I am recovering from arthroscopic shoulder surgery, for repair of a Bankart lesion and fractures sustained during bilateral dislocations. Taking Hydro/APAP for pain. About 6 weeks out from surgery, 2 months out from initial injury. I use the Vicodin 3 times daily, that makes 1500mgs APAP, and an additional around 1000 from Tylenol. I know the daily allowance for adults is 4g, but from what I’ve read, this only applies for up to ten days. My docs don’t seem concerned, what’s the straight dope on longer-term APAP use and hepatotoxicity, esp. w/seizure control meds(cause of dislocations).?
Which seizure control meds? If said meds activate the liver’s cytochrome P-450 system, then the chronic use of acetaminophen (APAP) stands a greater risk of reducing your liver’s functional capacity to deal with metabolites and carry out normal body processes. It’s especially problematic for the barbiturates, phenytoin, and carbamazepine.
Also, chronic use of APAP in the range you mention has been correlated with acute tubular necrosis of the kidney, and a possible connection with kidney cancer.
Having said that, other sources do indicate that if the total daily dosage is kept under 3 grams, it is probably safe to use chronically. But perhaps not, if you’re on the above seizure meds. You’ll also want to avoid concomitant use of aspirin, and stay away from alcohol.
However, it might be wise to cut back where and when you can, and possibly explore other chronic pain therapeutic modalities, such as physical therapy, biofeedback, or even consider one of the newer pain agents such as gabapentin. You’d need to work with your doc on this, however.
http://agenet.agenet.com/link.asp?DOC_3122
Google “chronic acetaminophen use” for lots of good data
Seizure med is phenytoin, don’t drink and never use anything but acetaminaphen. I am in PT currently, after which is when I use Hydro/APAP… with APAP alone while at work. Also, if you have the time a short rundown of chronic tubular necrosis would be appreciated, does it have to do with immune complex formation with hepatic breakdown products(in the vein of glomerulonephritis)? Or is it of a different mechanism? Which should I be more concerned about, renal or hepatic toxicity with these meds at this dosage, I am tapering down and hope to be off(at least the APAP) soon. I’ve been informed the phenytoin is indicated for at least a year, possibly lifelong. Also, is there anything I can do to lessen the effects? Whats your take on milkthistle, I googled but I generally get a lot of snake-oil pitches and not much solid scientific evidence pro or con, except that it seems to be more widely used in Europe. I’m not a huge believer in herbal remedies.
Thanks,
Ben
With phenytoin, you are at greater risk for complications of chronic APAP use.
You might really want to ask your doc for a pain-killer which doesn’t contain APAP. Codiene, hydrocodone, and oxycodone are all available without the APAP in it. That would be one way to cut down on your APAP intake.
Acute tubular necrosis is a vast topic in itself. Tubular death is generally linked to the toxicity of an APAP molecule metabolite, IIRC. This link may be helpful. http://www.nephrologychannel.com/atn/
or this one, which is more technical: http://www.emedicine.com/MED/topic39.htm
Both your liver and kidneys are at risk. If you’re inclined to worry, worry about both.
Milkthistle is one of the few herbs which actually does have some benefit to the liver under certain circumstances, but I have no idea if it would help with preventing hepato-toxicity from APAP. Theoretically I suppose it could, as the active ingredient in milkthistle is thought to be silibinin, which hinders uptake of certain toxins by hepatocytes. Mucormyst, the treatment for liver damage due to APAP, has a similar mechanism.
Best advice is still to moderate your APAP use, especially in view of being on phenytoin. Mention your concerns to your doc. If he doesn’t listen, mention them again. Repeat until the concerns are addressed. Or get a new doc.
Greatly appreciated.