Baclofen Should Be Continued on the Day of Surgery
Yes, baclofen should be taken preoperatively including on the day of operation. 1 This recommendation is driven by the serious risk of life-threatening withdrawal symptoms that outweigh concerns about perioperative sedation.
Rationale for Continuation
Critical Withdrawal Risk
The primary reason to continue baclofen is the significant morbidity and mortality risk associated with abrupt discontinuation 1:
- Withdrawal symptoms include visual and auditory hallucinations, anxiety, agitation, delirium, fever, tremors, tachycardia, and seizures 1
- These symptoms can occur within hours to days after discontinuation 2
- Intrathecal baclofen withdrawal is potentially life-threatening, with high fever, altered mental status, rebound spasticity, and muscle rigidity leading to rhabdomyolysis, multiorgan failure, and death 1
Clinical Evidence
Historical case reports demonstrate that patients who had baclofen discontinued preoperatively developed hallucinations postoperatively, which resolved only after reinstituting the medication at 23 and 31 hours 2. This underscores that if possible, patients should be withdrawn slowly from baclofen before surgery, but if withdrawn abruptly, should be restarted as soon as possible 2.
Special Considerations
Intrathecal Baclofen
Perioperative management of patients receiving intrathecal baclofen should be planned with input from a specialist 1. The anesthesiologist must be prepared to avoid intraoperative interruption of baclofen delivery before starting spinal surgery and recognize withdrawal symptoms in the immediate postoperative period 3.
Drug Interactions and Side Effects
While baclofen should be continued, be aware of:
- Additive CNS depression when combined with opioids, benzodiazepines, general anesthetics, and other CNS depressants 4
- Synergistic CNS depression can occur with pregabalin, particularly in patients with renal impairment 5
- Increased delirium risk in older adults (>65 years) undergoing lumbar fusion when baclofen is used postoperatively, with a 2.00 times higher risk compared to controls 6
Renal Impairment
Baclofen should be given with caution in patients with impaired renal function, as it is primarily excreted unchanged through the kidneys, and dosage reduction may be necessary 4. Heightened caution is warranted when combining with other medications in this population 5.
Common Pitfalls to Avoid
Do not discontinue baclofen abruptly as part of routine preoperative procedures—this historical practice led to preventable complications 2
Do not assume oral baclofen can be safely held even for short procedures—withdrawal can begin within hours 2
In elderly patients undergoing spine surgery, use baclofen postoperatively with caution given the doubled delirium risk, but do not discontinue preoperative therapy 6
Ensure pump function is maintained during positioning and throughout surgery for patients with intrathecal systems 3
Adjust expectations for postoperative sedation—patients may require closer monitoring due to additive CNS depressant effects with anesthetic agents 4