From the Guidelines
Yes, it is necessary to check Glucose-6-phosphate dehydrogenase (G6PD) levels before prescribing certain medications that can trigger hemolytic anemia in G6PD-deficient individuals, especially for medications like primaquine and chloroquine, as indicated in a recent study from 2024 1. Medications that commonly require G6PD screening include antimalarials (primaquine, chloroquine), antibiotics (sulfonamides, dapsone, nitrofurantoin), rasburicase, and certain analgesics like high-dose aspirin. Testing is particularly important in patients from regions with high G6PD deficiency prevalence, including parts of Africa, the Mediterranean, Middle East, and Southeast Asia, as noted in guidelines from 2014 1. G6PD deficiency affects approximately 400 million people worldwide, with varying prevalence by ethnicity, and the condition causes reduced ability to protect red blood cells from oxidative stress, leading to hemolysis when exposed to triggering medications. If a patient tests positive for G6PD deficiency, alternative medications should be selected when possible, and in emergency situations where no alternatives exist, careful monitoring for signs of hemolysis (jaundice, dark urine, fatigue, back/abdominal pain) is essential, as suggested in a study from 2024 1. Some key points to consider include:
- The risk of hemolysis in patients with G6PD deficiency, particularly with certain medications like primaquine and chloroquine
- The importance of measuring G6PD levels, especially in men of African, Asian, or Middle Eastern origin, before starting hydroxychloroquine, as mentioned in a recent guideline 1
- The potential for alternative medications or adjusted dosing regimens in patients with G6PD deficiency
- The need for careful monitoring and follow-up in patients with G6PD deficiency who are prescribed medications that may trigger hemolytic anemia.
From the FDA Drug Label
Due to the risk of hemolytic anemia in patients with G6PD deficiency, G6PD testing has to be performed before using primaquine. When the G6PD status is unknown and G6PD testing is not available, a decision to prescribe primaquine must be based on an assessment of the risks and benefits of using primaquine.
Yes, it is necessary to check G6PD levels before prescribing certain medications, such as primaquine, due to the risk of hemolytic anemia in patients with G6PD deficiency 2.
- G6PD testing must be performed before using primaquine.
- If G6PD testing is not available, a decision to prescribe primaquine must be based on an assessment of the risks and benefits.
From the Research
Importance of G6PD Testing
- G6PD testing is crucial before prescribing certain medications, such as primaquine, to avoid the risk of acute haemolytic anaemia in individuals with G6PD deficiency 3, 4, 5, 6, 7.
- The risk of haemolysis is higher in populations with a high prevalence of G6PD deficiency, and G6PD testing can help identify individuals who are at risk 5.
- G6PD deficiency is a common genetic disorder that affects approximately 400 million people worldwide, making it essential to consider G6PD status when prescribing certain medications 6.
Medications that Require G6PD Testing
- Certain medications, such as primaquine, dapsone, methylthioninium chloride (methylene blue), nitrofurantoin, phenazopyridine, rasburicase, and tolonium chloride (toluidine blue), should be avoided in individuals with G6PD deficiency or used with caution after G6PD testing 3, 6.
- Other medications may be safe to use in normal therapeutic doses in individuals with G6PD deficiency, but G6PD testing is still recommended to ensure safety 6.
Consequences of Not Testing for G6PD
- Failure to test for G6PD deficiency before prescribing certain medications can lead to severe haemolytic anaemia, which can be life-threatening 3, 4, 5.
- Iatrogenic haemolysis can occur when primaquine is prescribed to individuals with unknown G6PD status, highlighting the importance of G6PD testing before treatment 4.
- G6PD testing can help prevent haemolytic events and ensure safe treatment outcomes 5, 7.