Onfi Side Effects

Generic Name: clobazam

Note: This page contains side effects data for the generic drug clobazam. It is possible that some of the dosage forms included below may not apply to the brand name Onfi.

It is possible that some side effects of Onfi may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

For the Consumer

Applies to clobazam: oral suspension, oral tablet

As well as its needed effects, clobazam (the active ingredient contained in Onfi) may cause unwanted side effects that require medical attention.

If any of the following side effects occur while taking clobazam, check with your doctor immediately:

More common
  • Difficulty with swallowing
  • fever
  • shakiness and unsteady walk
  • unsteadiness, trembling, or other problems with muscle control or coordination
Less common
  • Change in speech pattern
  • restlessness
  • slurred speech
  • trouble sitting still
  • trouble speaking
Incidence not known
  • Agitation
  • black, tarry stools
  • bleeding gums
  • blistering, peeling, or loosening of the skin
  • blood in the urine or stools
  • chest pain
  • chills
  • confusion as to time, place, or person
  • cough
  • diarrhea
  • difficult or troubled breathing
  • holding false beliefs that cannot be changed by fact
  • irregular, fast or slow, or shallow breathing
  • itching
  • joint or muscle pain
  • lack of feeling or emotion
  • painful or difficult urination
  • pale or blue lips, fingernails, or skin
  • pinpoint red spots on the skin
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • seeing, hearing, or feeling things that are not there
  • sore throat
  • sores, ulcers, or white spots in the mouth or on the lips
  • swollen glands
  • troubled breathing with exertion
  • unusual bleeding or bruising
  • unusual excitement, nervousness, or restlessness
  • unusual tiredness or weakness

Some clobazam side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common
  • Aggressive
  • body aches or pain
  • decreased appetite
  • difficulty having a bowel movement (stool)
  • drooling
  • ear congestion
  • irritability
  • loss of voice
  • nasal congestion
  • runny nose
  • sleepiness or unusual drowsiness
  • sneezing
  • vomiting
Less common
  • Bladder pain
  • cloudy urine
  • cough with mucus
  • frequent urge to urinate
  • increased appetite
  • lower back or side pain
Incidence not known
  • Double vision
  • full or bloated feeling
  • headache
  • muscle spasms
  • pressure in the stomach
  • rash, hives, or welts
  • red skin
  • swelling of the stomach area

For Healthcare Professionals

Applies to clobazam: oral suspension, oral tablet


Dermatologic side effects reported postmarketing have included rash, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and urticaria.[Ref]


Gastrointestinal side effects have included vomiting (7%) and constipation (5%). Gastrointestinal side effects reported postmarketing have included abdominal distention.[Ref]


General side effects have included dysphagia (2%).[Ref]


Genitourinary side effects have included urinary tract infection (4%).[Ref]


Hematologic side effects reported postmarketing have included anemia, eosinophilia, leukopenia, and thrombocytopenia.[Ref]


Metabolic side effects have included decreased appetite (3%) and increased appetite (3%).[Ref]

Nervous system

Nervous system side effects have included pyrexia (13%), irritability (7%), fatigue (5%), somnolence (22%), sedation (5%), lethargy (10%), drooling (9%), ataxia (5%), psychomotor hyperactivity (4%), and dysarthria (3%).[Ref]


Ocular side effects reported postmarketing have included diplopia and blurred vision.[Ref]


Psychiatric side effects have included aggression (8%) and insomnia (5%). Psychiatric side effects reported postmarketing have included agitation, anxiety, apathy, confused state, depression, delirium, delusion, and hallucination.[Ref]


Respiratory side effects have included upper respiratory tract infection (4%), pneumonia (4%), bronchitis (2%), and cough (5%). Respiratory side effects reported postmarketing have included aspiration and respiratory depression.[Ref]


1. "Product Information. Onfi (clobazam)." Lundbeck Inc, Deerfield, IL.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.