Baclofen

A case report documents central sleep apnea at a baclofen dose of 10 mg, indicating respiratory risk even at standard therapeutic doses in susceptible individuals with pre-existing sleep-disordered breathing.

Seizures occur paradoxically during both acute baclofen intoxication and withdrawal. Patients with pre-existing seizure disorders may be at increased risk, though controlled studies isolating baclofen as an independent seizure risk factor are lacking.

Depression and suicidal ideation have been reported in post-marketing surveillance of baclofen, particularly in AUD populations. Causal attribution is complicated by high baseline psychiatric comorbidity in these populations. No controlled studies have isolated baclofen as an independent risk factor.

Baclofen accumulates rapidly in patients with eGFR <30 mL/min/1.73 m² due to renal-dominant elimination. Encephalopathy and coma have been documented at standard therapeutic doses in this population. A single standard dose has precipitated encephalopathy in a peritoneal dialysis patient.

Patients with moderate renal impairment require dose reduction and close monitoring. Apparent renal clearance approximates creatinine clearance, making CrCl a practical proxy for dose adjustment.

A comparative study of 134 women exposed to baclofen in early pregnancy versus 400 controls demonstrated increased risk of major malformations. Neonatal withdrawal syndrome including seizures and autonomic instability has been documented in infants exposed in utero.

Concurrent consumption of baclofen with significant alcohol intake produces synergistic sedation and respiratory depression that can be lethal. Paradoxically, baclofen is used clinically to treat alcohol craving — but active co-ingestion is life-threatening.

GHB is an endogenous GABA-B agonist. Combination with baclofen produces near-additive receptor activation with synergistic CNS and respiratory depression. Classified as lethal interaction.

As a prodrug of GHB, GBL produces the same near-additive GABA-B activation and synergistic CNS depression when combined with baclofen. Classified as lethal interaction.

Opioids combined with baclofen produce potentially lethal CNS and respiratory depression through independent but additive mechanisms. Case series document life-threatening episodes with intrathecal baclofen combined with opioid analgesics.

Beyond simple additive CNS depression, benzodiazepines specifically exacerbate baclofen neurotoxicity, producing a metabolic encephalopathy with EEG-confirmed changes distinct from sedative summation. This represents a genuine potentiation risk.

Methaqualone combined with baclofen produces additive-to-synergistic CNS depression through complementary GABAergic mechanisms. Classified as lethal interaction.