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There are plenty of drugs with a narrow therapeutic index (NTIs or NTIDs), some of which are available over the counter. Some extremely popular ones: lithium, v

There are plenty of drugs with a narrow therapeutic index (NTIs or NTIDs), some of which are available over the counter. Some extremely popular ones: lithium, valproic acid, acetaminophen, almost all anticoagulants (warfarin/heparin), almost all of the -mycin antibiotics (and a lot of other antibiotics), all of the tricylic antidepressants. See this paper for a very interesting discussion of the topic: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4412688/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4412688/

et2o 7y ago
People taking warfarin literally have serum levels measured frequently. Typically lithium and valproate too. TCAs barely used any longer. Acetaminophen doesn’t belong in this conversation with the other drugs.
- Johnny555 7y ago
  Acetaminophen doesn’t belong in this conversation with the other drugs. I don't see why not? It's a good example where the max therapeutic dose (4000mg/day) is within 2X of the toxic dose range (7500mg-10000mg/day). And even the max therapeutic dose can be toxic to the liver. And it's exceptionally easy to accidentally overdose if you don't read product labels, since you could be taking multiple products that contain it.
  - et2o 7y ago
    Almost no one should be taking 4g of acetaminophen a day. That’s definitely going to be toxic given enough time. It doesn’t belong in convo with other drugs because it requires far less monitoring. It’s also not taken chronically like the other drugs. Or shouldn’t be, at least.
    - Johnny555 7y ago
      Maybe they shouldn't, but isn't that kind of the whole problem with overdose? People take a higher dose than they should? Acetaminophen overdose is the leading cause for calls to Poison Control Centers (>100,000/year) and accounts for more than 56,000 emergency room visits, 2,600 hospitalizations, and an estimated 458 deaths due to acute liver failure each year.Data from the U.S. Acute Liver Failure Study Group registry of more than 700 patients with acute liver failure across the United States implicates acetaminophen poisoning in nearly 50% of all acute liver failure in this country. Available in many single or combination products, acetaminophen produces more than 1 billion US dollars in annual sales for Tylenol products alone. It is heavily marketed for its safety compared to nonsteroidal analgesics. By enabling self-diagnosis and treatment of minor aches and pains, its benefits are said by the Food and Drug Administration to outweigh its risks. It still must be asked: Is this amount of injury and death really acceptable for an over-the-counter pain reliever? https://www.ncbi.nlm.nih.gov/pubmed/15239078 https://www.ncbi.nlm.nih.gov/pubmed/15239078
      - et2o 7y ago
        I have lost track of the point of this conversation. If you think acetaminophen is qualitatively the same as warfarin or lithium, you need to go to med school.
    - refurb 7y ago
      4g of acetaminophen is what you'd take if you followed the directions of an adult taking 2 regular strength tablets every 4 hours for 24 hours (3.9g to be exact).
      - et2o 7y ago
        I understand that. That said, any physician who sees a patient taking 4g of acetaminophen a day chronically is going to tell them to reduce their dosage, switch to another drug, or stop. It’s not safe in the long run.
refurb 7y ago
Lithium, valproic acid, anticoagulants and -mycin antibiotics (topical excluded) and all anti-depressants are not available OTC in the US. Acetaminophen has a therapeutic index of close to 8, much better than chloroquine.
- eindiran 7y ago
  I am not really sure why you think I was listing only OTC drugs. Chloroquine does require a prescription in the US, so comparison with other prescription drugs seems entirely reasonable to me. Two points on the topic of OTC drugs in the US: 1. Unfortunately you can buy Lithium as a supplement in the US. I have seen bottles of it for sale on Amazon. 2. Having seen enough accidental (not to mention intentional) overdoses from Acetaminophen, I wouldn't be so fast to act like the therapeutic index is wide enough to be treated as "safe". Anything with a narrow therapeutic window needs to be weighed carefully before use. I hope your take away from my comment wasn't that I think chloroquine is "safe": merely that there are a lot of drugs with narrow windows, and there are trade-offs associated with their use. I included that paper because it discusses this very explicitly.
  - refurb 7y ago
    I missed the "some of which are OTC". My mistake. You are correct that there is a "gray market" for some compounds. The FDA won't come after you for selling lithium carbonate as long as you're not touting it as a medicine. I assume that if it became widespread enough and people got injured, those products would be pulled off the market pretty quickly. My comments of the TI for acetaminophen was more that it was larger than that for chloroquine. No drug is "safe", but some are safer than others.

et2o 7y ago

People taking warfarin literally have serum levels measured frequently. Typically lithium and valproate too. TCAs barely used any longer. Acetaminophen doesn’t belong in this conversation with the other drugs.

Johnny555 7y ago
Acetaminophen doesn’t belong in this conversation with the other drugs. I don't see why not? It's a good example where the max therapeutic dose (4000mg/day) is within 2X of the toxic dose range (7500mg-10000mg/day). And even the max therapeutic dose can be toxic to the liver. And it's exceptionally easy to accidentally overdose if you don't read product labels, since you could be taking multiple products that contain it.
- et2o 7y ago
  Almost no one should be taking 4g of acetaminophen a day. That’s definitely going to be toxic given enough time. It doesn’t belong in convo with other drugs because it requires far less monitoring. It’s also not taken chronically like the other drugs. Or shouldn’t be, at least.
  - Johnny555 7y ago
    Maybe they shouldn't, but isn't that kind of the whole problem with overdose? People take a higher dose than they should? Acetaminophen overdose is the leading cause for calls to Poison Control Centers (>100,000/year) and accounts for more than 56,000 emergency room visits, 2,600 hospitalizations, and an estimated 458 deaths due to acute liver failure each year.Data from the U.S. Acute Liver Failure Study Group registry of more than 700 patients with acute liver failure across the United States implicates acetaminophen poisoning in nearly 50% of all acute liver failure in this country. Available in many single or combination products, acetaminophen produces more than 1 billion US dollars in annual sales for Tylenol products alone. It is heavily marketed for its safety compared to nonsteroidal analgesics. By enabling self-diagnosis and treatment of minor aches and pains, its benefits are said by the Food and Drug Administration to outweigh its risks. It still must be asked: Is this amount of injury and death really acceptable for an over-the-counter pain reliever? https://www.ncbi.nlm.nih.gov/pubmed/15239078 https://www.ncbi.nlm.nih.gov/pubmed/15239078
    - et2o 7y ago
      I have lost track of the point of this conversation. If you think acetaminophen is qualitatively the same as warfarin or lithium, you need to go to med school.
  - refurb 7y ago
    4g of acetaminophen is what you'd take if you followed the directions of an adult taking 2 regular strength tablets every 4 hours for 24 hours (3.9g to be exact).
    - et2o 7y ago
      I understand that. That said, any physician who sees a patient taking 4g of acetaminophen a day chronically is going to tell them to reduce their dosage, switch to another drug, or stop. It’s not safe in the long run.

refurb 7y ago

Lithium, valproic acid, anticoagulants and -mycin antibiotics (topical excluded) and all anti-depressants are not available OTC in the US. Acetaminophen has a therapeutic index of close to 8, much better than chloroquine.

eindiran 7y ago
I am not really sure why you think I was listing only OTC drugs. Chloroquine does require a prescription in the US, so comparison with other prescription drugs seems entirely reasonable to me. Two points on the topic of OTC drugs in the US: 1. Unfortunately you can buy Lithium as a supplement in the US. I have seen bottles of it for sale on Amazon. 2. Having seen enough accidental (not to mention intentional) overdoses from Acetaminophen, I wouldn't be so fast to act like the therapeutic index is wide enough to be treated as "safe". Anything with a narrow therapeutic window needs to be weighed carefully before use. I hope your take away from my comment wasn't that I think chloroquine is "safe": merely that there are a lot of drugs with narrow windows, and there are trade-offs associated with their use. I included that paper because it discusses this very explicitly.
- refurb 7y ago
  I missed the "some of which are OTC". My mistake. You are correct that there is a "gray market" for some compounds. The FDA won't come after you for selling lithium carbonate as long as you're not touting it as a medicine. I assume that if it became widespread enough and people got injured, those products would be pulled off the market pretty quickly. My comments of the TI for acetaminophen was more that it was larger than that for chloroquine. No drug is "safe", but some are safer than others.