Anthrax Treatment

What if I develop side effects from the antibiotic?

If you develop side effects from the antibiotic, call your healthcare provider immediately. Depending on the type of side effects, you may be able to continue taking the medicine, or may be switched to an alternative antibiotic. If necessary, your physician may contact your State Department of Health for consultation on possible alternate antibiotics.

Has CDC tested the anthrax isolates for sensitivity to different antibiotics?
Yes. Antibiotic sensitivity testing performed at CDC has determined that the strain of anthrax was sensitive to a wide range of antibiotics, including penicillin and ciprofloxacin, giving public health officials important treatment information.

What are the risks of using tetracyclines and fluoroquinolones in children; are alternatives available?
Risks of using tetracyclines and fluoroquinolones in children must be weighed carefully against the risk for developing a life-threatening disease due to B. anthracis. Both agents can have adverse health reactions in children. If adverse reactions are suspected, therapy may be changed to amoxicillin or penicillin.

Are there special instructions for taking ciprofloxacin or doxycycline?
As with all antibiotics, take the medication according to the schedule you were instructed, and even if you begin to feel better, continue taking it for the full number of days. If you need an extension of the antibiotic at the end of your prescribed number of days, local emergency healthcare workers or your healthcare provider will inform and tell you how to get more medicine. They may also tell you to discontinue the antibiotic, or will change the type of antibiotic, depending on results of laboratory tests.

After I have started taking ciprofloxacin to protect me from developing anthrax, what side effects could I get from taking this antibiotic?
Side effects which sometimes occur include nausea, mild diarrhea, stomach pain, headache and dizziness. Talk with your doctor if you have any of these problems while you are taking the antibiotic. Certain foods and medications should not be taken with ciprofloxacin; this should be discussed at the time the antibiotic is prescribed, so that side effects will not occur from the combinations. Ciprofloxacin also can cause sun sensitivity which increases the chances of sunburn. More serious side effects include central nervous system side effects such as confusion, tremors, hallucinations, depression, and increased risk of seizures. High blood pressure and blurred vision are also possible. Allergic reactions could cause difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; hives or severe diarrhea. Pain, inflammation, or rupture of a tendon are possible and also severe tissue inflammation of the colon could occur. Call your doctor or seek medical advice right away if you are having any of these side effects.

This list is NOT a complete list of side effects reported with ciprofloxacin. Your healthcare provider can discuss with you a more complete list of side effects.

After I have started taking doxycycline to protect me from developing anthrax, what side effects could I get from taking this antibiotic?
Less serious side effects include diarrhea, upset stomach, nausea, sore mouth or throat, sensitivity to sunlight, vaginal yeast infection or itching of the mouth lasting more than 2 days. You should talk with your doctor if you have any of these problems while taking doxycycline. Certain foods and medications should not be taken with doxycycline, and this should be discussed with your healthcare provider at the time the antibiotic is prescribed, so that side effects will not occur from the combinations. Doxycycline also causes sun sensitivity which increases the chances of sunburn. Serious side effects of doxycycline that are possible but uncommon include: life-threatening allergic reaction (symptoms are trouble breathing; closing of the throat; swelling of the lips, tongue, or face; hives), blood problems (symptoms are unusual bleeding or bruising), liver damage (symptoms are yellowing of the skin or eyes, dark urine, nausea ,vomiting, loss of appetite, abdominal pain), irritation of the esophagus. Call your doctor or seek medical attention right away if you are having any of these side effects. This list is NOT a complete list of side effects reported with doxycycline. Your healthcare provider can discuss with you a more complete list of side effects.

Why is CDC recommending doxycycline instead of ciprofloxacin for the treatment and prevention of anthrax?
Both doxycycline and ciprofloxacin are effective in treating Bacillus anthracis that we are dealing with in these investigations. Although CDC first recommended the use of either drug for postexposure prophylaxis for the prevention of inhalational anthrax, we are now recommending doxycycline in order to prevent other bacteria from developing resistance to ciprofloxacin. Ciprofloxacin is part of the fluoroquinolone family of drugs, a relatively new class of antibiotics used to treat infections caused by organisms for which doctors do not have information about antimicrobial susceptibility. This kind of treatment is known as empiric therapy. Ciprofloxacin and other fluoroquinolones are used for empiric treatment for a variety of serious and common infections in the United States, including pneumonia, gastrointestinal infections, and urinary tract infections. The number of people who have been exposed to B. anthracis and need antibiotics has increased dramatically since CDC first issued guidelines for treatment. If all those people take ciprofloxacin, other bacteria they carry in their bodies may develop resistance to fluoroquinolones, potentially limiting the usefulness of these drugs as empiric therapy. Doxycycline is less frequently used for empiric treatment than ciprofloxacin; therefore, we have fewer concerns regarding this drug and the emergence of new resistant bacteria.

Why are people who have been exposed to B. anthracis being given antibiotics for different amounts of time?
The initial number of people placed on prophylaxis may reflect conservative estimates with wide safety margins based on limited preliminary information. As the investigation progresses, and a clearer picture of exposure develops, the number of people advised to continue prophylaxis may be reduced. As of the last week of October 2001, when preliminary tests show that people have been exposed to Bacillus anthracis, those exposed may be provided with a starter packet of antibiotics; the number of days for which antibiotics are prescribed can vary according to the specific situation and person. Additional tests are then conducted of the area where exposure occurred and to determine the extent of exposure. Based on the results of these additional tests, those exposed may be instructed to return to a centralized location for additional care or to seek additional care from their primary care providers; additional antibiotics may be prescribed based on the particular situation and person. Lastly, it is recommended that people found to be at risk of inhalation anthrax be prescribed 60 days of antibiotics. These general procedures may change at any time as new information is gathered.

Are there different strains of B. anthracis? Do they all respond to antibiotics?
Yes, there are different strains of Bacillus anthracis. Some strains of B. anthracis may be naturally resistant to certain antibiotics and not others. In addition, there may be biologically mutant strains that are engineered to be resistant to various antibiotics. A laboratory analysis can help to define which strain of B. anthracis is present and which antibiotic would be the most effective in treating the resulting anthrax.

What is the FDA telling physicians and other health professionals about prescriptions for ciprofloxacin?
Although FDA does not regulate the practice of medicine, the agency is strongly recommending that physicians not prescribe ciprofloxacin for individual patients to have on hand for possible use against inhaled anthrax. Indiscriminate and widespread use of ciprofloxacin could hasten the development of drug-resistant organisms and lessen the effects of these agents against many infections.

Can other fluoroquinolones be used instead of ciprofloxacin for postexposure prophylaxis (PEP)/treatment?
Other fluoroquinolones, such as ofloxacin and levofloxacin, are not specifically recommended as alternatives to ciprofloxacin because of a lack of sufficient data on their efficacy. However, if first-line drugs were not available, these other fluoroquinolones may be effective.

Why do I need 60 days of antibiotics?
Anthrax spores grow like plant seeds. If you plant seeds and give them sun and water, they will grow into plants. If you give anthrax spores the right environment, such as the human body, they can grow into the harmful form of the bacteria that can cause anthrax disease. It takes anthrax spores an average of 7 days to grow into the harmful form of the bacteria, but it can take longer. For this reason, you must continue taking preventive antibiotics for the full 60 days.

What happens if I take ciprofloxacin, doxycycline, or amoxicillin for a few days, stop, and then restart the antibiotics?
You should complete the 60-day course of antibiotics that you were given. It is best to take antibiotics as prescribed and not to skip any doses.

The ciprofloxacin I am taking gives me headaches. Is there anything I can do to help this?
If you don’t have a history of headaches, then your headache may be related to the medicine. Changing the time of day that you take the ciprofloxacin or eating after you take the medicine may help. Pain relievers such as acetaminophen may help your headache. If your headache does not go away, you should consult your doctor.

The ciprofloxacin, doxycycline, or amoxicillin I am taking makes me feel sick to my stomach. Is there anything I can do to help this?
Taking your antibiotic with food may help reduce this sick feeling. Ciprofloxacin and doxycycline should not be taken within 2 hours of taking antacids. Ciprofloxacin and doxycycline should not be taken with dairy or calcium-fortified products (such as ice cream or calcium-fortified orange juice).

The ciprofloxacin, doxycycline, or amoxicillin I am taking gives me diarrhea. Is there anything I can do to help this?
Antibiotics may disrupt bacteria in the gastrointestinal tract, causing diarrhea. Food may help relieve the diarrhea. If the diarrhea does not go away, your doctor may recommend another antibiotic. If you develop severe, long-lasting diarrhea, you may have a serious condition and should consult your doctor.

If taking one of the recommended antibiotics makes me feel terrible, can I switch to another of these antibiotics?
If you have tried taking the medicine with food or changing the time of your dose but still feel terrible, you should ask your doctor about switching antibiotics.

I am having terrible yeast infections while taking ciprofloxacin, doxycycline, or amoxicillin. Is there anything I can take for this?
Occasionally, women develop yeast infections while taking amoxicillin. You may treat the infection with over-the-counter medicines such as clotrimazole. If the symptoms do not go away, you should consult your doctor.

I feel much better if I take only one pill of ciprofloxacin, doxycycline, or amoxicillin each day. Is that okay?
No. The drug must be taken twice a day to kill the bacteria. If your body contains anthrax bacteria and you do not take the full dose, the bacteria may start to grow again and become harder to kill.

My prescription says to take one pill every 12 hours. If 15 hours have passed since my last dose, is it still okay to take the pill?
Yes. It is okay to take the next pill even if 15 hours have elapsed. However, you should not make a habit of this. The medicine works best when taken every 12 hours.

What side effects are serious enough that I should go to a doctor?
Any side effect that forces you not to take your medicine is serious enough that you should consult or see your doctor. Serious side effects of ciprofloxacin include seizures, mental confusion, rash that does not go away, or excessive diarrhea. If you have any of these effects, call your doctor.

Serious side effects of doxycycline include jaundice (yellow eyes or skin), rash that does not go away, or excessive diarrhea. If you have any of these effects, call your doctor.

Any reaction that causes a rapid swelling of the lips and face, shortness of breath, or hives is a medical emergency. You should call 911. These types of reactions are extremely rare.

Can I drink alcohol if I am taking ciprofloxacin, doxycycline, or amoxicillin?
Social drinking of alcohol (fewer than 2 drinks a day) should not cause any side effects unless you already have a liver problem. However, drinking too much alcohol can cause the medicine to leave your body faster, which will decrease the effectiveness of the medicine. If you drink more than two drinks a day, you should tell your doctor so that different medicines can be prescribed.

The ciprofloxacin, doxycycline, or amoxicillin I am taking makes me feel itchy all over. Is there anything I can do to help this?
Rashes that appear suddenly or do not go away after a few days may be signs of an allergic reaction. You should see your doctor immediately.

The ciprofloxacin, doxycycline, or amoxicillin gave me an allergic reaction and I stopped taking it. What should I do?
If the allergic reaction was severe or rapid, you should notify your doctor before taking another antibiotic. Your doctor will prescribe a different antibiotic that will kill the bacteria without causing an allergic reaction. Remember: you should complete the entire 60 days of treatment even if you change antibiotics.

Why can’t I take a shot, wear a patch, or take one large dose of the medicine instead of taking it for 60 days?
Spores can stay in your body for some time before they start growing and causing you to become ill. When the spores are not growing, antibiotics are not effective. Only after the spores start to grow can the antibiotics work. Therefore, you need a constant level of antibiotic in your body for 60 days to make sure that when the spores start to grow, the antibiotic is there to kill them.

Ciprofloxacin and doxycycline look different and come in different doses. Is one better than the other?
Ciprofloxacin 500 mg and doxycycline 100 mg both have the same killing power in your bloodstream and are equally effective against anthrax bacteria. Doxycycline is available in both tablet and capsule form. Both will give you the same amount of medicine in your bloodstream to kill the bacteria.

Should all patients who have flu-like symptoms be treated with antibiotics?
No. CDC does not recommend treating all patients who have flu-like illness with antibiotics. Antibiotics do not kill viruses, which cause the flu. If the patient is not at risk for developing anthrax, antibiotics are not recommended because the person may experience serious side effects. Also, taking antibiotics can increase the chance that the medicine will not be as effective against other bacterial infections.

Does a patient have immunity after recovering from anthrax infection?
We do not have enough data at this time to make this determination. However, it is theoretically possible to gain post-infection immunity.

How do doctors treat inhalational anthrax to reduce the risk of death in patients?
When inhalational anthrax is suspected, physicians prescribe antibiotics to treat the disease. To be effective, antibiotic therapy should be initiated as soon as possible after exposure. Other treatment includes supportive care in hospital. B. anthracis usually responds effectively to several antibiotics including penicillin, doxycycline, and fluoroquinolones (such as ciprofloxacin).

I was told that I had been exposed to Bacillus anthracis and prescribed antibiotics. I took the medicine for a couple weeks. Wouldn’t that weaken any anthrax that’s in my body?
You should take the full 60 days of antibiotics even if you feel better. Inhaled anthrax spores become lodged in the body and may activate after initial exposure. Antibiotics have little or no effect when the spores are inactive. To be effective in preventing inhalational anthrax, the antibiotics must be in your system when the spores activate. It is necessary to take the medicine for at least 60 days to ensure the best protection against inhalational anthrax.

Why was ciprofloxacin ever publicized as the best drug for anthrax? How can we know which antibiotic is best?
At the beginning of the recent anthrax outbreak, investigators did not know which drugs would kill the strains of Bacillus anthracis responsible for the outbreak. They used ciprofloxacin because very few bacteria are resistant to it. Recent laboratory tests using all of the B. anthracis strains from the recent outbreak have indicated that all the strains are susceptible to ciprofloxacin, doxycycline, and other antibiotics.

Besides anthrax, what else is ciprofloxacin prescribed for? Has there been resistance to ciprofloxacin when used in other instances (historically)?
Ciprofloxacin is a broad-spectrum, highly effective antibiotic that has been part of the “international traveler’s” kit at CDC for at least a year. It can be used against most bacterial infections. However, ciprofloxacin is frequently overused for many diseases that can be treated with less powerful, narrower-spectrum drugs. Right now, most bacteria are susceptible to ciprofloxacin, which is why we want to be cautious about its use. Overuse of ciprofloxacin could lead to the development of resistance.

Is there a generic form of ciprofloxacin?
No, there is currently no generic form of ciprofloxacin in the United States.