Why is it advised not to use parasite drugs?
While the U.S. Food and Drug Administration this week announced the full approval of Pfizer’s COVID-19 vaccine, some people are still turning to an anti-parasite drug that is not proven to treat the virus and could cause severe health problems.
The Houston Chronicle’s COVID-19 Help Desk is here to clear up any confusion about existing treatments for COVID, which is continuing to send people to the hospital in record numbers. Every week, a Chronicle reporter answers readers’ questions about how the virus works, what to expect with the vaccine updates and other concerns on Houstonians’ minds.
What is ivermectin, and why are officials saying not to use it to treat COVID-19?
Ivermectin is a medication used to treat certain parasitic infections. It is approved by the FDA to treat people with intestinal strongyloidiasis and onchocerciasis, two conditions caused by parasitic worms. It can also be used to treat head lice and skin conditions such as rosacea.
The over-the-counter version for animals is designed to prevent heartworm disease and certain internal and external parasites, according to the FDA.
In the early days of the pandemic, the drug showed some activity against the virus that causes COVID-19 in lab tests, said Dr. Luis Ostrosky, chief of infectious diseases with McGovern Medical School at UTHealth Houston. But there was a key problem with that finding.
“This activity only occurs when you add concentrations of it that are extremely toxic to humans,” said Ostrosky.
To this day, further testing has not shown any meaningful benefits from use of the drug at any stage of COVID-19, experts say. Taking the drug for any unapproved use can be dangerous. People can overdose, which may cause cause nausea, vomiting, diarrhea, hypotension, allergic reactions, dizziness, ataxia, seizures, coma and even death, according to the FDA.
The version of the drug designed for animals can also be harmful to humans. Animal drugs are often highly concentrated because they are intended for large animals like horses and cows. Additionally, many inactive ingredients found in animal products aren’t evaluated for use in people, according to the FDA.
People who take the animal product are ending up in emergency rooms, said Ostrosky. The drug has also triggered an uptick in calls to poison control departments in both Texas and Mississippi, according to media reports.
What does the FDA’s full approval of the Pfizer vaccine mean?
The FDA on Monday announced the full approval of the Pfizer vaccine for those 16 and older. That means the vaccine has now undergone extensive review over a substantial period of time —more than six months —to ensure long-term safety, said Dr. Prathit Kulkarni, an assistant professor of medicine in infectious diseases a Baylor College of Medicine.
A fully approved vaccine can continue to be used after the public health emergency of COVID-19 is declared to be over. It also makes it easier for certain entities, such as the military, to require vaccines.
Ostrosky hopes the approval will help the public “trust the process and trust the science and recognize that this vaccine has met the burden of proof of efficacy and safety.”
Is the vaccine booster shot the same as the first doses?
Yes. The booster shot is a third dose of whichever vaccine the person had received before. In rare instances, when the same vaccine is not available, the other mRNA vaccine can be safely administered instead, Kulkarni said.
Right now, a third dose is only recommended for certain immunocompromised people who had previously received either the Pfizer or Moderna vaccine. Houston-area hospitals began administering the boosters last week.
Starting the week of
Sept. 20, all Americans will be eligible for a booster if they are eight months post-second dose, according to the CDC. Those who were fully vaccinated first likely will be eligible in September for a booster.
A booster dose is not specifically recommended for people who received the Johnson & Johnson vaccine. That might change going forward.
What are monoclonal antibodies, and why are they important?
Monoclonal antibody therapy is a type of treatment that prevents the spread of COVID before it progress to a full infection. The antibodies, which are engineered in a lab, can be delivered either intravenously or by injection under the skin.
The therapy has been shown to have substantial benefits for people who have had a close, unprotected exposure to someone with active COVID-19 and are either not fully vaccinated or are immunocompromised, according to Kulkarni. It also benefits patients with mild to moderate COVID-19 who are at higher risk to progressing to severe COVID-19 because of their age or other underlying medical conditions.
Houston-area hospitals are administering the treatment, and more antibody infusion centers are opening across the state.
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