- FDA advises not to take Pfizer’s antiviral pills with other drugs.
- The FDA has released a complete list of drugs that may interact negatively with ritonavir in its Paxlovid information page, including those that should not be used with Covid antivirals.
- Many medication interactions, however, are tolerable, according to pharmacists, and should not prevent most individuals from using Paxlovid.
Pfizer’s pills may react negatively with other drugs
The first antiviral medications for Covid-19 promise vitally needed protection for patients at risk of severe sickness as the omicron surge wreaks havoc on a pandemic-weary society. However, many people who are prescribed Pfizer or Merck’s new drugs will need to be closely monitored by doctors and pharmacists, and experts warn that the antivirals may not be safe for everyone.
The Food and Drug Administration approved Pfizer’s Paxlovid for mild to moderate Covid in children as young as 12 who have underlying illnesses including heart disease or diabetes that increase the risk of hospitalization and mortality from the coronavirus. However, one of the antiviral cocktail’s two agents might have serious or life-threatening interactions with common pharmaceuticals including statins, blood thinners, and antidepressants. Paxlovid is also not recommended by the FDA for patients who have severe renal or liver problems.
Because of concerns regarding molnupiravir’s possible adverse effects, the FDA has limited its use to adults and only in situations when other approved therapies, such as monoclonal antibodies, are unavailable or not “clinically suitable.”
Two pills of the antiviral nirmatrelvir and one tablet of ritonavir, a medication that has long been utilized as a boosting agent in HIV regimens, make up the Paxlovid cocktail. Ritonavir inhibits CYP3A, a crucial liver enzyme involved in the metabolism of numerous drugs, including nirmatrelvir. Ritonavir reduces the body’s degradation of the active antiviral and helps it stay at a therapeutic level for longer in Paxlovid therapy.
Paxlovid’s remarkable success in clinical trials was almost certainly due to the boosting effect.
When Paxlovid is used with other medications that are also processed by the CYP3A enzyme, the main concern is that the ritonavir component will increase the hazardous levels of the co-administered pharmaceuticals.
Complicating things, the medicines that represent a risk of interaction are commonly provided to those who are at the highest risk of Covid due to other medical issues.
Blood thinners, anti-seizure medications, drugs for irregular heart rhythms, high blood pressure, and high cholesterol, antidepressants and anti-anxiety medications, immunosuppressants, steroids (including inhalers), HIV treatments, and erectile dysfunction medications are just a few examples of the medications.
Several medications tolerable say Pharmacists
The FDA has released a complete list of drugs that may interact negatively with ritonavir in its Paxlovid information page, including those that should not be used with Covid antivirals.
Many medication interactions, however, are tolerable, according to pharmacists, and should not prevent most individuals from using Paxlovid.
“Pharmacists are highly trained specialists in drug safety and monitoring, and they’re a fantastic source of knowledge and guidance on interactions between medicines, supplements, and herbal items,” said Emily Zadvorny, executive director of the Colorado Pharmacists Society. “They will assist in determining whether a major interaction occurs andif so, devising strategies to lessen the interaction.”