Hydroxychloroquine

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An event is serious (based on the ICH definition) when the patient outcome is:

• * death

• * life-threatening

• * hospitalisation

• * disability

• * congenital anomaly

• * other medically important event

A 64-year-old man developed haemolysis following off-label therapy with hydroxychloroquine for COVID-19 pneumonia.

The man, who had multiple morbidities, presented to hospital with cough and fever. Subsequent analyses led to the diagnosis of COVID-19 pneumonia. Therefore, he started receiving off-label therapy with hydroxychloroquine 400mg twice a day for 1 day, followed by 400mg daily for 9 days [route not stated], azithromycin, ceftriaxone, lopinavir/ritonavir and oseltamivir. His home medications were resumed. However, during hospital stay, he exhibited a drop in Hb level. Blood tests revealed the following: Hb 11.3 g/dL and retics count of 119 × 10 ³ [unit not stated], with normal WBC and platelet counts. Peripheral smear revealed moderate normochromic, normocytic anaemia with few ovalocytes, few hypochromic RBCs, few spherocytes and mild rouleaux formation with mild neutrophilic leucocytosis. Mild absolute lymphopenia was noted. Other laboratory analyses were significant for: total bilirubin 41 µmol/L, direct bilirubin 19.6 µmol/L, LDH 352 U/L and G6PD 14 [unit not stated] with normal folate and vitamin-B12 levels and elevated levels of ferritin. Hence, he was diagnosed with haemolysis secondary to G6PD deficiency. After ruling out all possible aetiologies for the drop in Hb, the haemolysis was attributed to the treatment with hydroxychloroquine [time to reaction onset not stated]. However, since the bleeding was minimal, and also because of the beneficial effects of hydroxychloroquine, he continued the treatment to complete the 10-day course, as scheduled. During this time, his Hb levels continued to decrease; however, improvement was noted following completion of the course.