Drug Information for AMMONUL (sodium phenylacetate and sodium benzoate) Injection 10% / 10% (Ucyclyd Pharma Inc.): WARNINGS

  • Any episode of acute symptomatic hyperammonemia should be treated as a life-threatening emergency. Treatment of hyperammonemia may require dialysis, preferably hemodialysis, to remove a large burden of ammonia. Uncontrolled hyperammonemia can rapidly result in brain damage or death, and prompt use of all therapies necessary to reduce ammonia levels is essential.

    Management of hyperammonemia due to inborn errors of metabolism should be done in coordination with medical personnel familiar with these diseases. The severity of the disorder may necessitate the use of hemodialysis combined with nutritional management and medical support. The multidisciplinary nature of the treatment usually requires the facilities of a tertiary or quaternary care center.

    Ongoing monitoring of plasma ammonia levels, neurological status, laboratory tests, and clinical response in patients receiving AMMONUL® is crucial to assess patient response to treatment. Because urine potassium loss is enhanced by the excretion of the non-reabsorbable anions, phenylacetylglutamine and hippurate, plasma potassium levels should be carefully monitored and appropriate treatment given when necessary. Serum electrolyte levels should be monitored and maintained within the normal range.

    AMMONUL® contains 30.5 mg of sodium per mL of undiluted product. Thus, AMMONUL® should be used with great care, if at all, in patients with congestive heart failure or severe renal insufficiency, and in clinical states in which there is sodium retention with edema. If an adverse reaction does occur, discontinue administration of AMMONUL®, evaluate the patient, and institute appropriate therapeutic countermeasures.

    Administration must be through a central line. Administration through a peripheral line may cause burns.

    Bolus infusion flow rates are relatively high, especially for infants (see DOSAGE AND ADMINISTRATION). Extravasation of AMMONUL® into the perivenous tissues may lead to skin necrosis. If extravasation is suspected, discontinue the infusion and resume at a different infusion site, if necessary. Standard treatment for extravasation can include aspiration of residual drug from the catheter, limb elevation, and intermittent cooling using cold packs [14]. The infusion site must be monitored closely for possible infiltration during drug administration. Do not administer undiluted product.

    Due to structural similarities between phenylacetate and benzoate to salicylate, AMMONUL® may cause side effects typically associated with salicylate overdose, such as hyperventilation and metabolic acidosis. The clinician is advised to perform blood chemistry profiles, and frequent blood pH and pCO2 monitoring.

  • Drug Information Provided by National Library of Medicine (NLM).