In September 2008, Ucyclyd Pharma, Inc. (Ucyclyd) detected particulate matter in its AMMONUL (sodium phenylacetate and sodium benzoate) Injection 10%/10% product. Due to the possibility that this particulate matter may impact the safe use of this product and to ensure optimal patient care, you are instructed to use the Millex^® Durapore GV 33 mm Sterile Syringe Filter (0.22 µm) during the admixture process when injecting AMMONUL into the 10% dextrose IV bag. Please note that this particulate matter may not be readily seen on visual inspection, so this filter must be employed in all cases regardless of whether particulate matter is seen in the vial. This filter was chosen because it is made from the same materials as the validated cartridge filters used in the processing of the drug product and it is rated to remove particles 0.22 µm and larger. Testing has confirmed the removal of this specific particulate matter when using this filter to admix AMMONUL.

AMMONUL (sodium phenylacetate and sodium benzoate) Injection 10%/10% is the only FDA-approved drug for the adjunctive treatment of acute hyperammonemia and associated encephalopathy in patients with urea cycle disorders (UCDs). During acute hyperammonemic episodes, arginine supplementation, caloric supplementation, dietary protein restriction, hemodialysis, and other ammonia-lowering therapies should be considered.

Left untreated, UCDs can cause dangerously heightened levels of ammonia in the bloodstream (hyperammonemia) resulting in brain damage, coma, and/or death.

Important Safety Information for AMMONUL Injection 10% / 10%

• IMPORTANT: Filtration required. Due to the possibility that particulate matter may impact the safe use of this product and to ensure optimal patient care, you are instructed to use the Millex^® Durapore GV 33 mm Sterile Syringe Filter (0.22 μm) during the admixture process when injecting AMMONUL into the 10% dextrose IV bag. Note that particulate matter may not be readily seen on visual inspection, so this filter must be employed in all cases regardless of whether particulate matter is seen in the vial.
• The most common adverse reactions are vomiting (9%), hyperglycemia (7%), hypokalemia (7%), convulsions (6%), and mental impairment (6%).
• Dilute AMMONUL with sterile 10% Dextrose Injection (D10W) before administration. Use a central venous catheter line; use of a peripheral line may cause burns.
• Monitor patients for prolonged exposure to elevated plasma ammonia levels as this can rapidly result in injury to the brain or death. Promptly use any therapies necessary to reduce plasma ammonia levels.
• Monitor plasma potassium levels carefully and treat as necessary.
• Use caution if AMMONUL is administered to patients with congestive heart failure, severe renal insufficiency, or with a condition in which there is sodium retention with edema.
• Monitor the infusion site for possible tissue infiltration since extravasation of AMMONUL into the perivenous tissues during high flow bolus infusion may lead to skin necrosis, especially in infants.
• Do not administer repeat loading doses because of prolonged plasma levels achieved by phenylacetate in pharmacokinetic studies.
• Monitor patient blood chemistry profiles and perform frequent blood pH and pCO₂ measurements because AMMONUL may cause side effects typically associated with salicyclate overdose such as hyperventilation and metabolic acidosis.
• Administration of valproic acid to patients with urea cycle disorders may exacerbate their condition and antagonize the efficacy of AMMONUL.

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