Encephalopathy of Unknown Origin in a Baclofen Patient: Case Report and Review of the Literature

Neurological adverse events associated with baclofen: A disproportionality analysis based on FDA Adverse Event Reporting System

Purpose

Baclofen is a muscle relaxant that could carry the risk for neurological adverse events (nAEs). We aim to analyze the nAE profile of frequently used baclofen for its clinical application.

Methods

Our research is a disproportional analysis based on the FDA Adverse Event Reporting System (FAERS) database. We obtained adverse event reports of baclofen from January 2004 to June 2023 from the FAERS database. Reporting odds ratio (ROR) and Bayesian confidence propagation neural network (BCPNN) were performed to find nAE associated with baclofen.

Results

We extracted a total of 9305 nAE cases with baclofen as the primary suspect. The patients were mostly under 18 years old (45.49%), with markedly more males (43.72%) than females (36.52%). In all, 7275 (78.18%) reports were from the United States. There were 2023 of 9305 (21.74%) reports that occurred serious adverse events (SAE). The median onset time of reports with baclofen-related nAE was 10 days (interquartile range (IQR) 1-112). Intrathecal injection (75.78%) was more than oral (23.06%). We detected 119 significant signals, among which the higher frequencies were somnolence (ROR: 4.69, 95% CI (4.37, 5.03); IC: 2.17, IC025 (2.06)), tremor (ROR: 2.76, 95% CI (2.50, 3.04); IC: 1.43, IC025 (1.29)), lethargy (ROR: 6.37, 95% CI (5.71, 7.10); IC: 2.61, IC025 (2.45)), status epilepticus (ROR: 8.71, 95% CI (7.07, 10.73); IC: 2.98, IC025 (2.69)), generalized tonic-clonic seizure (ROR: 3.17, 95% CI (2.54,3.95); IC: 1.62, IC025 (1.30)], and cerebrospinal fluid leakage (ROR: 229.56, 95% CI (197.76, 266.47); IC: 6.61, IC025 (6.43)]. Unexpected significant nAE might also occur, such as intracranial hypotension (ROR: 428.52, 95% CI (355.18, 517.00); IC: 6.75, IC025 (6.56)], cognitive disorder (ROR: 2.65, 95% CI (2.21, 3.19); IC: 1.38, IC025 (1.11)], anterograde amnesia (ROR: 7.35, 95% CI (2.74, 19.72); IC: 1.69, IC025 (0.90)], metabolic encephalopathy (ROR: 14.77, 95% CI (10.40, 21.00); IC: 3.55, IC025 (2.93)], and myoclonus (ROR: 5.98, 95% CI (4.70, 7.59); IC: 2.46, IC025 (2.13)].

Conclusion

Given the wide use of baclofen, clinicians should be well-informed about important potential nAE. Although disproportional analysis is a refinement approach, it is still necessary to be vigilant about the nAE of baclofen. It is extremely crucial to early monitoring, especially in minors and the initial stage following the commencement of use.

Low-Dose Baclofen-Induced Encephalopathy in a Healthy Young Adult: Is Baclofen Toxicity Dose-Dependent?

Baclofen is a commonly used medication for managing muscle spasticity with the potential of causing life-threatening adverse effects, including encephalopathy as well as withdrawal symptoms including confusion and hallucinations following abrupt discontinuation. Severe toxicity with baclofen is common in patients with kidney disease, hence the importance of dose reduction and monitoring in patients with renal impairment. This article reports a case of encephalopathy with low-dose baclofen in an otherwise healthy young adult concurrently taking ibuprofen and baclofen and aims to underscore the importance of potential drug interaction and patient education when initiating baclofen.

Classifying Device-Related Complications Associated With Intrathecal Baclofen Pumps: A MAUDE Study

BACKGROUND

Intrathecal baclofen (ITB) is an effective treatment for spasticity, and therapeutic levels may be optimized using surgically implanted pumps. Though these devices are effective, complications can pose significant challenges to patients, decreasing the therapeutic effect and potentially requiring reoperation. As such, it is critical that complications associated with ITB be effectively characterized.

METHODS

We queried the Manufacturer and User Facility Device Experience (MAUDE) database for cases reported during the past 3 years documenting adverse events specifically related to ITB pumps. We identified 1935 adverse events that were individually analyzed and categorized by type of complication.

RESULTS

Out of the 1935 unique adverse events identified from the MAUDE database, 25.7% were device-related complications (n = 497). Of those, 50.3% were catheter-specific (n = 250), 21.3% (n = 106) were pump-specific, and 28.3% (n = 141) were included, more generally, in catheter or device erosion.

CONCLUSIONS

The MAUDE database may be a useful resource for evaluating ITB pump complications across a larger data set. By characterizing the complications and providing values for their total occurrences, patients and physicians may have more realistic expectations for the outcomes and morbidity of this device.