Patients with drug-induced liver damage may still be able to take medications for chronic conditions safely, reports a new study. The findings of the study are published in the Drug Metabolism and Disposition. When you ingest a drug--whether over-the-counter Tylenol or medication prescribed by a doctor--your liver is your body's first responder, and just like other first responders, sometimes the liver gets hurt. Doctors used to make patients with drug-induced liver injury stop taking all their medications until the liver healed, but this could be dangerous.
Drug-induced liver injury, when a person accidentally harms their liver by taking medications prescribed by a doctor (or occasionally over the counter drugs), affects about 40,000 people in the US every year, and almost 1 million people globally.
"Doctors give patients drugs to treat diseases. No one wants their liver damaged, but it happens all the time," says UConn pharmacologist and toxicologist Xiaobo Zhong. When a person takes a medication by mouth, it goes into their stomach and then to the intestines, where it is absorbed into the blood. This blood, in turn, passes first through the liver before reaching the rest of the body. The liver has enzymes that break down medicines. But different people naturally have more or less of these enzymes. Sometimes, what could be a safe and effective dose in one person is too much for someone else who has different enzyme levels. This is why some individuals are more vulnerable to liver damage, even when taking drugs just as a doctor prescribed.
There is no standard guidance for doctors when a patient gets drug-induced liver damage. Often times, they tell the person to stop taking all medications immediately and wait for their liver to recover. But that can take weeks or months.
"But if patients have chronic conditions such as diabetes, hypertension, or depression, their conditions can run out of control," if they stop taking the medications, Zhong says. And that can be life-threatening.
Zhong, together with UConn toxicologist José Manautou, graduate student Yifan Bao, and colleagues at University of Michigan, University of Pittsburgh, and Zhengzhou University in Henan, China, tested whether mice whose livers had been damaged by acetaminophen (the active ingredient in Tylenol) had lower levels of drug-metabolizing enzymes, called cytochrome P450 enzymes.
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Levels of P450 enzymes vary a lot from person to person. The team recently published another paper looking at P450 enzymes, this one in Molecular Pharmacology with graduate student Liming Chen as lead author. That paper found that the way a cell regulates specific P450 enzymes made mice more or less susceptible to liver damage from acetaminophen.
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The team still has to test whether these results hold in humans. They are currently looking to collaborate with local emergency room doctors who see many patients with drug-induced liver damage to better understand how their studies in rodents translate to humans.
Source-Eurekalert