Bromide intoxication secondary to pyridostigmine bromide therapy

Area of Science:

• Clinical Toxicology
• Neuropharmacology

Background:

• Bromide intoxication can be challenging to diagnose, often presenting with a low or negative anion gap due to bromide being misidentified as chloride in standard laboratory tests.
• Myasthenia gravis is a chronic autoimmune neuromuscular disease that impairs communication between nerves and muscles.

Observation:

• A 59-year-old woman with myasthenia gravis developed postoperative psychosis after receiving a large dose of pyridostigmine bromide.
• The patient's condition initially suggested bromide intoxication due to a negative anion gap observed in laboratory results.

Findings:

• The diagnosis of bromide intoxication was confirmed by direct measurement of serum bromide levels.
• This case represents the first reported instance of bromide intoxication specifically linked to the administration of pyridostigmine bromide.

Implications:

• This case underscores the importance of considering bromide intoxication in patients presenting with altered mental status and a negative anion gap, especially those on medications containing bromide.
• Clinicians should be aware of pyridostigmine bromide as a potential source of bromide intoxication, prompting direct serum bromide level measurement for definitive diagnosis.