Chloroquine and hydroxychloroquine: what to know about the potential coronavirus drugs

Loss of smell and taste could be symptoms of the novel coronavirus, according to ENT UK, a professional organization representing ear, nose and throat surgeons in the United Kingdom. CNN's Dr. Sanjay Gupta explains.

Posted: Mar 24, 2020 2:41 AM
Updated: Mar 24, 2020 2:41 AM

As the world's heath experts race to find treatments -- and eventually, a cure -- for the novel coronavirus, two drugs have jumped to the front of the conversation: chloroquine and hydroxychloroquine.

President Donald Trump has called the drugs, which are used to treat malaria and other conditions, game changers, and a rush to procure the pharmaceuticals spurred several US states to take measures to prevent shortages amid the Covid-19 pandemic.

Your coronavirus questions answered

New York moved to begin trials Tuesday, procuring 70,000 doses of hydroxychloroquine and 750,000 doses of chloroquine, Gov. Andrew Cuomo said. In addition Bayer, the drug maker, has donated 3 million doses of Resochin, its brand name for chloroquine, to the federal government.

Perhaps demonstrating why health officials are urging caution -- saying chloroquine requires further clinical study and might not be the panacea it's billed to be -- officials in Nigeria's Lagos state have reported three overdoses in the days since the drug entered the conversation surrounding the pandemic.

So, what exactly are these drugs, and what promise do they hold?

Vital to battle against malaria

Chloroquine is used to treat malaria, as well as in chemoprophylaxis, which is the administering of drugs to prevent the development of disease, according to the US Centers for Disease Control and Prevention. Since 2006, it has not been recommended for use in severe malaria because of problems with resistance, particularly in the Oceania region, according to the World Health Organization.

WHO includes it on its list of "essential medicines," meaning it should be kept affordable and accessible at all times.

According to the Swiss-registered organization, Medicines for Malaria Venture, chloroquine is a derivative of quinine, which French chemists in 1820 isolated from the bark of the cinchona tree found in South America, employing it as a treatment for fevers.

German scientists created the synthetic chloroquine in 1934 as part of a class of anti-malarials, MMV said, and chloroquine and DDT became "the two principal weapons in WHO's global eradication malaria campaign" following World War II, the organization said.

Hydroxychloroquine is what's known as an analog of chloroquine, meaning the two have similar structures but different chemical and biological properties. The former is considered the less toxic derivative, according to studies.

It's given to patients with rheumatoid arthritis, lupus and the blood disorder porphyria cutanea tarda, the CDC said.

'It's not going to kill anybody'

The reason Trump lauds the drugs is because they've been shown, in labs, to be effective against severe acute respiratory syndrome coronaviruses -- including the SARS strain that causes Covid-19 -- as well as other coronaviruses, the CDC said.

Hydroxychloroquine is being studied to determine if it can prevent the onset of Covid-19 before or after a patient is infected with the SARS coronavirus strain that causes it, and if it can be used to treat Covid-19 sufferers, the CDC said.

Because the drug has been in use for years, Trump said, it potentially poses fewer risks than a newly developed drug.

"The nice part is," he said last week, "it's been around for a long time, so we know that if things don't go as planned, it's not going to kill anybody."

The CDC cited a study, documented in the journal Bioscience Trends this month, that chloroquine phosphate has demonstrated "apparent efficacy and acceptable safety against COVID-19-associated pneumonia" in trials in China.

It is thus considered a recommended antiviral for Covid-19 treatment in China, and several countries are recommending both drugs for hospitalized Covid-19 patients, the CDC said.

Chloroquine also appears to have "broad-spectrum antiviral properties" and effects on immune response, Bayer said in its statement announcing the drug donations.

"New data from initial preclinical and evolving clinical research conducted in China, while limited, shows potential for the use of Resochin in treating patients with COVID-19 infection," the statement said.

Evidence only anecdotal, expert said

Regarding the combination of hydroxychloroquine and the antibiotic azithromycin -- which Trump tweeted could be "one of the biggest game changers in the history of medicine" -- a single "small study" shows the combination helped against the SARS strain that causes Covid-19, the CDC said, but "did not assess clinical benefits."

The CDC said the combination can disrupt the heart's electrical activity and warns against prescribing the paired drugs to anyone with chronic medical conditions, such as renal failure or hepatic disease.

Chloroquine's side effects include seizures, nausea, vomiting, deafness, vision changes and low blood pressure. Both chloroquine and hydroxychloroquine, however, are reportedly well-tolerated in Covid-19 patients, according to the CDC.

All that said, Dr. Anthony Fauci, the director of National Institute of Allergy and Infectious Diseases who has appeared alongside Trump at several news conferences, has said evidence of the drugs' effectiveness is only anecdotal.

With respect to the SARS strain, the drugs' effectiveness was never vetted in a clinical trial, he said.

The drugs may be effective against the novel coronavirus, Fauci said, but more data is needed to "show it is truly safe and effective under the conditions of Covid-19."

For these reasons, the US Food and Drug Administration has not approved the drugs for coronavirus treatment, despite Trump claiming Thursday the agency had done so.

'It showed promise in the test tubes'

In a Thursday statement, the FDA said it had been working with government agencies and universities to learn whether chloroquine can reduce symptoms and stem the spread of Covid-19 in those with mild to moderate cases of the virus.

"We also must ensure these products are effective; otherwise we risk treating patients with a product that might not work when they could have pursued other, more appropriate treatments," FDA Commissioner Stephen Hahn said in the statement.

During a meeting of the coronavirus task force, Hahn called for "a large, pragmatic clinical trial to actually gather that information and answer the question that needs to be answered -- asked and answered."

The FDA is also talking with drug manufacturers about ramping up production of the drugs to handle a spike in demand and to ensure that people with life-threatening conditions such as lupus can still obtain it.

Dr. Deborah Birx, Vice President Mike Pence's coronavirus response coordinator and another regular at Trump's news conferences, said in a Fox News interview last week that people should not confuse the drugs showing "promise" in other countries with actual efficacy.

"That doesn't mean that it will show promise in Americans," she told the news outlet. "It showed promise in the test tubes. We are very interested in making sure we have eliminated red tape to make the drug available through their physicians, and study it at the same time. At the same time, we are doing clinical trials on other products we think also will show promise."

One drug, lopinavir-ritonavir, did not show promise for treating Covid-19-related pneumonia in China, the CDC said. Another medication mentioned by Trump, remdesivir, has "broad antiviral activity," the CDC said, but requires further study.

Indiana Coronavirus Cases

Data is updated nightly.

Confirmed Cases: 47432

Reported Deaths: 2687
CountyConfirmedDeaths
Marion11546683
Lake5104242
Elkhart321144
Allen2737129
St. Joseph190866
Cass16389
Hamilton1538100
Hendricks1390100
Johnson1256118
Porter72037
Tippecanoe6948
Madison65564
Clark64044
Bartholomew58244
Howard56557
LaPorte56326
Kosciusko5354
Vanderburgh5026
Marshall4823
Jackson4693
Noble46928
LaGrange4677
Hancock44035
Boone43743
Delaware43150
Shelby42325
Floyd37144
Morgan32731
Montgomery29320
Grant29126
Clinton2882
Monroe27628
Dubois2666
White26010
Henry25815
Decatur24932
Lawrence24225
Vigo2318
Dearborn22823
Harrison21222
Warrick21229
Greene18532
Miami1822
Jennings17411
Putnam1688
DeKalb1604
Scott1607
Daviess14216
Orange13623
Wayne1366
Steuben1282
Perry1279
Franklin1248
Ripley1157
Jasper1142
Wabash1122
Carroll1102
Fayette987
Newton9810
Starke923
Whitley905
Randolph784
Huntington742
Jefferson722
Wells711
Fulton691
Jay680
Washington681
Gibson672
Knox640
Pulaski641
Clay604
Rush563
Adams501
Benton480
Owen471
Sullivan441
Brown381
Posey380
Blackford372
Spencer371
Crawford300
Fountain302
Tipton301
Switzerland260
Martin220
Parke220
Ohio140
Vermillion140
Warren141
Union130
Pike100
Unassigned0193

Ohio Coronavirus Cases

Data is updated nightly.

Confirmed Cases: 56183

Reported Deaths: 2907
CountyConfirmedDeaths
Franklin10023420
Cuyahoga7571372
Hamilton5770197
Marion273038
Lucas2700302
Pickaway218841
Summit2110206
Montgomery193126
Mahoning1818231
Butler154744
Columbiana129560
Stark1091112
Lorain99767
Trumbull92565
Warren82321
Clark7659
Delaware55315
Belmont54422
Fairfield54316
Tuscarawas54110
Medina50832
Lake49218
Licking46612
Miami45531
Portage43258
Ashtabula43144
Wood41251
Geauga40042
Clermont3946
Wayne36051
Richland3325
Allen30840
Mercer2808
Greene2489
Darke24625
Erie23622
Holmes2263
Huron2112
Madison1938
Ottawa14323
Crawford1355
Washington13120
Putnam12715
Sandusky12714
Hardin12012
Ross1183
Morrow1161
Auglaize1064
Coshocton942
Monroe8817
Jefferson872
Union821
Muskingum811
Hancock781
Hocking788
Preble731
Williams692
Clinton680
Guernsey683
Lawrence680
Shelby654
Fulton610
Ashland581
Carroll583
Logan581
Wyandot586
Brown561
Defiance503
Athens491
Knox481
Fayette460
Highland441
Champaign391
Scioto380
Van Wert340
Seneca332
Perry321
Henry290
Adams231
Paulding230
Pike230
Jackson220
Vinton222
Gallia161
Harrison121
Meigs120
Morgan110
Noble110
Unassigned00
Fort Wayne
Clear
72° wxIcon
Hi: 92° Lo: 68°
Feels Like: 72°
Angola
Clear
64° wxIcon
Hi: 90° Lo: 68°
Feels Like: 64°
Huntington
Overcast
67° wxIcon
Hi: 90° Lo: 68°
Feels Like: 67°
Decatur
Clear
66° wxIcon
Hi: 92° Lo: 69°
Feels Like: 66°
Van Wert
Clear
66° wxIcon
Hi: 92° Lo: 68°
Feels Like: 66°
More Heat & Humidity Sunday
WFFT Radar
WFFT Temperatures
WFFT National

Community Events