Which medications are contraindicated in Guillain‑Barré syndrome and what are the recommended safe alternatives?

Drug Contraindications in Guillain-Barré Syndrome

Avoid β-blockers, intravenous magnesium, fluoroquinolones, aminoglycosides, and macrolides in all patients with Guillain-Barré syndrome, as these medications worsen neuromuscular function and can exacerbate weakness. 1, 2

Medications That Must Be Avoided

Neuromuscular Transmission Blockers

• β-blockers are contraindicated because they impair neuromuscular transmission and can worsen the already compromised motor function in GBS patients 1, 2
• Intravenous magnesium must be avoided as it blocks neuromuscular transmission at the presynaptic level, potentially precipitating or worsening respiratory failure 1, 2

Antibiotics That Worsen Neuromuscular Function

• Fluoroquinolones (e.g., ciprofloxacin, levofloxacin) are contraindicated because they interfere with neuromuscular transmission and can cause peripheral neuropathy 1, 2
• Aminoglycosides (e.g., gentamicin, tobramycin) block acetylcholine release at the neuromuscular junction and must be avoided 1, 2
• Macrolides (e.g., azithromycin, erythromycin) can worsen neuromuscular function and should not be used 1, 3

Safe Alternatives for Common Clinical Scenarios

For Infections Requiring Antibiotics

• Use penicillins (amoxicillin with or without clavulanic acid) as first-line agents when bacterial infection is suspected or documented 4
• Cephalosporins are safe alternatives that do not impair neuromuscular transmission 1
• Start appropriate antimicrobials concurrently with immunotherapy (IVIg or plasma exchange) if active infection is documented—do not delay GBS treatment while attempting to rule out infection 1

For Cardiovascular Management

• Avoid β-blockers for blood pressure or heart rate control; instead, use short-acting agents that can be titrated rapidly in the ICU setting for autonomic instability 1, 2
• Continuous cardiac monitoring is essential, as dysautonomia occurs frequently and requires careful management without β-blockade 5, 1

For Pain Management

• Gabapentin or pregabalin are the preferred first-line agents for neuropathic pain and paresthesias 5, 1
• Duloxetine is an effective alternative for neuropathic pain management 5, 1
• Avoid opioids for pain management, as they do not effectively treat neuropathic pain and increase risks of constipation and respiratory depression 5, 1
• Gabapentinoids can be started immediately alongside IVIg without drug interactions 2

Medications to Use With Extreme Caution

Corticosteroids

• Do not use corticosteroids alone for idiopathic GBS, as randomized trials show no benefit and oral corticosteroids may worsen outcomes 1, 6, 7
• Corticosteroids are only appropriate in the specific context of immune checkpoint inhibitor-related GBS, where methylprednisolone 2-4 mg/kg/day is added concurrently with IVIg or plasma exchange 5, 1

Statins

• Discontinue statins if creatine kinase is elevated, as they can contribute to muscle damage and rhabdomyolysis risk in patients with severe muscle involvement 2

Critical Clinical Pitfalls

Infection Management

• The presence of active infection is not a contraindication to starting IVIg or plasma exchange 1
• Preceding infections have usually resolved before GBS weakness begins (1-3 weeks after triggering infection) 1
• If infection is documented or highly suspected, start targeted antimicrobials (avoiding contraindicated antibiotics) concurrently with immunotherapy—never delay GBS treatment 1

Respiratory Compromise

• Medications that worsen neuromuscular function are particularly dangerous because approximately 20-25% of GBS patients develop respiratory failure requiring mechanical ventilation 1, 7
• Even seemingly stable patients can deteriorate rapidly, making avoidance of neuromuscular-blocking medications absolutely critical 1, 2

Autonomic Dysfunction

• Dysautonomia affects most GBS patients and includes blood pressure/heart rate instability, making β-blocker use especially hazardous 5, 1
• Autonomic complications contribute significantly to the 3-10% mortality rate in GBS 1, 2

Monitoring Requirements When Medications Are Necessary

• If antibiotics are required for documented infection, choose penicillins or cephalosporins and monitor closely for any worsening of neurological function 1, 4
• Serial neurological examinations should be performed daily to detect any medication-related deterioration 1, 2
• Respiratory function must be assessed frequently (vital capacity, negative inspiratory force) when any systemic medications are administered 1, 2