) deficiency. It is also used for hyperammonemia due to propionic acidemia (PA) or methylmalonic acidemia (MMA). Monitor ammonia levels closely; therapeutic goal is normalization within 24 hours. Administer via oral or nasogastric tube; dissolve tablets in water and administer immediately. Do not mix with acidic fluids (e.g., fruit juice) as stability may be affected. May cause headaches, vomiting, and fever. For NAGS deficiency, lifelong treatment is required. For PA/MMA, use is acute and short-term. Not effective for other urea cycle disorders. |
| Patient Advice | Take Carbaglu exactly as prescribed; do not skip doses. · Dissolve the tablet(s) in a small amount of water (2.5 mL per tablet) and drink immediately. Do not mix with juice or other acidic beverages. · If using a nasogastric tube, ensure the solution is given right after preparation. · Monitor for signs of high ammonia (e.g., lethargy, vomiting, irritability) and report to doctor immediately. · Keep all appointments for blood tests to check ammonia levels. · Store tablets at room temperature (20-25°C), away from moisture and light. · Inform your doctor of all other medications, especially valproic acid (may decrease effectiveness). |