Hydroxychloroquine as marketed in Europe
A young doctor in an intensive care unit (ICU) in New York made an important observation.

He experienced several patients that did not show any typical symptoms of pneumonia but nevertheless they were extremely breathless (dyspnoeic) and cyanotic (blue skin). "They were not Covid-19 patients; they looked like passengers of an airplane at high-altitude losing pressure."

My warning follows my following observations:

Chloroquine and high-dose intravenous vitamin-C are known to damage the function of erythrocytes in case of a lack of Glucose-6-phosphat-Dehydrogenase (Favism), which is the most frequent enzyme-defect worldwide.

It is inherited and the responsible genes are located on the X-chromosome.

As women have two X-chromosomes, one of them might be ok and therefore they are less vulnerable.

Men only have one X-chromosome and are endangered if this carries the defect.

Most of the carriers of this genetic defect are found in countries where malaria is or used to be endemic.

This is why citizens with ancestors from such regions are at risk to suffer from a lack of oxygen and dyspnoea when taking chloroquine derivatives or high-dose intravenous vitamin-C.

It is likely that this effect is more frequent in countries with higher prevalence of favism and in regions with many migrants from those countries.

Therefore I urge the responsible agencies to examine this problem and to provide all medical units with adequate information.