Cetirizine Safety in G6PD Deficiency
Cetirizine (Zyrtec) is safe to use in patients with Glucose-6-phosphate dehydrogenase (G6PD) deficiency as it is not among the medications known to cause hemolytic reactions in these patients.
Understanding G6PD Deficiency and Medication Risks
- G6PD deficiency is the most common enzymatic disorder of red blood cells, affecting approximately 400 million people worldwide 1
- G6PD-deficient patients lack the ability to protect red blood cells against oxidative stresses from certain drugs, metabolic conditions, infections, and fava beans 1
- The severity of G6PD deficiency varies based on genetic variant and ethnic background, with the Mediterranean variant typically causing more severe reactions than the African variant 2
Medications Contraindicated in G6PD Deficiency
- Only seven medications have solid evidence to prohibit their use in G6PD deficiency 3:
Cetirizine and G6PD Deficiency
- Cetirizine is not listed among medications that cause hemolysis in G6PD-deficient patients in any of the guidelines or research evidence 2, 4, 3
- A comprehensive review of medications and G6PD deficiency found no evidence to contraindicate the use of cetirizine in normal therapeutic doses to G6PD-deficient patients 3
- Recent real-world studies have shown that many medications previously thought to be risky have been prescribed safely to G6PD-deficient patients without causing hemolytic episodes 5
Clinical Considerations
- When treating G6PD-deficient patients, it's essential to monitor for signs of hemolysis, including jaundice, dark urine, fatigue, and pallor, especially when starting any new medication 2
- Screening for G6PD deficiency is recommended before starting therapy with known oxidant drugs in patients with predisposing racial or ethnic backgrounds (Mediterranean, African, Indian, or Southeast Asian descent) 4
- If a G6PD-deficient patient develops methemoglobinemia, ascorbic acid (vitamin C) is the treatment of choice rather than methylene blue 4
Practical Recommendations
- Cetirizine can be safely administered at standard doses to patients with G6PD deficiency 3
- For patients with severe G6PD deficiency and multiple comorbidities, consider monitoring for any unusual symptoms after initiating treatment, though this is not routinely necessary 2
- Avoid medications with established risk of hemolysis in G6PD deficiency (dapsone, methylene blue, nitrofurantoin, phenazopyridine, primaquine, rasburicase, and tolonium chloride) 3