Sodium Phenylbutyrate

Applies to sodium phenylbutyrate: oral powder, oral tablet

Along with its needed effects, sodium phenylbutyrate may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking sodium phenylbutyrate:

More common

• Change in the frequency of breathing
• lack of or irregular menstruation
• lower back, side, or stomach pain
• mood or mental changes
• muscle pain or twitching
• nausea or vomiting
• nervousness or restlessness
• swelling of the feet or lower legs
• unpleasant taste
• unusual tiredness or weakness

Less common

• Chills
• fever
• joint pain
• sore throat
• unusual bleeding or bruising

Rare

• Convulsions (seizures)
• dizziness
• dryness of the mouth
• fast, slow, or irregular heartbeat
• increased blood pressure
• increased thirst
• irritability
• muscle cramps
• rectal bleeding
• swelling of the face
• unusual weight gain
• weak pulse

Some side effects of sodium phenylbutyrate may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

• Changes in taste
• decreased appetite
• strong body odor

Rare

• Abdominal or stomach pain
• constipation
• fainting
• headache
• mental depression
• skin rash

Applies to sodium phenylbutyrate: oral powder for reconstitution, oral tablet

Causality of adverse effects is sometimes difficult to determine because they may result from either the underlying disease, the patient's restricted diet, intercurrent illness, or the drug itself.

Very common (10% or more): Amenorrhea/menstrual dysfunction (23%)

Very common (10% or more): Acidosis (14%), hypoalbuminemia (11%)

Common (1% to 10%): Alkalosis, decreased appetite, hyperchloremia, hypophosphatemia, decreased total protein, hyperuricemia, hyperphosphatemia, hypernatremia, hypokalemia, increased weight

Common (1% to 10%): Edema

Uncommon (0.1% to 1%): Arrhythmia

Common (1% to 10%): Rash, body odor

Common (1% to 10%): Abdominal pain, nausea, vomiting, constipation, dysgeusia

Uncommon (0.1% to 1%): Pancreatitis, rectal bleeding/hemorrhage, peptic ulcer, gastritis

Common (1% to 10%): Anemia, leukopenia, leukocytosis, thrombocytopenia, thrombocytosis

Uncommon (0.1% to 1%): Aplastic anemia, ecchymosis

Common (1% to 10%): Increased alkaline phosphatase, increased liver transaminases, hyperbilirubinemia

Common (1% to 10%): Syncope, headache, bad taste/taste aversion

Frequency not reported: Somnolence, fatigue, lightheadedness, hypoacusis, disorientation, impaired memory, exacerbation of preexisting neuropathy

Common (1% to 10%): Depression, irritability

Common (1% to 10%): Renal tubular acidosis