AUTHORIZATION Horizon Can Help Support Patients at Every Step of the Access Process

BUPHENYL® (sodium phenylbutyrate) Tablets or Powder treatment may require initial action from the HCP and office staff for patients to get access.

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How Does the Access Process Work?

Benefits Investigation

Horizon By Your Side Can Assist You With the Benefits Investigation (BI) Process

Our team will contact your patient’s insurance company to review coverage and work with the patient to ensure they understand:

  • Whether the medicine is covered by their policy
  • Any estimated out-of-pocket costs and financial assistance that may be available
  • All PA requirements

Prior Authorization

Your Patient May Need a Prior Authorization (PA) Before Beginning BUPHENYL

Health plans sometimes require a PA before approving coverage of medicine. Also referred to as a preauthorization or precertification, this is a process that your office must complete, describing the reasons your patient should be prescribed BUPHENYL and why the health plan should cover the costs. PAs are commonly required for medicines that treat rare diseases.

The requirements for a PA will differ from health plan to health plan. Your office must complete and submit all required forms and provide other information and documents requested.

Woman at keyboard

Some of the items commonly required for a PA are:

  • A letter of medical necessity (downloadable sample below)
  • Health plan identification numbers
  • Confirmation of diagnosis, including test results
  • Your patient’s medical history, including previously tried and failed medications and lifestyle modifications
  • Medical articles about the disease and the Horizon medicine being prescribed
  • Plan-specific PA forms (when applicable)

Appeal

If a PA Is Denied, an Appeal Can Be Submitted

An appeal letter may be needed if a PA for BUPHENYL is denied. When writing an appeal letter, ensure that you address the specific details of the denial reason(s). Refer to the letter of denial for specific language regarding the reason and address any patient-specific concerns.

Supplemental documentation may include:

  • Relevant clinical notes for your patient
  • Recent test results
  • Supporting scientific publications/journal articles
  • A summary of your recommendation at the end of the letter
  • A letter of medical necessity

Make sure you match the exact language in the denial letter. It is imperative to address the specifics of the denial in the appeal. Before you submit your appeal, be sure to:

  • Check for any incomplete or missing information, a common reason for denial 
  • Schedule a peer-to-peer meeting with health plan
  • Contact a Case Manager to learn about additional resources and next steps in the process

Familiarize yourself with important forms and downloadable resources that explain the process

Forms and Downloads

See how Horizon By Your Side may be able to offer financial assistance for your patients on BUPHENYL

Financial Assistance
Enroll Your Patient
Patient Enrollment Form

Download PDF

Learn more about patient enrollment

INDICATION and IMPORTANT SAFETY INFORMATION

INDICATION

BUPHENYL® (sodium phenylbutyrate) Tablets for oral administration and BUPHENYL® (sodium phenylbutyrate) Powder for oral, nasogastric, or gastrostomy tube administration are indicated as adjunctive therapy in the chronic management of patients with urea cycle disorders (UCDs) involving deficiencies of carbamoyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS).

BUPHENYL is indicated in all patients with neonatal-onset deficiency (complete enzymatic deficiency, presenting within the first 28 days of life). It is also indicated in patients with late-onset disease (partial enzymatic deficiency, presenting after the first month of life) who have a history of hyperammonemic encephalopathy.

BUPHENYL must be used with dietary protein restriction and, in some cases, essential amino acid supplementation.

Any episode of acute hyperammonemia should be treated as a life-threatening emergency.

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

  • Acute hyperammonemia: BUPHENYL should not be used to manage acute hyperammonemia, which is a medical emergency.

WARNINGS AND PRECAUTIONS

BUPHENYL should not be administered to patients with known hypersensitivity to sodium phenylbutyrate or any component of this preparation.

  • Use caution with administering BUPHENYL to patients with:
    • Congestive heart failure or severe renal insufficiency, and in clinical states in which there is sodium retention with edema.
    • Hepatic or renal insufficiency or inborn errors of beta oxidation.
  • Probenecid may affect renal excretion of the conjugated product of BUPHENYL as well as its metabolite.
  • Use of corticosteroids may cause the breakdown of body protein and increase plasma ammonia levels.
  • There have been published reports of hyperammonemia being induced by haloperidol and by valproic acid.

ADVERSE REACTIONS

  • The most common adverse reactions (≥3%) reported in BUPHENYL clinical trials were decreased appetite, body odor, bad taste or taste aversion.
  • In female patients, amenorrhea/menstrual dysfunction (irregular menstrual cycles) occurred in 23% of the menstruating patients.
  • Neurotoxicity was reported in cancer patients receiving intravenous phenylacetate. Manifestations were predominately somnolence, fatigue, and lightheadedness; with less frequent headache, dysgeusia, hypoacusis, disorientation, impaired memory, and exacerbation of a pre-existing neuropathy.
  • Laboratory adverse events occurring in >2% of UCD patients by body system were:
    • Metabolic: acidosis, alkalosis, hyperchloremia, and hypophosphatemia
    • Nutritional: hypoalbuminemia and decreased total protein
    • Hepatic: increased alkaline phosphatase and increased liver transaminases
    • Hematologic: anemia, leukopenia, leukocytosis, and thrombocytopenia

USE IN SPECIFIC POPULATIONS

  • Pregnancy: BUPHENYL should be used with caution in patients who are pregnant or planning to become pregnant. Animal reproduction studies have not been conducted with BUPHENYL. It is not known whether BUPHENYL can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.
  • Lactation: breastfeeding is not recommended during treatment with BUPHENYL. There are no data on the presence of BUPHENYL in human milk.

Please see Full Prescribing Information.

INDICATION and IMPORTANT SAFETY INFORMATION

INDICATION

BUPHENYL® (sodium phenylbutyrate) Tablets for oral administration and BUPHENYL® (sodium phenylbutyrate) Powder for oral, nasogastric, or gastrostomy tube administration are indicated as adjunctive therapy in the chronic management of patients with urea cycle disorders (UCDs) involving deficiencies of carbamoyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS).

BUPHENYL is indicated in all patients with neonatal-onset deficiency (complete enzymatic deficiency, presenting within the first 28 days of life). It is also indicated in patients with late-onset disease (partial enzymatic deficiency, presenting after the first month of life) who have a history of hyperammonemic encephalopathy.

BUPHENYL must be used with dietary protein restriction and, in some cases, essential amino acid supplementation.

Any episode of acute hyperammonemia should be treated as a life-threatening emergency.

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

  • Acute hyperammonemia: BUPHENYL should not be used to manage acute hyperammonemia, which is a medical emergency.

WARNINGS AND PRECAUTIONS

BUPHENYL should not be administered to patients with known hypersensitivity to sodium phenylbutyrate or any component of this preparation.

  • Use caution with administering BUPHENYL to patients with:
    • Congestive heart failure or severe renal insufficiency, and in clinical states in which there is sodium retention with edema.
    • Hepatic or renal insufficiency or inborn errors of beta oxidation.
  • Probenecid may affect renal excretion of the conjugated product of BUPHENYL as well as its metabolite.
  • Use of corticosteroids may cause the breakdown of body protein and increase plasma ammonia levels.
  • There have been published reports of hyperammonemia being induced by haloperidol and by valproic acid.

ADVERSE REACTIONS

  • The most common adverse reactions (≥3%) reported in BUPHENYL clinical trials were decreased appetite, body odor, bad taste or taste aversion.
  • In female patients, amenorrhea/menstrual dysfunction (irregular menstrual cycles) occurred in 23% of the menstruating patients.
  • Neurotoxicity was reported in cancer patients receiving intravenous phenylacetate. Manifestations were predominately somnolence, fatigue, and lightheadedness; with less frequent headache, dysgeusia, hypoacusis, disorientation, impaired memory, and exacerbation of a pre-existing neuropathy.
  • Laboratory adverse events occurring in >2% of UCD patients by body system were:
    • Metabolic: acidosis, alkalosis, hyperchloremia, and hypophosphatemia
    • Nutritional: hypoalbuminemia and decreased total protein
    • Hepatic: increased alkaline phosphatase and increased liver transaminases
    • Hematologic: anemia, leukopenia, leukocytosis, and thrombocytopenia

USE IN SPECIFIC POPULATIONS

  • Pregnancy: BUPHENYL should be used with caution in patients who are pregnant or planning to become pregnant. Animal reproduction studies have not been conducted with BUPHENYL. It is not known whether BUPHENYL can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.
  • Lactation: breastfeeding is not recommended during treatment with BUPHENYL. There are no data on the presence of BUPHENYL in human milk.

Please see Full Prescribing Information.

INDICATION and IMPORTANT SAFETY INFORMATION

INDICATION

BUPHENYL® (sodium phenylbutyrate) Tablets for oral administration and BUPHENYL® (sodium phenylbutyrate) Powder for oral, nasogastric, or gastrostomy tube administration are indicated as adjunctive therapy in the chronic management of patients with urea cycle disorders (UCDs) involving deficiencies of carbamoyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS).

BUPHENYL is indicated in all patients with neonatal-onset deficiency (complete enzymatic deficiency, presenting within the first 28 days of life). It is also indicated in patients with late-onset disease (partial enzymatic deficiency, presenting after the first month of life) who have a history of hyperammonemic encephalopathy.

BUPHENYL must be used with dietary protein restriction and, in some cases, essential amino acid supplementation.

Any episode of acute hyperammonemia should be treated as a life-threatening emergency.

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

  • Acute hyperammonemia: BUPHENYL should not be used to manage acute hyperammonemia, which is a medical emergency.

WARNINGS AND PRECAUTIONS

BUPHENYL should not be administered to patients with known hypersensitivity to sodium phenylbutyrate or any component of this preparation.

  • Use caution with administering BUPHENYL to patients with:
    • Congestive heart failure or severe renal insufficiency, and in clinical states in which there is sodium retention with edema.
    • Hepatic or renal insufficiency or inborn errors of beta oxidation.
  • Probenecid may affect renal excretion of the conjugated product of BUPHENYL as well as its metabolite.
  • Use of corticosteroids may cause the breakdown of body protein and increase plasma ammonia levels.
  • There have been published reports of hyperammonemia being induced by haloperidol and by valproic acid.

ADVERSE REACTIONS

  • The most common adverse reactions (≥3%) reported in BUPHENYL clinical trials were decreased appetite, body odor, bad taste or taste aversion.
  • In female patients, amenorrhea/menstrual dysfunction (irregular menstrual cycles) occurred in 23% of the menstruating patients.
  • Neurotoxicity was reported in cancer patients receiving intravenous phenylacetate. Manifestations were predominately somnolence, fatigue, and lightheadedness; with less frequent headache, dysgeusia, hypoacusis, disorientation, impaired memory, and exacerbation of a pre-existing neuropathy.
  • Laboratory adverse events occurring in >2% of UCD patients by body system were:
    • Metabolic: acidosis, alkalosis, hyperchloremia, and hypophosphatemia
    • Nutritional: hypoalbuminemia and decreased total protein
    • Hepatic: increased alkaline phosphatase and increased liver transaminases
    • Hematologic: anemia, leukopenia, leukocytosis, and thrombocytopenia

USE IN SPECIFIC POPULATIONS

  • Pregnancy: BUPHENYL should be used with caution in patients who are pregnant or planning to become pregnant. Animal reproduction studies have not been conducted with BUPHENYL. It is not known whether BUPHENYL can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.
  • Lactation: breastfeeding is not recommended during treatment with BUPHENYL. There are no data on the presence of BUPHENYL in human milk.

Please see Full Prescribing Information.

INDICATION and IMPORTANT SAFETY INFORMATION

INDICATION

BUPHENYL® (sodium phenylbutyrate) Tablets for oral administration and BUPHENYL® (sodium phenylbutyrate) Powder for oral, nasogastric, or gastrostomy tube administration are indicated as adjunctive therapy in the chronic management of patients with urea cycle disorders (UCDs) involving deficiencies of carbamoyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS).

BUPHENYL is indicated in all patients with neonatal-onset deficiency (complete enzymatic deficiency, presenting within the first 28 days of life). It is also indicated in patients with late-onset disease (partial enzymatic deficiency, presenting after the first month of life) who have a history of hyperammonemic encephalopathy.

BUPHENYL must be used with dietary protein restriction and, in some cases, essential amino acid supplementation.

Any episode of acute hyperammonemia should be treated as a life-threatening emergency.

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

  • Acute hyperammonemia: BUPHENYL should not be used to manage acute hyperammonemia, which is a medical emergency.

WARNINGS AND PRECAUTIONS

BUPHENYL should not be administered to patients with known hypersensitivity to sodium phenylbutyrate or any component of this preparation.

  • Use caution with administering BUPHENYL to patients with:
    • Congestive heart failure or severe renal insufficiency, and in clinical states in which there is sodium retention with edema.
    • Hepatic or renal insufficiency or inborn errors of beta oxidation.
  • Probenecid may affect renal excretion of the conjugated product of BUPHENYL as well as its metabolite.
  • Use of corticosteroids may cause the breakdown of body protein and increase plasma ammonia levels.
  • There have been published reports of hyperammonemia being induced by haloperidol and by valproic acid.

ADVERSE REACTIONS

  • The most common adverse reactions (≥3%) reported in BUPHENYL clinical trials were decreased appetite, body odor, bad taste or taste aversion.
  • In female patients, amenorrhea/menstrual dysfunction (irregular menstrual cycles) occurred in 23% of the menstruating patients.
  • Neurotoxicity was reported in cancer patients receiving intravenous phenylacetate. Manifestations were predominately somnolence, fatigue, and lightheadedness; with less frequent headache, dysgeusia, hypoacusis, disorientation, impaired memory, and exacerbation of a pre-existing neuropathy.
  • Laboratory adverse events occurring in >2% of UCD patients by body system were:
    • Metabolic: acidosis, alkalosis, hyperchloremia, and hypophosphatemia
    • Nutritional: hypoalbuminemia and decreased total protein
    • Hepatic: increased alkaline phosphatase and increased liver transaminases
    • Hematologic: anemia, leukopenia, leukocytosis, and thrombocytopenia

USE IN SPECIFIC POPULATIONS

  • Pregnancy: BUPHENYL should be used with caution in patients who are pregnant or planning to become pregnant. Animal reproduction studies have not been conducted with BUPHENYL. It is not known whether BUPHENYL can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity.
  • Lactation: breastfeeding is not recommended during treatment with BUPHENYL. There are no data on the presence of BUPHENYL in human milk.

Please see Full Prescribing Information.