Hydroxychloroquine, primarily known by its brand name Plaquenil, is a medication with its main use being the prevention and treatment of malaria in regions where chloroquine resistance hasn't rendered it ineffective. Beyond malaria, it is also utilized in treating rheumatoid arthritis, lupus, and porphyria cutanea tarda. The medication is administered orally, typically in the form of hydroxychloroquine sulfate.
1934: Discovery of Chloroquine
In 1934, Hans Andersag and his team at Bayer laboratories discovered chloroquine, a synthetic analog of quinine with anti-malarial properties.
1947: Chloroquine Introduced Clinically
Chloroquine was introduced into clinical practice in 1947 for the prophylactic treatment of malaria.
1949: First Synthesis of Hydroxychloroquine
The initial synthesis of hydroxychloroquine was revealed in a patent filed by Sterling Drug in 1949.
1955: Hydroxychloroquine Approved for Medical Use
In 1955, Hydroxychloroquine was approved for medical use in the United States.
2003: Novel Mechanism of Hydroxychloroquine Discovered
A new mechanism of action for hydroxychloroquine was uncovered in 2003, showing that it inhibits the stimulation of toll-like receptor 9 (TLR9) family receptors. TLRs are key players in the innate immune system, recognizing microbial products and triggering inflammatory responses.
2019: Hydroxychloroquine Studied for COVID-19 Treatment
In 2019, research on Hydroxychloroquine began to investigate its potential for preventing and treating COVID-19. However, clinical trials found it to be ineffective for this purpose and possibly associated with dangerous side effects.
March 2020: Initial Use of Hydroxychloroquine for COVID-19
Several countries began using chloroquine or hydroxychloroquine to treat hospitalized COVID-19 patients in March 2020, despite the lack of formal approval through clinical trials.
April 2020: FDA Cautions Against Hydroxychloroquine Use for COVID-19
The FDA issued a caution against using hydroxychloroquine for COVID-19 outside of hospitals or clinical trials on April 24, 2020, citing the risk of serious heart rhythm problems.
June 2020: Withdrawal of Hydroxychloroquine as COVID-19 Treatment
Hydroxychloroquine was withdrawn as a potential COVID-19 treatment in June 2020 after trials showed no benefit for hospitalized patients with severe illness.
June 2020: Emergency Use Authorization for Hydroxychloroquine Revoked
The FDA revoked the emergency use authorization for hydroxychloroquine in June 2020 due to its lack of effectiveness against COVID-19 and potential risks.
2021: Hydroxychloroquine Usage Statistics
In 2021, Hydroxychloroquine was listed as the 116th most commonly prescribed medication in the United States, with over 5 million prescriptions. It was also included in the World Health Organization's List of Essential Medicines.
2021: Hydroxychloroquine Recommended in India
In 2021, India included hydroxychloroquine in its recommended treatment for mild cases of COVID-19.
2024: Scientific Evidence Against Hydroxychloroquine for COVID-19
As of 2024, scientific evidence does not support the use of hydroxychloroquine, alone or with azithromycin, for treating COVID-19.