Ammonul Side Effects

Generic name: sodium benzoate / sodium phenylacetate

Medically reviewed by Drugs.com. Last updated on Mar 24, 2025.

Note: This document provides detailed information about Ammonul Side Effects associated with sodium benzoate / sodium phenylacetate. Some dosage forms listed on this page may not apply specifically to the brand name Ammonul.

Applies to sodium benzoate / sodium phenylacetate: oral solution.

Other dosage forms:

• intravenous solution

Serious side effects of Ammonul

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

Stop taking sodium benzoate / sodium phenylacetate and get emergency help immediately if any of the following effects occur:

More common side effects

• confusion
• convulsions
• decreased urine
• dry mouth
• headache
• increase in frequency of seizures
• increased thirst
• irregular heartbeat
• loss of appetite
• mood changes
• muscle pain or cramps
• nausea
• numbness or tingling in hands, feet, or lips
• problems with movement, walking or speech
• shortness of breath
• swelling of face
• unusual tiredness or weakness
• vomiting
• yellow eyes or skin

Less common side effects

• blood in stools
• blood in urine
• bruising
• change in consciousness
• coughing or vomiting blood
• difficulty in breathing
• drowsiness
• loss of consciousness
• mental changes
• muscle cramps in hands, arms, feet, legs, or face
• muscle tremors
• persistent bleeding or oozing from puncture sites, mouth, or nose
• rapid, deep breathing
• rash
• restlessness
• shortness of breath
• stomach cramps
• tightness in chest
• tremor
• troubled breathing
• wheezing

Frequency unknown

• abnormally slow deep breathing
• blue lips, fingernails, or skin
• blurred vision
• bulging soft spot on head of an infant
• change in ability to see colors, especially blue or yellow
• chest pain or discomfort
• dizziness or fainting
• injection site hemorrhage
• insomnia
• irregular, fast or slow, or shallow breathing
• lightheadedness
• severe headache
• shakiness
• sleepiness
• slow heartbeat
• slow to respond
• slurred speech
• unconsciousness

Symptoms of overdose

• agitation
• back pain
• blue lips, fingernails, or skin
• blurred vision
• bulging soft spot on head of an infant
• change in ability to see colors, especially blue or yellow
• chest pain or discomfort
• chills
• cold, clammy, pale skin
• coma
• confusion
• continuing nausea or vomiting
• cough
• deep or fast breathing with dizziness
• difficult or troubled breathing
• dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly
• drowsiness
• fainting
• fast heartbeat
• fever
• general feeling of discomfort or illness
• hallucinations
• headache
• high blood pressure
• insomnia
• irregular, fast or slow, or shallow breathing
• irregular heartbeats
• irritability
• lightheadedness
• loss of appetite
• mood or mental changes
• muscle twitching
• no blood pressure
• not alert
• numbness to feet, hands and around mouth
• rapid, shallow breathing
• restlessness
• seizures
• slow heart rate
• stiff neck
• sweating
• swelling of face
• swelling of feet or lower legs
• thickening of bronchial secretions
• trouble with coordination
• unusual tiredness or weakness
• vomiting
• weakness
• yellow eyes or skin

Other side effects of Ammonul

Some side effects of sodium benzoate / sodium phenylacetate 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:

More common side effects

• changes in skin color
• cold hands and feet
• confusion or excitement
• cough or hoarseness;
• dry mouth;
• fever or chills
• flushed, dry skin;
• fruit-like breath odor
• increased hunger
• increased thirst
• increased urination
• lower back or side pain
• mental depression or anxiety
• nightmares or unusually vivid dreams
• painful or difficult urination
• pain, redness, or swelling in arm or leg
• skin disorders
• sweating
• unexplained weight loss

Less common side effects

• bladder pain
• bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection; inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at site
• decrease in urine-concentrating ability
• diarrhea
• difficult, burning, or painful urination
• frequent urge to urinate
• hyperventilation
• nervousness
• pale skin
• shaking
• troubled breathing with exertion
• trouble sleeping
• unusual bleeding or bruising

Frequency unknown

• blister
• full or bloated feeling or pressure in the stomach
• itching skin
• rash with flat lesions or small raised lesions on the skin
• swelling of abdominal or stomach area
• uncontrolled jerking movement

For healthcare professionals

Applies to sodium benzoate / sodium phenylacetate: intravenous solution.

General adverse events

The most frequently reported adverse reactions (incidence 6% or greater) are vomiting, hyperglycemia, hypokalemia, convulsions, and mental impairment.

Patients 30 days of age or younger had more blood and lymphatic system disorders and vascular disorders (specifically hypotension), while patients older than 30 days had more GI disorders (specifically nausea, vomiting, and diarrhea).^[Ref]

Nervous system

• Very common (10% or more): Nervous system disorders (22%)
• Common (1% to 10%): Convulsions, mental impairment, brain edema, coma
• Frequency not reported: Brain death, brain herniation, subdural hematoma, areflexia, ataxia, brain infarction, brain hemorrhage, cerebral atrophy, clonus, depressed level of consciousness, encephalopathy, nerve paralysis, increased intracranial pressure, tremor^[Ref]

Metabolic

• Very common (10% or more): Metabolism and nutrition disorders (21%)
• Common (1% to 10%): Hyperglycemia, hypokalemia, hyperammonemia, metabolic acidosis, hypocalcemia, acidosis
• Frequency not reported: Blood carbon dioxide changes, blood glucose changes, increased blood pH, partial pressure of carbon dioxide changes, alkalosis, dehydration, fluid overload/retention, hypoglycemia, hyperkalemia, hypernatremia, alkalosis, tetany^[Ref]

Respiratory

• Very common (10% or more): Respiratory, thoracic, and mediastinal disorders (15%)
• Common (1% to 10%): Respiratory distress
• Frequency not reported: Increased respiratory rate, acute respiratory distress syndrome, dyspnea, hypercapnia, hyperventilation, Kussmaul respiration, pneumonia aspiration, pneumothorax, pulmonary hemorrhage, pulmonary edema, respiratory acidosis, respiratory alkalosis, respiratory arrest/failure^[Ref]

Other

• Very common (10% or more): General disorders and administration-site conditions (14%), infections (12%), investigations (10%)
• Common (1% to 10%): Injury, poisoning, and procedural complications; pyrexia; injection-site reaction
• Frequency not reported: Asthenia, chest pain, multiorgan failure, edema, sepsis/septic shock, overdose^[Ref]

Gastrointestinal

• Very common (10% or more): GI disorders (13%)
• Common (1% to 10%): Vomiting, diarrhea, nausea
• Frequency not reported: Abdominal distension, GI hemorrhage^[Ref]

Hematologic

• Very common (10% or more): Blood and lymphatic system disorders (11%)
• Common (1% to 10%): Anemia, disseminated intravascular coagulation
• Frequency not reported: Coagulopathy, pancytopenia, thrombocytopenia^[Ref]

Cardiovascular

• Common (1% to 10%): Cardiac disorders, vascular disorders, hypotension
• Frequency not reported: Atrial rupture, bradycardia, cardiac or cardiopulmonary arrest/failure, cardiogenic shock, cardiomyopathy, pericardial effusion, decreased cardiac output, flushing, hemorrhage, hypertension, phlebothrombosis/thrombosis^[Ref]

Dermatologic

• Common (1% to 10%): Skin and subcutaneous tissue disorders
• Frequency not reported: Alopecia, blister, generalized pruritus, rash, urticaria^[Ref]

Genitourinary

• Common (1% to 10%): Urinary tract infection
• Frequency not reported: Anuria, urinary retention^[Ref]

Psychiatric

• Common (1% to 10%): Psychiatric disorders, agitation
• Frequency not reported: Acute psychosis, aggression, confusional state, hallucinations^[Ref]

Renal

• Common (1% to 10%): Renal and urinary disorders
• Frequency not reported: Renal failure^[Ref]

Hepatic

• Frequency not reported: Cholestasis, hepatic artery stenosis, hepatic failure, hepatotoxicity, jaundice^[Ref]

Ocular

• Frequency not reported: Blindness^[Ref]

Oncologic

• Frequency not reported: Acquired hemangioma^[Ref]

Further information

Ammonul side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer