• If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.


No announcement yet.

Antibiotics Primer

This is a sticky topic.
  • Filter
  • Time
  • Show
Clear All
new posts

  • Antibiotics Primer

    Antibiotics Primer

    While I cannot offer specific advice regarding antibiotics for any particular member of this forum, I can speak in generalities about antibiotics. Nothing that follows should be construed as medical advice. Every patient, and every situation is different. And frankly, I am not qualified to give that sort of advice, even if I were tempted to do so.

    The assumption is, of course, that this information is for use when, and if, appropriate medical care is not available, as during a pandemic.

    The information provided here is not intended to be complete. It is a starting point, from which the reader should make inquiries of their personal physician, or begin their own research.

    Before we get into what antibiotics can do when appropriately applied, lets focus on what they cannot do.

    Antibiotics do not treat or cure viral infections.

    It sounds simple enough, but why then do doctors often prescribe antibiotics for patients’ with viral infections?

    Basically, for two reasons. Viral infections can lead to secondary bacterial infections, or can be difficult to differentiate from bacterial infections. Giving antibiotics can be viewed as a backup, in case the doctor’s initial impression of a viral infection is incorrect, and to prevent a secondary bacterial infection in patients seen to be at risk of developing one.

    Secondly, patients expect some sort of treatment for their $60 office visit, and frankly, antibiotics are what they expect. This practice has its downside however, and more and more cases of antibiotic resistant bacteria are reported each year.

    No one antibiotic will work with all infections.

    Although there are many fine `broad spectrum’ antibiotics available, each has its strengths and weaknesses, and some may be completely ineffective in some patients. Doctors, who often must guess at the type of infection without lab tests, must choose from a list of antibiotics that are generally known to be beneficial for common infections of different sites in the body.

    Doctors know, for instance, that zithromax (azithromycin) is generally very effective against upper respiratory infections, and so they prescribe it a lot. Urinary tract infections usually respond well to Cipro (Ciprofloxacin). Notice the words generally and usually. In some cases, these meds do not work, and a doctor will be forced to go to a second tier antibiotic, or await lab cultures to determine what (if any) antibiotic a bacteria may be susceptible to.

    Antibiotics can have serious and life threatening consequences.

    Though the incidence of fatal reactions to antibiotics is small, it does happen. Many people are allergic to various antibiotics, and can have sudden, and dramatic anaphylactic reactions. Those who are allergic to one class of antibiotics may find that they are also allergic to similar classes. A penicillin allergy may equate to an allergy to cephalosporins in 10% to 15% of the population.

    Often, allergic reactions are not life threatening, and only produce mild symptoms such as uticaria (rash), or itching. But full-blown anaphylaxis is a true medical emergency.

    Beyond allergies, the use of antibiotics can kill off the beneficial flora of the intestinal tract, and can allow dangerous blooms of bad (and sometimes fatal) bacteria. In recent years, the emergence of C. Difficile infections has grown markedly, and is now one of the biggest nosocomial (hospital acquired infections) doctors deal with.

    Blooms of candida albicans (a fungus) can also occur during long-term antibiotic administration. While rarely fatal, candida can promote diarrhea and dehydration.

    And of course, the use of the wrong antibiotic, or dealing with a resistant strain of bacteria, can put the patients’ life at risk.

    The bottom line is that antibiotics are powerful drugs, capable of doing great harm, and should not be taken lightly.

    Okay, if all antibiotics aren’t created equal, how do I choose one?

    First and foremost, talk to your doctor. Yes, I know, some doctors are not receptive to writing scripts for antibiotics `just in case’ you might need one during a pandemic. In some localities, particularly in places like the UK and Canada, there may be great restrictions as to what they can prescribe, and when.

    But your doctor should be your ally in your health care decisions, not your enemy. He or she will know best what you can safely take, and will hopefully be aware enough of the pandemic potential to write a script for you. But even with the assistance of your family physician, any antibiotic selected before the fact will be pure guesswork.

    Your other option, if you have a non-cooperating physician, is to research the various types of infections you expect to deal with, and select the most commonly used antibiotics for them. While antibiotics do require prescriptions, there are ways around that, and I will address those later in this essay.

    There are many considerations when choosing an antibiotic, and effectiveness is only one of them. Potential allergic reactions must also be considered. Some 10% to 15% of the population may have some sort of allergy to penicillin, for instance. Some antibiotics are not safe for small children, pregnant women, or nursing mothers. It is therefore wise to have the assistance of your doctor in making any selection of antibiotics for you and your family.


    It is always easier to avoid getting an infection than it is to treat it. With pandemic flu, the biggest infection concern is a secondary bacterial pneumonia. Getting an up to date pneumovax inoculation as a preventative is far better than relying on antibiotics later. It will not guarantee that you or a loved one will not suffer a secondary lung infection, but it will reduce the risks substantially.

    While you are at it, consider updating any other immunizations you may need, such as tetanus shots or whooping cough (pertussis). The American Academy of Pediatrics (AAP) recently recommended that kids who are 11-18 years old get a booster shot that includes a pertussis vaccine, preferably when they are 11 to 12 years old.

    The exercise of good hygiene, and proper wound care, can greatly reduce the need for antibiotics in a crisis. This cannot be overstated. During a prolonged crisis, we will likely find our diets poor, our stress levels high, and our immune systems less than effective.

    What are my Choices?

    There are literally hundreds of antibiotics available, some have very narrow uses, while others are considered `broad spectrum’. Luckily, we can narrow down the field a bit by taking cost, availability, and range of use into account.

    What follows is not necessarily comprehensive, but does cover the most common available antibiotics in the United States.

    Penicillins: (Amoxicillin, Ampicillin, Azlocillin, Carbenicillin, Cloxacillin, Dicloxacillin, Flucloxacillin, Mezlocillin, Nafcillin, Piperacillin, Ticarcillin)

    The great granddaddy of antibiotics, whose discovery is credited to Alexander Flemming in 1928, but which did not come into wide use until the early 1940’s. As penicillin is quickly excreted by the human body, and production of the antibiotic was difficult, during the war the use of probenecid (a gout medicine) was common to slow the metabolism of the drug. This is the same technique that many with limited supplies of Tamilfu plan to use to stretch their supplies.

    By the late 1940s, synthetic penicillin was created, and the first major development was ampicillin, which offered a broader spectrum of activity than either of the original penicillins and allowed doctors to treat a broader range of both Gram-positive and Gram-negative infections. Further developments led to amoxicillin, with improved duration-of-action.

    Amoxicillin today is widely used for the following conditions:

    Infections of the ear, nose, and throat – due to Streptococcus spp. (α- and β-hemolytic strains only), S. pneumoniae, Staphylococcus spp., or H. influenzae.

    Infections of the genitourinary tract – due to E. coli, P. mirabilis, or E. faecalis.

    Infections of the skin and skin structure – due to Streptococcus spp. (α- and β-hemolytic strains only), Staphylococcus spp., or E. coli.

    Infections of the lower respiratory tract – due to Streptococcus spp. (α- and β-hemolytic strains only), S. pneumoniae, Staphylococcus spp., or H. influenzae.

    Gonorrhea, acute uncomplicated (ano-genital and urethral infections) – due to N. gonorrhoeae (males and females).

    H. pylori eradication to reduce the risk of duodenal ulcer recurrence

    For dosing instructions a .pdf file on amoxicillin is available at:


    Tetracyclines: (Doxycycline, Vibramycin)

    While not as popular as it once was, due to a growing number of resistant forms of bacteria, Tetracyclines are often still prescribed for many infections.

    Tetracyclines may be used in the treatment of infections of the respiratory tract, sinuses, middle ear, urinary tract, intestines, and gonorrhoea.

    Doxycycline is viewed today as being superior to Tetracycline. From the Johns Hopkins website on community acquired pneumonias: Active against atypical strains including Legionella. It is dirt cheap, generally well tolerated, convenience of twice-daily dosing, and good activity in clinical trials despite its reputation as a "wimpish antimicrobial". The main disadvantage is variable rates of ********** by S. pneumoniae. This is a rational choice for an ambulatory patient without comorbidities.

    Doxycycline is also used as a prophylactic treatment for infection by Bacillus anthracis (anthrax) and is effective against Yersinia pestis, the infectious agent of bubonic plague. It is also used for malaria treatment and prophylaxis, as well as treating elephantiasis.

    They remain the treatment of choice for infections caused by chlamydia (trachoma, psittacosis, salpingitis, urethritis and L. venereum infection), Rickettsia (typhus, Rocky Mountain spotted fever), brucellosis, and spirochetal infections (borreliosis, syphilis, and Lyme disease). In addition, they may be used to treat anthrax, plague, tularemia, and Legionnaires’ disease.

    They may have a role in reducing the duration and severity of cholera, although drug-********** is occurring and their effects on overall mortality is questioned.

    While a reasonable choice for many infections, Tetracyclines should not be administered to children under the age of 8 (it may cause permanent staining of the teeth), and may induce photosensitivity in some patients, where sun exposure can result in severe sunburns. Tetracyclines may also adversely affect the effectiveness of oral contraceptives. Lastly, some patients experience GERD, or stomach upset, particularly from Doxycycline.

    Dosing information for Doxycycline can be found at :


    Azithromycin: (Zithromax)

    Azithromycin is closely related to erythromycin, but with the added advantage of having a longer half-life. It is excreted from the body slowly, and can therefore be taken for a shorter length of time. While expensive, it can actually cost less per course of treatment than less expensive antibiotics and today is one of the worlds most widely prescribed antibiotics.

    Azithromycin is used to treat certain bacterial infections, most often bacteria causing middle ear infections, tonsillitis, throat infections, laryngitis, bronchitis, pneumonia and sinusitis. It is also effective against certain sexually transmitted infectious diseases, such as non-gonococcal urethritis and cervicitis.

    Azithromycin is typically supplied in a 6 pill z-pack, where two pills are taken the first day, then 1 pill each day after that for 4 days. The drug can remain in the system for up to 10 days.

    Additional information can be found at :


    Ciprofloxacin (Cipro)

    Ciprofloxacin, a 4-quinolone, is one of the newer compounds of the fluoroquinolone class of antibiotics. Since its introduction in 1989, it has proven to be highly effective in the treatment of UTI’s (Urinary Tract Infections), and gained national fame after 9/11 due to its effectiveness in treating Anthrax. It is, however, also very effective in the treatment of nosocomial (Hospital acquired) pneumonias.

    Additional indications are infections such as acute sinusitis, lower respiratory infections, acute exacerbation of chronic bronchitis (AECB), complicated intra-abdominal infections, infectious diarrhea, infections of skin, bone and joints, as well as uncomplicated gonorrhea (cervical and urethral).

    It is FDA approved for the following conditions, although like many other drugs, it has off label applications

    Uncomplicated UTI (Cipro XR and Cipro); complicated UTI (Cipro).

    Endocervical and urethral infections caused N. gonorrhoeae (Note: high ********** rates reported in Hawaii and California).


    Pneumonia (nosocomial)

    Acute sinusitis

    Bone and joint infections

    Skin and soft tissue infections

    Empiric therapy for neutropenic fever (in combination with piperacillin)

    Post-exposure prophylaxis for inhalation anthrax.


    Usual dose: 500mg PO bid. UTI: 250mg PO bid or XR 500mg qd x 3d. Serious infections: 750mg PO bid or 400mg IV q8-12h. Nosocomial pneumonia 400mg IV q8h.


    Generally well tolerated. Occasional: GI intolerance, CNS-headache, malaise, insomnia, restlessness and dizziness. Rare: allergic reactions, diarrhea, photosensitivity, increased LFTs, tendon rupture, peripheral neuropathy, seizure.


    Any divalent and trivalent cations (i.e sucralfate, antacid, vitamins, and minerals): do not co-administer or give cipro 2hrs prior. Theophylline, mexiletine, and warfarin (R) effects may increase with ciprofloxacin co-administration.

    Further Information on Cirpo may be found at the following site:


    Metronidazole (Flagyl)

    Flagyl is not a broad spectrum antibiotic, and so its usage is limited. But when you need it, your really need it. Because some of its applications are a bit obscure, I've added some background information on Giardia, Dysentery, and C. Diff infections.

    PRESCRIBED FOR: Metronidazole is used to treat giardia infections of the small intestines, amebic liver abscess and dysentery (amebic colon infection causing bloody diarrhea), trichomonas vaginal infections, and carriers of trichomonas (both sexual partners) who do not have symptoms of infection. Metronidazole is also used in treating colon infection caused by a bacteria called C. difficile.

    DOSING: Metronidazole may be taken with or without food.. Metronidazole is metabolized mainly by the liver and dosages may need to be reduced in patients with abnormal liver function.

    DRUG INTERACTIONS: Alcohol should be avoided because metronidazole and alcohol together can cause severe nausea, vomiting, cramps, flushing, and headache. Metronidazole can increase the blood thinning effects of warfarin (Coumadin) and increase the risk of bleeding. Cimetidine (Tagamet) increases the blood level of metronidazole.

    Recommended dosage ADULT


    A (generally) water-borne pathogen, an intestinal protozoa (cyst) that is often found in lakes and streams.


    a.. A small number of persons develop abrupt onset of explosive, watery diarrhea, abdominal cramps, foul flatus, vomiting, fever, and malaise; these symptoms last 3-4 days before transition into the more common subacute syndrome.
    b.. The majority of patients experience a more insidious onset of symptoms, which are recurrent or resistant.
    c.. Stools become malodorous, mushy, and greasy. Watery diarrhea may alternate with soft stools or even constipation. Stools do not contain blood or pus because dysenteric symptoms are not a feature of giardiasis.
    d.. Upper GI symptoms, often exacerbated by eating, accompany stool changes or may be present in the absence of soft stools. These include upper and midabdominal cramping, nausea, early satiety, bloating, sulfurous belching, substernal burning, and acid indigestion.

    Treatment : ORS, Flagyl (Metronidazole) 250 mg po tid for 5-7 d.

    Acute Intestinal Amebiasis (Acute Amebic Dysentery)

    Background: Amebiasis is a parasitic infection caused by the protozoon Entamoeba histolytica. It is the third leading parasitic cause of death worldwide, surpassed only by malaria and schistosomiasis. On a global basis, amebiasis affects approximately 50 million persons each year, resulting in nearly 100,000 deaths.

    a.. Acute amebic colitis has a gradual onset presenting with a 1- to 2-week history of abdominal pain, diarrhea, and tenesmus (constant feeling of the need to empty the bowel). Stool samples, which are watery and contain blood and mucus, have little fecal material. Fever is noted in only a minority of patients. Lower quadrant abdominal tenderness may be noted.
    b.. Fulminant amebic colitis is a rare complication of amebic dysentery. It presents with a rapid onset of severe bloody diarrhea, severe abdominal pain, and high fever. Children younger than 2 years are at increased risk. Intestinal perforation is common.
    c.. Chronic amebic colitis is clinically similar to inflammatory bowel disease. Recurrent episodes of bloody diarrhea and vague abdominal discomfort develop in 90% of patients with chronic amebic colitis who have antibodies to E histolytica.

    While not a common problem today in western civilization, Dysentery could make a comeback if a pandemic occurs and our sanitation standards are compromised.

    The usual dose is 750 milligrams taken by mouth 3 times daily for 5 to 10 days. ORS

    Suspected C. Difficile Infection

    Background: Clostridium difficile is a gram-positive, anaerobic, spore-forming bacillus that is responsible for the development of antibiotic-associated diarrhea and colitis. C difficile was first described in 1935 as a component of the fecal flora of healthy newborns and was initially not thought to be a pathogen. It was named difficile because it grows slowly and is difficult to culture. While early investigators noted that the bacterium produced a potent toxin, the role of C difficile in antibiotic-associated diarrhea and pseudomembranous colitis was not elucidated until the 1970s.

    C difficile infection commonly manifests as mild-to-moderate diarrhea, occasionally with abdominal cramping. Approximately 20% of individuals who are hospitalized acquire C difficile during hospitalization, and more than 30% of these patients develop diarrhea. Thus, C difficile colitis is currently one of the most common nosocomial infections.

    The diagnosis of C difficile colitis should be suspected in any patient with diarrhea who has received antibiotics within the previous 2 months and/or when diarrhea occurs 72 hours or more after hospitalization.

    TREATMENT: Flagyl 500 mg PO tid or 250 mg PO qid for 10-14 d. ORS for dehydration.

    Additional Information on Metronidazole/Flagyl may be found at:


    How do I obtain antibiotics?

    Once again, ask your doctor. He or she is best able to help you decide what you should, or should not have in your medicine chest. But if that doesn’t work, and you are determined to obtain antibiotics elsewhere, you have a couple of options.

    First, there are offshore pharmacies in places like Mexico, and Thailand that will sell antibiotics without prescriptions. There are also prescription brokerage companies that have a doctor who will write prescriptions for their clients. This is a semi-dangerous tactic, as the product you receive may not be quite as advertised, and you run the risk of running afoul of US customs and having your package seized, or worse. If you live near the US/Mexican border, you can generally cross over, go into any farmacia , and purchase common antibiotics over the counter. Customs agents will now, reportedly, turn a blind eye to the importation of a 90-day supply of non-scheduled (narcotic) drugs.

    Your other option, and this is admittedly a desperation move, is to purchase antibiotics not intended for human consumption. While I cannot recommend this course of action, one need only google `fish antibiotics’ to find suppliers of amoxicillin, tetracycline, and Cephalexin intended for aquarium use. While reportedly produced in the same manufacturing plants as antibiotics for human consumption, quality assurance is probably not as good, and so there is some risk of receiving older, less potent antibiotics.

    How do I know when to give antibiotics?

    Without lab tests, you are basically flying blind when it comes to administering antibiotics. You can only guess, and hope you guessed right.

    A few simple signs of bacterial lung infection are upper or lower respiratory infections which are accompanied by fever and a productive cough with yellow or green sputum. Of course, you will have no idea what the source of the infection is, or what antibiotic it will be susceptible to, but at least you will have an idea that an infection is present.

    Generally speaking, secondary pneumonia develops 4 to 6 days after the onset of a viral infection. During a viral infection, inflammation of the lungs can produce an abundance of proteins, call cytokines, and flood the lungs with fluids. These fluids are a prime breeding ground for bacterial infections.

    A patient who appears to be recovering, and whose condition degrades after the 4th day, may well have developed a secondary pneumonia. Antibiotics could therefore be given once a patients condition deteriorated, or if in ample supply, starting on the 2nd day of viral infection as a prophylaxis. Once again, speaking to your doctor in advance is your best option.

    An Antibiotic Strategy

    Regardless of how you obtain your antibiotics, once you have them selected, then research that antibiotic, and the infections it will treat on the Internet. Printout all the information you can find, including signs and symptoms of specific infections.

    In all likelihood, you will have only one or possibly two antibiotics in your arsenal, so the amount of information you will need to gather is limited. You can probably safely ignore obscure diseases, and concentrate on those you are likely to encounter. Having a copy of the PDR (Physicians Desk Reference) is highly recommended, as is the Merck Manual.

    There are a number of excellent web resources, including the Johns Hopkins website at http://www.hopkins-abxguide.org/main.cfm where you can look up information on antibiotics by the antibiotic, the pathogen, or the site of infection. Highly recommended.

    Self-diagnosis and self-medicating with prescriptions is a terrible idea, fraught with danger, and with a limited upside. But, during a prolonged crisis with no availability of medical care, it beats the alternative. Arm yourself with the best information you can acquire, enlist the aid of your personal physician if possible, and pray you never have to resort to blindly taking (or dispensing) antibiotics without proper medical guidance.

  • #2
    Well done

    Great post, most informative !


    • #3
      Thanks Inf,NCO
      “The key is to hit them hard, hit them fast, and hit them repeatedly. The one shot stop is a unit of measurement not a tactical philosophy.” Evan Marshall


      • #4
        I get a crowd pleasing case of either Bronchitis or a sinus infection almost every year. I then sell the mucus and other gack I cough up to the company DAP for use in filling nail and screw holes in sheet rock!

        Seriously, it's Satanic. Gwab it into the sink and even 140 degree hot water won't wash it down, it just flutters like some underwater tropical plant! (gotta use your finger...LOL)

        As far as Zithromax goes, in my opinion it's crap, I might as well eat a bag of Skittles, because it does me about as much good.

        Penicillin will give you the Blasters, the kind where the bathroom ends up having a brown ring around it, except for 2 bald spots, where your knees where!

        I hate Penisillin, but it's good for catching up on your reading in the throne room, just be careful your legs don't go to sleep due to setting your elbows on them, while reading the Wall Street Journal for a 2 hours straight. You feel really stupid not being able to get off the John, because you can't feel your damn legs anymore.

        Avelox is the Daddy-Mac, it's excellent, kicks the crap out of any infection I ever got and without the normally expected side effects of diarrhea, headaches, dry mouth accompanied by a mediciny taste, etc. Trust me, ask your doctor for Avelox! (it will also make you as horny as a Bangkok Prostitute, not that I would notice (nudge-nudge), but you will.

        My Lady doctor is pretty cool (and wants to do me), so she always allows me refills, therefore, I have some to fall back on, plus I know where she lives, meeow.

        Here's some additional info on Avelox:

        KMA - KGC - THA - #01

        '308 Holes Make Invisible Souls'

        'The Path of Excess Leads to the Palace of Wisdom'

        'Crush Your Enemies, See Them Driven Before You, Hear the Lamentations of their Women'

        You cannot invade mainland America.
        There would be a rifle behind every blade of grass.

        Isoroku Yamamoto, Japanese Admiral


        • #5
          My Lady doctor is pretty cool (and wants to do me), so she always allows me refills, therefore, I have some to fall back on, plus I know where she lives, meeow.

          Guess that's what powerlifting does for you, eh?


          • #6
            Very Informative post ,#1.Ive been trying to narrow the antibiotic shopping list to managable level.This will be a tremendous help but ratholing a supply will be tough thru the VA.Attempting to convince a VA doc to prescribe even antibiotics for a possible shtf event may find you in the
            rubber lock down ward!That leaves vet supply and very accurate scale, or more expensive Dr visits which may or may not yield the desired results w/o
            DR.Shopping,pretty expensive prop.


            • #7
              Originally posted by Fragmatic View Post

              Guess that's what powerlifting does for you, eh?

              Yep, there's a couple of reasons they call me Big Daddy.
              KMA - KGC - THA - #01

              '308 Holes Make Invisible Souls'

              'The Path of Excess Leads to the Palace of Wisdom'

              'Crush Your Enemies, See Them Driven Before You, Hear the Lamentations of their Women'

              You cannot invade mainland America.
              There would be a rifle behind every blade of grass.

              Isoroku Yamamoto, Japanese Admiral


              • #8
                I could mention old nicknames such as elephant man among the fairer sex but as this is a family oriented site...I hope it wasnt looks they were referring to!?


                • #9
                  Sorry to hear about the EARS...hehehe
                  KMA - KGC - THA - #01

                  '308 Holes Make Invisible Souls'

                  'The Path of Excess Leads to the Palace of Wisdom'

                  'Crush Your Enemies, See Them Driven Before You, Hear the Lamentations of their Women'

                  You cannot invade mainland America.
                  There would be a rifle behind every blade of grass.

                  Isoroku Yamamoto, Japanese Admiral


                  • #10
                    How appropriate,The "Antibiotics Primer".


                    • #11
                      Hey "Big Daddy", is there any woman who doesn't want to do you?



                      • #12
                        Originally posted by otobesane1 View Post
                        Hey "Big Daddy", is there any woman who doesn't want to do you?

                        Ohhh, there's a wife/mother joke there...


                        • #13
                          Judging from my Prostatitis, while it was the Cipro that "cured" it the Levaquin had the least amount of side affects.

                          Cipro caused (for ME): depression, anxiety, erectile dysfunction (though the urologist says this is probably more likely related to the Prosta**** itself and not the antibiotic), headaches/dizzyness, and severe irritation down under - the skin became so blistered and inflamed I had to go on Levaquin and I still get occasional flair ups.


                          • #14
                            Approx % coverage?

                            Would the 4 classes of antibiotics mentioned pretty much cover the most common or majority of possible bacterial infections?In addition any reccomendations for aid (books/manuals)in diagnosing the particular infection and appropriate

                            Maybe beyond the scope of the post but any real reasons to consider intramuscular antibiotic injectables over oral administration.Of course speed
                            of the initial dose i understand could be very important but risk worth the reward.Many injectable antibiotics mentioned are for now available via vetrinary clinics sterile water or saline solution shouldnt be difficult to make /aquire plus a very accurate scale to measure dose and as far as m aware any size of syringe are available w/o scripts

                            Again, very informative post,possibly lifesaving.