Doxycycline vs. clindamycin

• Doxycycline and clindamycin are antibiotics used to treat many different types of bacterial infections.
• Brand names for doxycycline include Vibramycin, Oracea, Adoxa, Atridox, Acticlate, Acticlate Cap, Doryx, Doxteric, Doxy, and Monodox.
• A brand name for clindamycin is Cleocin.
• Doxycycline and clindamycin are different types of antibiotics. Doxycycline is a tetracycline antibiotic and clindamycin is a lincosamide antibiotic.
• Side effects of doxycycline and clindamycin that are similar include nausea, vomiting, diarrhea, and stomach/abdominal pain.
• Side effects of doxycycline that are different from clindamycin include loose stools, tooth discoloration if used in persons below 8 years of age, and exaggerated sunburn.
• Side effects of clindamycin that are different from doxycycline include unpleasant/metallic taste in mouth, or pain at the injection site, joint pain, vaginal itching or discharge, skin rash or itching, heartburn, sore throat, or changes in bowel habits (especially in older adults).

Doxycycline is a tetracycline antibiotic used to treat many different types of infections, including respiratory tract infections due to Hemophilus influenzae, Streptococcus pneumoniae, or Mycoplasma pneumoniae. It also is used to treat nongonococcal urethritis (due to Ureaplasma), Rocky Mountain spotted fever, typhus, chancroid, cholera, brucellosis, anthrax, syphilis, acne, and periodontal disease.

Clindamycin is a lincosamide antibiotic used to treat a wide variety of bacterial infections. It works by stopping the growth of bacteria. Clindamycin may also be used before dental procedures in patients with certain heart conditions (such as artificial heart valves) to help prevent serious infection of the heart (bacterial endocarditis).

Doxycycline

Doxycycline is generally well tolerated. The most common side effects are:

• Diarrhea or loose stools
• Nausea
• Abdominal pain
• Vomiting

Tetracyclines, such as doxycycline, may cause tooth discoloration if used in persons below 8 years of age.

Exaggerated sunburn can occur with tetracyclines; therefore, minimize exposure to sunlight during treatment.

Clindamycin

The most common side effects of clindamycin are

• Stomach pain
• Diarrhea

Clindamycin also frequently causes

• Nausea
• Vomiting
• Metallic taste
• Low blood pressure
• Rash
• Itching

Clindamycin causes Clostridium difficile-associated diarrhea (CDAD) because it can alter the normal bacteria in the colon and encourage overgrowth of Clostridium difficile, a bacteria which causes inflammation of the colon (pseudomembranous colitis). Patients who develop signs of pseudomembranous colitis after starting clindamycin (diarrhea, fever, abdominal pain, and possibly shock) should contact their doctor immediately.

Other serious side effects of clindamycin include:

• Serious allergic reactions
• Blood disorders
• Stevens-Johnson syndrome
• Toxic epidermal necrolysis

Doxycycline

• The absorption of doxycycline is not markedly affected by food; therefore, it can be taken with meals.
• For most infections, doxycycline is taken once or twice daily for 7 to 14 days.
• For adult infections, the usual dose of oral doxycycline is 200 mg on the first day of treatment (100 mg every 12 hours) followed by a dose of 100 to 200 mg/day as a single dose or divided and administered twice daily.

Clindamycin

• The recommended dose for adults for serious infections is 150 to 450 mg every 6 to 8 hours up to a maximum dose of 1.8 grams per day.
• For pediatric patients, the recommended dose is 8 to 20 mg/kg/day divided into 3 or 4 equal doses.
• To avoid throat irritation, clindamycin should be taken with a full glass of water.

Doxycycline

• Do not take doxycycline at the same time as aluminum-, magnesium-, or calcium-based antacids, such as Mylanta, Maalox, Tums, or Rolaids because, like food, these medications bind doxycycline in the intestine and prevent its absorption. Similarly, do not take doxycycline with minerals (such as calcium or iron) or with bismuth subsalicylate (Pepto Bismol).
• Doxycycline may enhance the activity of warfarin (Jantoven, Coumadin) and cause excessive "thinning" of the blood leading to exaggerated bleeding, necessitating a reduction in the dose of warfarin. Phenytoin (Dilantin), carbamazepine (Tegretol), and barbiturates (such as phenobarbital) may enhance the metabolism (destruction) of doxycycline, thus making it less effective.
• Doxycycline may interfere with the action of penicillins and should not be combined with penicillins. Doxycycline may also reduce the effect of oral contraceptives. Combining tetracycline and methoxyflurane (Penthrane) may reduce kidney function.

Clindamycin

• Clindamycin may act as a neuromuscular blocker. This means it can increase the action of neuromuscular blocking drugs (for example, pancuronium and vecuronium), which are used during surgery.

Doxycycline

• Tetracycline antibiotics, such as doxycycline, can have toxic effects on development of bone in the fetus. Therefore, tetracyclines are not recommended during pregnancy unless there is no other appropriate antibiotic.
• Doxycycline is secreted into breast milk, but the extent of absorption by the breastfed infant is not known. Since tetracyclines can cause toxic effects on bone, the use of tetracyclines in nursing mothers is of concern. The doctor must decide whether to recommend that a nursing mother discontinue nursing during treatment with tetracyclines or change to a different antibiotic.

Clindamycin

• The frequency of congenital abnormalities was not increased when pregnant women used clindamycin during the second and third trimesters. Clindamycin should not be used during the first trimester of pregnancy unless it is clearly needed, because it has not been properly evaluated during the first trimester of pregnancy.
• Clindamycin is excreted in breast milk and should not be used by nursing mothers or nursing should be stopped.