Monday, 28 December 2015

07:56 – One of the most frequent prepping-related queries I get has to do with antibiotics: Are animal antibiotics safe for human use? Are antibiotics safe to use after their “expiration dates”? Which specific antibiotics should I store, and how should I store them? And so on.

First, I’ll emphasize that I’m not a physician or pharmacist. What follows is just my own opinion, so take it for what it’s worth. But fish and bird antibiotics sold by companies like Thomas Labs are apparently identical to the same antibiotics labeled for human use, right down to the capsule colors and identification numbering. They almost certainly come from the same manufacturing plants in the same batches. So, yes, in my (very) qualified lay opinion fish/bird antibiotics that are also sold for human use are safe to use in humans. I’ve done titers/assays of several of several of these drugs in human versus bird/fish forms and found that activity levels are within allowable limits. There’s probably more variation from one batch to the next than there is in human versus animal forms.

As to expiration dates, the federal government has required them since the late 70’s, but like food best-by dates they’re pretty meaningless. Numerous rigorous studies have determined that these drugs remain safe and effective for years or decades past their “expiration dates”, and that’s when they’re stored at room temperature. Frozen, their useful lives are essentially unlimited. All those dates really mean is that the manufacturer doesn’t guarantee anything if the drug is used after the date on the label.

Back in the early 60’s, there were some problems with toxicity in outdated tetracycline, but that appears to have been a manufacturing issue that was soon resolved. As best I can determine from an exhaustive literature search, tetracyclines produced in the last 50 years or so have not exhibited toxicity when used after their expiration dates. In an emergency, I wouldn’t hesitate for even a millisecond about using 20-, 30-, or 40-year old antibiotics, particularly if they’d been stored frozen. In a long-term emergency, having any antibiotics available may well mean the difference between life and death.

As to which antibiotics to store, it’s a question of depth versus breadth. I’d love to have a thousand courses of a dozen different antibiotics available, but that’s simply not practical in terms of cost, storage space, and so on. For most people, the best option will be to have a lot of a few antibiotics and a little of several others.

The trick is to decide which classes of antibiotics to store in quantity, and which member of each class. For example, unless you or someone in your family has a penicillin allergy–and maybe even if someone does–you’ll probably want to store larger amounts of β-lactam antibiotics (penicillins, cephalosporins, and carbapenems). Within that class, there are dozens of specific antibiotics, including penicillin itself, amoxicillin, ampicillin, various generations of cephalosporins (Keflex, etc.) and so on. Broadly speaking, most antibiotics in a class have similar spectra, and differ mainly in things like dosage frequency and amount, and so on. One member of the class may be the preferred option. For example, doxycline is the first choice for treating Lyme Disease, but other tetracyclines are also active against that bacteria. In other words, if you find yourself without doxycycline but have tetracycline or oxytetracycline, you can generally substitute one of them successfully.

Drug resistance is also an issue, and one way of dealing with it is to use combinations of drugs. For example, resistance to amoxicillin is so widespread that many physicians now treat it almost as a placebo. But many bacteria that are resistant to plain amoxicillin can be treated successfully with a combination of amoxicillin and potassium clavulanate (AmoxiClav). Similarly, many bacteria that are resistant to plain sulfa drugs can be treated with a combination such as SMZ/TMP (sulfamethoxazole/trimethoprim). Unfortunately, with the exception of SMZ/TMP, most combinations are not sold for bird/fish use. Still, these are the versions that you really want.

Still another issue is the chemical form of the drug. Antibiotics sold for veterinary use are not necessarily usable for humans because of differences between species. For example, penicillin G potassium in oral form is widely used by vets to treat infections in cattle, sheep, goats, horses, and so on. It works great in ruminants and horses because their digestive systems work on cellulose and other plant matter. In humans and other carnivores/omnivores, penicillin G potassium can’t be used orally because our stomach acids destroy the drug before it can be absorbed. (Regardless, I keep a large amount of this antibiotic on hand, because it can be used successfully in humans if administered by injection, retention enema, or suppositories.) For some forms of some other antibiotics, the issues are similar. For example, erythromycin for use in livestock is usually supplied as the phosphate salt, which is also destroyed by human stomach acid. Erythromycin intended for oral use in humans is supplied either in enteric-coated form or as the stearate salt, which is resistant to stomach acid. But again, the phosphate salt can be used successfully in humans via injection or by retention enema or suppositories.

So, which antibiotics should you stock in larger quantities? I’d recommend at least a couple of full courses of each of the following, more if you’re prepping for more than just a couple of people:

  • Amoxicillin/clavulanate – Buy 875/125 mg capsules. In adults, a typical course of treatment would be one capsule every 12 hours for 10 days, so you’d need 20 per course. Because Amoxiclav is much more expensive than plain amoxicillin, you might want to modify the course to five days of Amoxiclav at 1,000 mg twice a day followed by five more days of plain amoxicillin at 1,000 mg twice a day.
  • Sulfamethoxazle/Trimethoprim (SMZ/TMP) – Buy 400/80 mg or 800/160 mg tablets, which can be split. In adults, the usual course is one 400/80 mg tablet twice a day for ten days.
  • Metronidazole – Buy 400 mg tablets. Metronidazole is effective against many bacteria, particularly anaerobes, as well as many protozoa like giardia. Adult dosage amounts and frequencies vary with the disease being treated, but a typical dosage is a total of 2,000 to 4,000 mg per day, divided into three or four doses, for five to ten days.
  • Ciprofloxacin – Buy 500 mg tablets. Typical adult dose is 500 mg twice a day for seven to fourteen days, although some serious diseases like anthrax require that dosage for 60 days or more.
    Which should be enough to get you started.