[Unwanted side effects of antibacterials--a diagnostic challenge]

Area of Science:

• Pharmacology
• Clinical Medicine
• Toxicology

Background:

• Antibacterial agents are crucial for treating infections.
• However, like all medications, they can cause adverse drug reactions.
• Rare side effects may be overlooked, especially when outside a physician's primary specialty.

Observation:

• Case 1: A 57-year-old female developed interstitial lung fibrosis attributed to nitrofurantoin after a year of use for urinary tract infections, leading to fatal respiratory failure.
• Case 2: A 20-year-old male experienced severe headache and psychomotor deceleration, suspected to be pseudotumor cerebri, a rare side effect of minocycline for acne, which resolved after drug discontinuation.
• Case 3: An 82-year-old female developed confusion and dementia during a week of moxifloxacin treatment for pneumonia, with symptoms persisting for over two months post-treatment.

Findings:

• Nitrofurantoin can cause severe pulmonary toxicity.
• Minocycline is associated with rare neurological side effects like pseudotumor cerebri.
• Fluoroquinolones, such as moxifloxacin, may lead to prolonged cognitive impairment.

Implications:

• Physicians must maintain a high index of suspicion for rare adverse drug effects, even when symptoms fall outside their specialty.
• Prompt identification and discontinuation of the offending agent are critical for patient outcomes.
• Awareness of these rare toxicities is essential for safe antibacterial prescribing practices.