UMEM Educational Pearls

Category: Neurology

Title: Neurological Adverse Reactions with Antimicrobials

Keywords: drug reaction, toxicity, neurotoxicity, antibiotics (PubMed Search)

Posted: 11/10/2021 by WanTsu Wendy Chang, MD (Emailed: 11/11/2021)
Click here to contact WanTsu Wendy Chang, MD

Antimicrobial medications can be associated with neurological adverse reactions.
An individual’s risk is influenced by their age, weight, nutritional status, the medications they are taking concurrently, and pharmacological properties (dosage, half-life, CNS permeability).
Encephalopathy
- Seen with beta-lactams, fluoroquinolones, clarithromycin, and sulfamethoxazole-trimethoprim.
- Most commonly with cefepime.
- Higher risk in elderly, renal dysfunction, and preexisting CNS disease.
Seizures
- Beta-lactams block GABA receptors.
- Highest risk with cefepime and imipenem.
Peripheral neuropathy
- Associated with metronidazole, fluoroquinolones, linezolid, chloramphenicol, and isoniazid.
- Most cases are dose dependent.
- Some cases are irreversible.
Ototoxicity
- Aminoglycosides cause cochlear NMDA receptor excitotoxicity.
Weakness
- Fluoroquinolones, macrolides, and aminoglycosides inhibit acetylcholine release and bind neuromuscular junction receptors.
- Should be avoided in myasthenia gravis and Lambert-Eaton syndrome.
Movement disorders
- Tremors – sulfamethoxazole-trimethoprim
- Dyskinesia, dystonic reactions – fluoroquinolones, chloramphenicol
- Cerebellar syndrome – metronidazole, aminoglycosides

Bottom Line: Recognition of antibiotic associated neurotoxicity reduces unnecessary workup and serious adverse effects.

Vo ML. Commonly used drugs for medical illness and the nervous system. Continuum (Minneap Minn) 2020;26(3, Neurology of Systemic Disease):716-731.

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