Myths & facts about Hydroxychloroquine, a prevent drug for Coronavirus
The risk of toxicity is dependent on daily dose and duration of use. At recommended doses, the risk of toxicity up to 5 years is under 1% and up to 10 years is under 2%, but it rises to almost 20% after 20 years.
By Dr KK Aggarwal
Source: Rheumatologist who started using it in 1973
Hydroxychloroquine causes retinal toxicity
No. Retinal toxicity potentially causing irreversible retinopathy, is predominantly associated with high daily doses and a duration of >5 years of use of chloroquine or hydroxychloroquine in the treatment of rheumatic diseases.
This side effect is with long term use of chloroquine. With hydroxychloroquine it is only a caution only after years of use.
The risk of toxicity is dependent on daily dose and duration of use. At recommended doses, the risk of toxicity up to 5 years is under 1% and up to 10 years is under 2%, but it rises to almost 20% after 20 years. However, even after 20 years, a patient without toxicity has only a 4% risk of converting in the subsequent year. [Ophthalmology 123 (6), 1386-94 Jun 2016]
Hydroxychloroquine causes QT prolongation
Only if used with azithromycin it can cause QT prolongation.
It cannot be given for 60 plus age
No, there is no such evidence. All international travels have been taking once a week as malarial prophylaxis
It can cause haemolysis in G6PD deficiency
There is no evidence. Although the manufacturer’s labelling recommends chloroquine be used with caution in patients with G6PD deficiency due to a potential for haemolytic anemia, there is limited data to support this risk. Many experts consider chloroquine, when given in usual therapeutic doses to WHO Class II and III G6PD deficient patients, to probably be safe (Cappellini 2008; Glader 2017; Luzzatto 2016; Youngster 2010). Safety in Class I G6PD deficiency (i.e., severe form of the deficiency associated with chronic haemolytic anemia) is generally unknown (Glader 2017). In a trial conducted in West Africa involving 74 G6PD deficient patients (predominantly Class III deficiency), there were no cases of haemolysis reported following exposure to usual doses of chloroquine (Mandi 2005). In addition, the ACR Rheumatology guidelines do not mention the need to evaluate G6PD levels prior to initiation of therapy (Singh 2015).
It has many contraindications
No. Only contraindication is hypersensitivity to chloroquine, 4-aminoquinoline compounds, or any component of the formulation.
Hydroxy-chloroquine is contraindicated in children
No, it is not given for COVID in children as they have high chances of natural recovery
It is an OTC drug
No, it is a prescription drug and given only on the prescription of RMP
It can damage the kidneys
There is no evidence.
((The writer is President, CMAAO, HCFI and Past national President IMA))