What over-the-counter (OTC) medications should individuals with Glucose-6-phosphate dehydrogenase (G6PD) deficiency avoid?

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Last updated: September 23, 2025View editorial policy

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OTC Medications to Avoid in G6PD Deficiency

Individuals with G6PD deficiency should avoid aspirin, NSAIDs (like ibuprofen and naproxen), certain sulfa-containing medications, and methylene blue due to risk of hemolysis. 1

Understanding G6PD Deficiency and Medication Risks

G6PD deficiency is the most common enzymatic disorder of red blood cells, affecting approximately 400 million people worldwide 2. This genetic condition reduces the ability of red blood cells to protect themselves against oxidative damage, making patients vulnerable to hemolysis when exposed to certain medications, foods, or during infections.

High-Risk OTC Medications to Avoid

Definite High-Risk Medications:

  • Phenazopyridine (AZO urinary pain relief products) 1, 3
  • Methylene blue (found in some urinary antiseptics) 1, 3
  • Nitrofurantoin (some OTC urinary tract infection products) 1, 3

NSAIDs with Caution:

  • Aspirin/acetylsalicylic acid 4
  • Ibuprofen (Advil, Motrin) 4
  • Naproxen (Aleve)

Other OTC Medications to Use with Caution:

  • Sulfa-containing products (some topical antibiotics)
  • Vitamin K supplements (high doses)
  • Menthol-containing products (in high concentrations)

Safe OTC Alternatives

Safe Pain Relievers:

  • Acetaminophen/Paracetamol (Tylenol) 1
  • Codeine-based products (where available OTC) 2

Safe Antibiotics (when available OTC):

  • Penicillins 1
  • Cephalosporins 1
  • Macrolides 1
  • Tetracyclines (except in children <8 years) 1

Important Considerations

Severity of G6PD Deficiency Matters

The risk of hemolysis varies depending on the G6PD variant and severity of deficiency:

  • Mediterranean variant (B-) has higher risk of severe hemolysis 5
  • African variant (A-) typically has milder deficiency with lower risk 5

Recent Evidence on Medication Safety

Recent real-world evidence suggests that some medications previously thought to be high-risk may be safer than expected. A 2024 study found that several medications, including nitrofurantoin, ciprofloxacin, and sulfamethoxazole/cotrimoxazole, were prescribed to thousands of G6PD-deficient patients without causing major hemolysis 6.

Non-Medication Triggers

Be aware that fava beans are the most common trigger of hemolysis in G6PD-deficient individuals (71.8% of hospitalized cases in one study), while medications accounted for only 4.2% of severe hemolytic episodes 6, 4.

Monitoring for Hemolysis

Watch for signs of hemolysis after taking any new medication:

  • Dark or tea-colored urine
  • Fatigue or weakness
  • Pallor
  • Jaundice (yellowing of skin/eyes)
  • Back or abdominal pain

If these symptoms occur, discontinue the medication immediately and seek medical attention 1, 2.

Practical Recommendations

  1. Always inform healthcare providers about G6PD deficiency before taking any new medication
  2. Carry medical identification indicating G6PD deficiency
  3. When in doubt about a medication's safety, consult with a healthcare provider
  4. Be particularly cautious during infections, as they can trigger hemolysis independently or worsen medication-induced hemolysis 1
  5. Maintain adequate hydration, especially during illness or when taking medications 1

By following these guidelines and avoiding high-risk medications, individuals with G6PD deficiency can significantly reduce their risk of hemolytic episodes while still having access to effective OTC treatment options.

References

Guideline

Management of G6PD Deficiency

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Study of Glucose-6-Phosphate Dehydrogenase Deficiency: 5 Years Retrospective Egyptian Study.

Endocrine, metabolic & immune disorders drug targets, 2018

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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