Cetirizine is Safe for G6PD Deficiency
Cetirizine can be used safely in patients with G6PD deficiency, as antihistamines are not among the medications known to cause hemolysis in these patients.
Evidence-Based Medication Safety in G6PD Deficiency
The most comprehensive evidence identifies only seven medications that are definitively contraindicated in G6PD deficiency 1, 2:
- Dapsone
- Methylthioninium chloride (methylene blue)
- Primaquine
- Rasburicase
- Nitrofurantoin
- Phenazopyridine
- Tolonium chloride (toluidine blue)
Cetirizine, as an antihistamine, does not appear on this list and has no documented evidence of causing hemolysis in G6PD-deficient patients 2.
Why Many Medications Are Wrongly Suspected
A critical insight from the literature is that many compounds have been incorrectly cited as causing hemolysis because they were administered during infection-related hemolytic episodes, not because the medication itself triggered hemolysis 2. This historical confusion has led to unnecessarily restrictive medication lists that cause patient distress and limit treatment options.
Real-World Safety Data
A large real-world study of 31,962 G6PD-deficient patients found that only 71 cases (0.2%) experienced major hemolysis requiring hospitalization over 13 years 3:
- 71.8% were caused by fava beans 3
- 8.5% were associated with infections 3
- Only 4.2% (3 cases) were potentially medication-related, involving nitrofurantoin, phenazopyridine, and an unspecified "pain killer" 3
This study demonstrated that hundreds to thousands of G6PD-deficient patients safely used medications previously suspected as risky, including various antibiotics and other agents 3.
Clinical Monitoring Considerations
While cetirizine is safe, when starting any new medication in G6PD-deficient patients, monitor for signs of hemolysis 4, 1:
- Jaundice
- Dark urine
- Fatigue
- Pallor
The severity of potential reactions varies by genetic variant, with Mediterranean variants (Gdmed) causing more severe reactions than African variants (GdA-) 5, 4.