Baclofen Side Effects

Medically reviewed by Drugs.com. Last updated on Jan 17, 2025.

For healthcare professionals

Applies to baclofen: compounding powder, intrathecal solution, oral granule, oral liquid, oral solution, oral suspension, oral tablet.

Cardiovascular adverse events

• Common (1% to 10%): Cardiac output decreased, hypotension, hypertension, diminished cardiovascular functions, peripheral edema
• Rare (less than 0.1%): Arrhythmias, palpitations, chest pain
• Frequency not reported: Bradycardia, orthostatic hypotension^[Ref]

Dermatologic

• Common (1% to 10%): Rash, hyperhidrosis, urticaria/pruritus, facial edema
• Uncommon (0.1% to 1%): Alopecia, diaphoresis
• Frequency not reported: Rash, sweating, contact dermatitis, skin ulcer^[Ref]

Endocrine

• Common (1% to 10%): Ovarian cysts are palpable in 4% of women treated with for up to one year^[Ref]

Gastrointestinal

• Very common (10% or more): Nausea (especially at start of therapy) (up to 11%)
• Common (1% to 10%): Dry mouth, GI disorder/disturbance, constipation, diarrhea, retching, vomiting, increased salivation
• Uncommon (0.1% to 1%): Dysphagia, dehydration, ileus, decreased taste sensation
• Rare (less than 0.1%): Colicky abdominal pain, anorexia
• Frequency not reported: GI hemorrhage^[Ref]

Genitourinary

• Very common (10% or more): Urinary retention (up to 12%)
• Common (1% to 10%): Urinary incontinence, urination impaired, sexual dysfunction, urinary frequency, enuresis, dysuria
• Rare (less than 0.1%): Erectile dysfunction
• Frequency not reported: Dysuria, abnormal ejaculation, oliguria, vaginitis^[Ref]

Hematologic

• Frequency not reported: Leukocytosis, petechial rash^[Ref]

Hepatic

• Rare (less than 0.1%): Disorders of hepatic function (e.g., increased AST)^[Ref]

Immunologic

• Common (1% to 10%): Pneumonia
• Uncommon (0.1% to 1%): Septicemia^[Ref]

Metabolic

• Common (1% to 10%): Decreased appetite
• Frequency not reported: Blood glucose increased^[Ref]

Musculoskeletal

• Very common (10% or more): Hypotonia (up to 52%), lower extremity weakness (up to 15%), disturbances of gait and balance
• Common (1% to 10%): Muscular weakness, myalgia, upper extremity weakness, back pain, muscular hypertonia^[Ref]

Nervous system

• Very common (10% or more): Somnolence (up to 28%), drowsiness (up to 18%), headache (up to 16%), seizures (especially on discontinuation of therapy) (up to 15%), sedation, dizziness (up to 12%)
• Common (1% to 10%): Fatigue, ataxia, tremor, lightheadedness, lassitude, exhaustion, numbness/itching/tingling, slurred speech, lethargy, hypertonia, paresthesia
• Rare (less than 0.1%): Dysarthria, dysgeusia, syncope, dyskinesia, coma, potentially life-threatening withdrawal symptoms (as a result of sudden interruption of drug delivery)^[Ref]

Other

• Common (1% to 10%): Tinnitus, pain, asthenia
• Uncommon (0.1% to 1%): Accidental injury, weight loss
• Very rare (less than 0.01%): Hypothermia
• Frequency not reported: Drug withdrawal syndrome
• Uncommon (0.1% to 1%): Subdural hemorrhage, accidental injury, weight loss^[Ref]

Ocular

• Common (1% to 10%): Nystagmus, visual impairment, accommodation disorder, blurred vision, double vision, amblyopia^[Ref]

Psychiatric

• Common (1% to 10%): Confusional state, hallucination, depression, insomnia, euphoric mood, nightmare, personality changes
• Uncommon (0.1% to 1%): Memory loss/impairment, suicidal ideation, attempted suicide
• Rare (less than 0.1%): Excitement^[Ref]

Renal

• Very rare (less than 0.01%): Kidney calculus^[Ref]

Respiratory

• Common (1% to 10%): Respiratory depression, hypoventilation, dyspnea, bradypnea, feeling of pressure in the chest^[Ref]

Further information

Baclofen 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