Antibiotic-associated diarrhea and colitis is affecting more of you, given the widespread use of antibiotics. Clostridium difficile (C. diff) is the organism that causes antibiotic-associated colitis; this happens because the bacteria is allowed to overgrow in the intestine when the normal intestinal flora is changed due to antibiotics. C. diff can release toxins that bind to receptors on intestinal epithelial cells causing inflammation (colitis) and diarrhea. This makes folks very sick.
Some antibiotics lead to C. diff much more often than others. When there are options for choice of antibiotic for your infection, err on the side of safety with less C. diff risk. Here’s what you need to know:
The Losers. These antibiotics are most frequently associated with C. diff diarrhea.
- Levofloxacin (Levaquin) is prescribed for bacterial sinusitis, urinary tract infection (UTI), prostatitis, and community-acquired pneumonia among other things. A convenient once-daily broad spectrum antibiotic is appealing, but it is more likely to cause C. diff than other antibiotics.
- Ciprofloxacin (Cipro) is very similar to levofloxacin, though it’s taken twice daily and is most often used for UTI and diabetic foot or bone infections.
- Moxifloxacin (Avelox) is another from the same class of antibiotics as Cipro and Levaquin. It’s prescribed for sinusitis and community-acquired pneumonia.
- Clindamycin (Cleocin) is prescribed for skin and soft tissue infections due to Methicillin-resistant Staph Aureus (MRSA), bite wounds, impetigo, and dental prophylaxis in those allergic to penicillin. It’s cheap and has been around forever, but it’s a known culprit in C. diff diarrhea.
- Cephalosporins like Omnicef (cefdinir), Ceftin (cefuroxime), and Suprax (cefixime) are broad spectrum antibiotics used for pharyngitis (sore throat), sinusitis, and ear infections. They also make the list for the antibiotics most frequently implicated in C. diff infections.
The Winners. These antibiotics are rarely associated with C. diff diarrhea.
- Doxycycline (brand names Oracea, Vibramycin) is an antibiotic prescribed for a wide variety of medical conditions including Lyme disease, bacterial sinusitis, chlamydia infection, rosacea, acne, or skin and soft tissue infections. It’s shown to cause nausea and upset stomach in only 8% of folks taking it. Pro tip: doxycycline monohydrate is easier on the stomach than doxycycline hyclate, and it’s essentially the same antibiotic. The difference is just the “salt” attached to it (monohydrate vs hyclate).
- Metronidazole (Flagyl) is an antibiotic that is actually used to TREAT C. diff infections. Pro tip: Think of metronidazole as an antibiotic primarily for infections from the waist down: sexually transmitted infections like trichomoniasis, pelvic inflammatory disease, C. diff diarrhea, diverticulitis, and bacterial vaginosis.
- Minocycline (brand names Solodyn, Minocin) is a tetracycline antibiotic similar to doxycycline that has limited use. It’s prescribed primarily for acne and treatment of STD infections.
Second Place. These are better than the worst, but not as good as the winners.
- Azithromycin (Zithromax, the “Z-Pack”) has many uses including sinusitis, strep throat, chlamydia and other STD infections, community-acquired pneumonia, and H. pylori, among others. It’s the jack-of-all-trades antibiotic, and there is very little bacterial resistance to azithromycin, making it a popular choice.
- Clarithromycin (Biaxin), like Zithromax, is also used for a number of illnesses including bacterial bronchitis, sinusitis, and skin infections. Pro tip: Almost 10% of you taking it may notice alteration in taste (dysgeusia), especially a metallic taste.
- Sulfamethoxazole/trimethoprim (Bactrim) is most often prescribed for urinary tract infections (UTI or cystitis), skin and soft tissue infections from MRSA, and travelers diarrhea. Pro tip: Don’t count on Bactrim for UTI treatment in areas of the country where there is greater than 20% resistance of E. coli (Los Angeles, for example), and if you’ve used it in the previous 3 months for UTI make another choice.
Honorable Mention. These antibiotics are not frequently associated with C. diff, but are primarily IV (not oral) medications.
- Vancomycin. While Vancomycin does come in a pill form, it is poorly absorbed from the gut so is ONLY indicated as a pill for the treatment of C. diff infection. So yes, oral vancomycin is prescribed for C. diff when metronidazole hasn’t worked. Vancomycin IV is used for treatment of many serious infections though, including sepsis, meningitis, bone infections (osteomyelitis), joint infections, and pneumonias.
- Gentamicin. If you are hospitalized with pneumonia, endocarditis, or a severe kidney infection you may be given Gentamicin IV, but its use is limited due to risk of kidney and ear (ototoxicity) damage.
- Tobramycin is prescribed as an inhaled solution or in IV form for patients with cystic fibrosis, as it is also poorly absorbed by the GI tract. Not all that helpful as on option if you are sick, unless you are hospitalized.
- Amikacin is used for hospital-acquired pneumonias, meningitis, and infections in cystic fibrosis patients so you will not see infections in the community treated with this antibiotic.
Hope this helps.