Serious Potential Adverse Effects of Chloroquine and Hydroxychloroquine for Treating COVID-19

Man Suffering Heart Arrhythmia

Cardiac arrhythmias are a potential side effect of chloroquine and hydroxychloroquine.

Chloroquine, hydroxychloroquine, and azithromycin are being used to treat and prevent COVID-19 despite weak evidence for effectiveness, and physicians and patients should be aware of the drugs’ potentially serious adverse events, states a review in CMAJ (Canadian Medical Association Journal).

“Physicians and patients should be aware of several rare but potentially life-threatening adverse effects of chloroquine and hydroxychloroquine,” says Dr. David Juurlink, Division of Clinical Pharmacology and Toxicology, Sunnybrook Health Sciences Centre, and a senior scientist at ICES.

The review provides an overview of potential harms associated with these drugs as well as their management based on the best available evidence.

Potential adverse effects include

  • Cardiac arrhythmias
  • Hypoglycemia
  • Neuropsychiatric effects, such as agitation, confusion, hallucinations and paranoia
  • Interactions with other drugs
  • Metabolic variability (some people metabolize chloroquine and hydroxychloroquine poorly and a small percentage metabolize them rapidly, which affects the response to treatment)
  • Overdose (chloroquine and hydroxychloroquine are highly toxic in overdose and can cause seizures, coma and cardiac arrest)
  • Drug shortages (patients with autoimmune disorders such as rheumatoid arthritis, lupus and other chronic diseases, who take hydroxychloroquine to treat these conditions could have problems accessing this drug)

The review summarizes the poor quality of evidence suggesting that these treatments might be beneficial in patients with COVID-19 and cautions that it is possible that these treatments could worsen the disease.

“Despite optimism (in some, even enthusiasm) for the potential of chloroquine or hydroxychloroquine in the treatment of COVID-19, little consideration has been given to the possibility that the drugs might negatively influence the course of disease,” says Dr. Juurlink. “This is why we need a better evidence base before routinely using these drugs to treat patients with COVID-19.”

Reference: “Safety considerations with chloroquine, hydroxychloroquine and azithromycin in the management of SARS-CoV-2 infection” by David N. Juurlink MD PhD, 8 April 2020, CMAJ.
DOI: 10.1503/cmaj.200528

3 Comments on "Serious Potential Adverse Effects of Chloroquine and Hydroxychloroquine for Treating COVID-19"

  1. Millions of travelers to S.America and Africa have taken Chloroquine and Hydroxychloroquine to ward off Malaria without any issues whatsoever. One nutsack took maximum doses for 2 straight years daily and had retinal issues with their vision instead of merely using a mosquito net and some deet now and then. Covid-19 treatment is typically 6 days, 12 tabs at 200mg each. Very limited use. This drug is cheap and generic at $8 a full treatment which is the issue not the bogus adverse effects claim.

  2. azithromycin has been known to have heart related risks and other cautions.

  3. gernald mcnaughton | January 21, 2023 at 8:29 am | Reply


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