Contraindications to Baclofen
Baclofen is absolutely contraindicated in patients with hypersensitivity to the medication. 1
Primary Contraindications
- Hypersensitivity to baclofen - The only absolute contraindication per FDA labeling 1
- Severe renal impairment - Baclofen is primarily excreted by the kidneys, and accumulation can lead to toxicity in patients with kidney dysfunction 2
- Seizure disorders - Baclofen may lower seizure threshold and can cause seizures upon withdrawal 3, 2
- Psychiatric disorders - May worsen confusion, psychosis, or schizophrenia 2
Relative Contraindications/Use with Caution
Neurological Conditions
- Stroke patients in recovery phase - Baclofen may impair motor learning and rehabilitation 4
- Patients with cognitive impairment - Increased risk of confusion and sedation 2
- Sleep-disordered breathing - May worsen oxygen saturation during sleep 5
Medical Conditions
- Hepatic impairment - Increased risk of CNS side effects 3
- Elderly patients - Higher risk of CNS depression, confusion, and falls 2
- History of substance abuse - Potential for dependence and withdrawal 3
- Pregnancy - Limited safety data; risk-benefit assessment needed 3
Special Considerations for Intrathecal Baclofen
Intrathecal baclofen has additional contraindications:
- Active infection - Increased risk of CNS infection
- Anatomical abnormalities preventing catheter placement
- Inability to attend follow-up for pump refills 6
Withdrawal Risk
Abrupt discontinuation of baclofen can lead to severe, potentially life-threatening withdrawal symptoms:
- Visual and auditory hallucinations
- Anxiety and agitation
- Delirium and seizures
- High fever and tachycardia
- Muscle rigidity potentially leading to rhabdomyolysis
- Multiorgan failure and death 3
This risk is particularly pronounced with intrathecal baclofen, where withdrawal can be life-threatening 3. Any plan to discontinue baclofen must include a slow, careful tapering schedule.
Clinical Decision-Making Algorithm
Assess for absolute contraindications:
- Known hypersensitivity to baclofen
- Severe renal impairment (eGFR <30mL/min/1.73m²)
Evaluate risk-benefit in patients with:
- Seizure disorders
- Psychiatric conditions
- Cognitive impairment
- Sleep apnea
- Hepatic dysfunction
- Advanced age
- Substance use disorders
For patients requiring baclofen despite relative contraindications:
- Start with lower doses
- Monitor more frequently
- Consider alternative agents (tizanidine, gabapentin, or topiramate)
- Ensure patient/caregiver education about risks
When discontinuing baclofen:
- Always taper gradually
- Monitor for withdrawal symptoms
- Have rescue medications available (benzodiazepines)
- Consider hospitalization for high-risk patients
Baclofen remains an important medication for spasticity management, but careful consideration of contraindications and appropriate monitoring can help minimize risks while maximizing therapeutic benefits.