Medical Editor: John P. Cunha, DO, FACOEP
Ozobax (baclofen) is a gamma-aminobutyric acid (GABA-ergic) agonist indicated for the treatment of spasticity resulting from multiple sclerosis, particularly for the relief of flexor spasms and concomitant pain, clonus, and muscular rigidity. Ozobax may also be of some value in patients with spinal cord injuries and other spinal cord diseases. Common side effects of Ozobax includeL
- drowsiness,
- dizziness,
- weakness,
- nausea,
- confusion,
- low blood pressure (hypotension),
- headache,
- difficulty sleeping (insomnia),
- constipation,
- urinary frequency, and
- fatigue
Initiate Ozobax with a low dosage, preferably in divided doses, administered orally. Increase gradually based on clinical response and tolerability. The maximum dose of Ozobax is 80 mg daily (20 mg four times a day). Ozobax may interact with other CNS depressants or alcohol. Tell your doctor all medications and supplements you use. Ozobax is not recommended for use during pregnancy; it may harm a fetus. Ozobax passes into breast milk. Withdrawal symptoms can occur in breastfed infants when maternal administration of Ozobax is stopped, or when breastfeeding is stopped. Consult your doctor before breastfeeding. Withdrawal symptoms such as hallucinations, seizures, high fever, altered mental status, exaggerated rebound spasticity, and muscle rigidity may occur if you suddenly stop taking Ozobax.
Our Ozobax (baclofen) Oral Solution Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

SLIDESHOW
What Is Multiple Sclerosis? MS Symptoms, Causes, Diagnosis See SlideshowSIDE EFFECTS
The following clinically significant adverse reactions are described elsewhere in the labeling:
- Adverse Reactions from Abrupt Withdrawal of OZOBAX [see WARNINGS AND PRECAUTIONS]
- Neonatal Withdrawal Symptoms [see WARNINGS AND PRECAUTIONS]
- Drowsiness and Sedation [see WARNINGS AND PRECAUTIONS]
- Poor Tolerability in Stroke Patients [see WARNINGS AND PRECAUTIONS]
- Exacerbation of Psychotic Disorders, Schizophrenia, or Confusional States [see WARNINGS AND PRECAUTIONS]
- Exacerbation of Autonomic Dysreflexia [see WARNINGS AND PRECAUTIONS]
- Exacerbation of Epilepsy [see WARNINGS AND PRECAUTIONS]
- Posture and Balance Effects [see WARNINGS AND PRECAUTIONS]
- Ovarian Cysts [see WARNINGS AND PRECAUTIONS]
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The most common adverse reaction is transient drowsiness. In one controlled study of 175 patients, transient drowsiness was observed in 63% of those receiving baclofen compared to 36% of those in the placebo group. Other common adverse reactions (up to 15%) are dizziness and weakness. Adverse reactions with a frequency of ≥1% are listed in Table 1.
Table 1:Common (≥1%) Adverse Reactions in
Patients Treated with Baclofen for Spasticity
ADVERSE REACTION | PERCENT |
Drowsiness | 10-63% |
Dizziness | 5-15% |
Weakness | 5-15% |
Nausea | 4-12% |
Confusion | 1-11% |
Hypotension | 0-9% |
Headache | 4-8% |
Insomnia | 2-7% |
Constipation | 2-6% |
Urinary Frequency | 2-6% |
Fatigue | 2-4% |
The following adverse reactions not included in Table 1, classified by body system, were also reported:
Neuropsychiatric: euphoria, excitement, depression, hallucinations, paresthesia, muscle pain, tinnitus, slurred speech, coordination disorder, tremor, rigidity, dystonia, ataxia, blurred vision, nystagmus, strabismus, miosis, mydriasis, diplopia, dysarthria, epileptic seizure
Cardiovascular: dyspnea, palpitation, chest pain, syncope
Gastrointestinal: dry mouth, anorexia, taste disorder, abdominal pain, vomiting, diarrhea, and positive test for occult blood in stool
Genitourinary: enuresis, urinary retention, dysuria, impotence, inability to ejaculate, nocturia, hematuria
Other: rash, pruritus, ankle edema, excessive perspiration, weight gain, nasal congestion
The following laboratory tests have been found to be abnormal in patients receiving baclofen: increased SGOT, elevated alkaline phosphatase, and elevation of blood sugar.
Read the entire FDA prescribing information for Ozobax (Baclofen Oral Solution)
