I have to take Tylenol on a daily, sometimes continual basis. I know from my own research and doc’s warning that taking more than 2 Tylenol at a time is rough on my liver, so I stick to the regular dose and make sure I wait the full number of hours before taking more. Unfortunately I also have a good handful of various prescribed medications I take every day, 15 or so, and I take all but 2 pills at once at night. I’m positive there are no negative interactions with the Tylenol, per my doc and my pharmacist.
My question is about my liver’s capacity to handle all these other pills if I’ve already maxed it out with the Tylenol. Without going into detail about the medications, why is this not harmful? Not one of my docs or pharmacist, or anything I’ve read has ever said anything about the impact on my liver from taking all this. But if 2 Tylenol is enough, surely people like myself having to take lots of other medications would do damage too? No?
It completely depends on what types of medications make up those 15 pills you take. Evidently they are medications that are not hard on the liver, as neither health care professional in your life raised any concerns. It’s not the number of pills or medications you take that determines whether or not your liver will be stressed, it’s the specific medication being taken.
Hopefully your doctor (and your pharmacist) is fully aware of all the pills you are taking, and is not just thinking “U is Ok with V; V is OK with W; W is OK with X; X is OK with Y; Y is OK with Z” without considering whether UVWXYZ are all OK together. If they both have a good handle on everything you are taking every day, I suppose it is probably alright.
Just because most drugs are processed, and detoxified, through the liver, I do not think that that necessarily means that they are toxic and dangerous to it, in the way that too much acetaminophen (Tylenol) is. I am not sure that even acetaminophen does any significant damage unless there is too much of it in your system at one. In most respects the liver is a pretty resilient organ, and you are probably just making it earn its keep. Lots of people, especially older people, take lots of different pills these days.
This actually is one of the areas where a good pharmacist will be of more help to you than your doctor.
The points made are very much on point. To rephrase:
Issue one is if there is any synergistic toxicity risk between any medications and if so does it reach a significant risk? As a doc I’d say the pharmacist is a better person to check on that than we are. But only a realtively few medications have significant risks for liver toxicity at typical dosing levels. If more than one medication you take is on that list then you may want to discuss it with your doctor and/or pharmacist.
Issue two is if any of the medications trigger adaptations in any of the liver or kidney systems that impact the clearance and metabolism of any of the other medications in either direction. That is not stressful on or harmful to the liver but does mean that doses might need to be adjusted based on the presence of other mediciations. Some of those adaptations only occur in certain people, further complicating this issue. A place to start on your own is this on-line medication interaction tracker. That said the pharmacy very likely utilizes a more sophisticated program to do much the same thing.
In effect, it is primarily your liver’s job to metabolize xenobiotic agents (fancy-pants way of saying drugs), so it’s got a very large capacity to do so. It is not the only organ to do so, btw, as the process starts in the GI tract and also occurs in the brain, kidneys, and lungs. To do this, it has a huge array of enzymes capable of phase I reactions (addition/exposure of a functional group like -OH, -COOH, -SH, etc, usually, but not always, reducing the pharmacologic efficacy of the drug in the process) and a different array of enzymes involved in phase II reactions (a molecule is stuck onto the previously exposed functional group, an example being glucuronidation, with the end product usually becoming more hydrophilic and easier to excrete via the kidneys). So long as the drugs involve different pathways, or don’t produce toxic middle-step products, and necessary cofactors (Glutathione, NADPH, etc) aren’t depleted and/or not replaced, the liver should not undergo any damage.
Tylenol undergoes metabolism via multiple different pathways. It’s major pathways end up involving glucuronidation and sulfation, but if those pathways end up saturated, an oxidative pathway contributes a bigger role, and it is this pathway that causes the toxicity problems. In effect, N-Acetyl-para-aminophenol (acetaminophen/paracetamol) gets converted to NAPQI (N-acetyl-parabenzoquinone imine) which is toxic. Your liver has a solution, however, and quickly sticks this molecule to Glutathione. High doses of APAP, however, can eventually eat up the liver stores of Glutathione and that’s when the damage starts.
You are largely correct. In general, I’m going to be more concerned about pharmacodynamic interactions with 15 different meds, as well as the possibility of irrational polypharmacy, than I am about hepatotoxicity (with exceptions for known hepatotoxic agents). The only slight nitpick would be that it’s either too much Tylenol OR diminished Glutathione reserves (or both) on a chronic basis.