- Bacterial Infections 101 Pictures Slideshow
- Take the Tummy Trouble Quiz
- Hepatitis C Slideshow Pictures
- Amoxicillin vs. doxycycline: What's the difference?
- What is amoxicillin? What is doxycycline?
- What are the side effects of amoxicillin and doxycycline?
- What is the dosage of amoxicillin vs. doxycycline?
- What drugs interact with amoxicillin and doxycycline?
- Are amoxicillin and doxycycline safe to use while pregnant or breastfeeding?
Amoxicillin vs. doxycycline: What's the difference?
- Amoxicillin and doxycycline are antibiotics used to treat bacterial infections of the respiratory tract and other infections.
- Amoxicillin is also used to treat bacterial infections of the middle ear, tonsils, throat, urinary tract, and skin. It also is used to treat gonorrhea.
- Doxycycline is also used to treat non-gonococcalurethritis (due to Ureaplasma), Rocky Mountain spotted fever, typhus, chancroid, cholera, brucellosis, anthrax, syphilis, acne, and periodontal disease.
- Amoxicillin and doxycycline belong to different antibiotic drug classes. Amoxicillin is a penicillin-type antibiotic and doxycycline is a tetracycline antibiotic.
- Brand names for amoxicillin include Moxatag and Amoxil.
- Brand names for doxycycline include Vibramycin, Oracea, Adoxa, Atridox, Acticlate, Acticlate Cap, Doryx, Doxteric, Doxy, and Monodox.
- Side effects of amoxicillin and doxycycline that are similar include diarrhea or loose stools, abdominal pain, nausea, and vomiting.
- Side effects of amoxicillin that are different from doxycycline include dizziness, heartburn, sleep problems (insomnia), itching, confusion, easy bruising, bleeding, rash, and allergic reactions.
- Side effects of doxycycline that are different from amoxicillin include tooth discoloration if used in persons below 8 years of age and exaggerated sunburn.
What is amoxicillin? What is doxycycline?
Amoxicillin is a penicillin-type antibiotic used to treat bacterial infections of the middle ear, tonsils, throat, larynx (laryngitis), bronchi (bronchitis), lungs (pneumonia), urinary tract, and skin. It also is used to treat gonorrhea. Other penicillin-type antibiotics include ampicillin (Unasyn), piperacillin (Pipracil), and ticarcillin (Ticar). These antibiotics stop bacteria from multiplying by preventing bacteria from forming the walls that surround them that are necessary to protect bacteria from their environment and to keep the contents of the bacterial cell together. Bacteria are unable survive without a cell wall. Amoxicillin is effective against many different bacterial strains including H. influenzae, E. coli, Pneumococci, N. gonorrhoea, Streptococci, and some strains of Staphylococci.
Doxycycline is a tetracycline antibiotic used for many different types of infections, including respiratory tract infections due to Hemophilus influenzae, Streptococcus pneumoniae, or Mycoplasma pneumoniae. It also is used to treat non-gonococcal urethritis (due to Ureaplasma), Rocky Mountain spotted fever, typhus, chancroid, cholera, brucellosis, anthrax, syphilis, acne, and periodontal disease. Doxycycline works by interrupting the production of proteins by bacteria.
What are the side effects of amoxicillin and doxycycline?
Side effects due to amoxicillin include
- abdominal pain,
- easy bruising,
- rash, and
- allergic reactions.
People who are allergic to the cephalosporin class of antibiotics, which are related to the penicillins, for example, cefaclor (Ceclor), cephalexin (Keflex), and cefprozil (Cefzil), may or may not be allergic to penicillins.
Serious but rare reactions include:
- severe allergic reactions (anaphylaxis), and
- low platelet (thrombocytopenia) or red blood cell count.
Amoxicillin can alter the normal bacteria in the colon and encourage overgrowth of some bacteria such as Clostridium difficile which causes inflammation of the colon (pseudomembranous colitis). Patients who develop signs of pseudomembranous colitis after starting amoxicillin (diarrhea, fever, abdominal pain, and possibly shock) should contact their physician immediately.
Doxycycline is generally well-tolerated. The most common side effects are
Tetracyclines, such as doxycycline, may cause tooth discoloration if used in persons below 8 years of age. Exaggerated sunburn can occur with tetracyclines; therefore, sunlight should be minimized during treatment.
Latest Infectious Disease News
Daily Health News
What is the dosage of amoxicillin vs. doxycycline?
- For most infections in adults the dose of amoxicillin is 250 mg every 8 hours, 500 mg every 8 hours, 500 mg every 12 hours or 875 mg every 12 hours, depending on the type and severity of infection.
- For the treatment of adults with gonorrhea, the dose is 3 g given as one dose.
- For most infections, children older than 3 months but less than 40 kg are treated with 25 or 45 mg/kg/day in divided doses every 12 hours or 20 or 40 mg/kg/day with one-third of the daily dose given every 8 hours depending on the type and severity of the infection.
- Amoxicillin can be taken with or without food.
- The absorption of doxycycline is not markedly affected by food, and 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.
What drugs interact with amoxicillin and doxycycline?
Amoxicillin is rarely associated with important drug interactions.
- It is recommended that doxycycline not be taken 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, doxycycline should not be taken 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. It may also reduce the effect of oral contraceptives. Combining tetracycline and methoxyflurane (Penthrane) may reduce kidney function.
Subscribe to MedicineNet's General Health Newsletter
Are amoxicillin and doxycycline safe to use while pregnant or breastfeeding?
- Penicillins are generally considered safe for use by pregnant women who are not allergic to penicillin.
- Small amounts of amoxicillin may be excreted in breast milk and may cause diarrhea or allergic responses in nursing infants. Amoxicillin is generally considered safe to use while breastfeeding. Amoxicillin is used to treat infections in the newborn.
- 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 physician must decide whether to recommend that a nursing mother discontinue nursing during treatment with tetracyclines or change to a different antibiotic.
Amoxicillin (Moxatag, Amoxil) and doxycycline (Doryx, Vibramycin) are antibiotics used to treat bacterial infections of the respiratory tract and other infections. Amoxicillin is also used to treat bacterial infections of the middle ear, tonsils, throat, urinary tract, and skin. It also is used to treat gonorrhea. Doxycycline is also used to treat non-gonococcalurethritis (due to Ureaplasma), Rocky Mountain spotted fever, typhus, chancroid, cholera, brucellosis, anthrax, syphilis, acne, and periodontal disease. • Amoxicillin and doxycycline belong to different antibiotic drug classes. Amoxicillin is a penicillin-type antibiotic and doxycycline is a tetracycline antibiotic.
Multimedia: Slideshows, Images & Quizzes
Bacterial Infections 101: Types, Symptoms, and Treatments
Get more information on bacterial skin infections, which bacteria cause food poisoning, sexually transmitted bacteria, and more....
Ear Infection Symptoms, Causes, and Treatment
Learn about the causes and symptoms of ear infections and how they are diagnosed and treated. Read about treatments such as ear...
MRSA Infection: Causes, Symptoms, and Treatment
MRSA and staph infections are caused by a 'super bug' resistant to antibiotics. Learn causes, symptoms, and treatment options of...
Bladder Infections: UTI Causes, Symptoms, Treatments
Urinary tract infections (UTI), including bladder infections, affect women and men, causing UTI symptoms like kidney infection....
Ear Infection Quiz: Test Your Medical IQ
Is it possible to prevent ear infections? Take the Ear Infection (Otitis Media) Quiz to learn the risks, causes, symptoms and...
Related Disease Conditions
Sinus Infection (Sinusitis)
Sinus infection (sinusitis) is caused by allergies, infection, and chemicals or other irritants of sinuses. Signs and symptoms are headache, fever, and facial tenderness, pressure, or pain. Treatments of sinus infections are generally with antibiotics and at times, home remedies.
Inner Ear Infection (Symptoms, Signs, Treatments, Home Remedies)
An inner ear infection or otitis interna is caused by viruses or bacteria and can occur in both adults and children. An inner ear infection can cause symptoms and signs, for example, a severe ear, dizziness, vertigo, nausea and vomiting, and vertigo. An inner ear infection also may cause inflammation of the inner ear or labyrinthitis. Inner ear infections are not contagious; however, the bacteria and viruses that cause the infection can be transmitted to other people. Good hygiene practices will help decrease the chances of the infection spreading to others. Inner ear infection symptoms and signs like ear pain and nausea may be relieved with home remedies or over the counter (OTC) medication. Some inner ear infections will need to be treated and cured with antibiotics or prescription pain or antinausea medication.
Staph (Staphylococcus) Infection
Staphylococcus or staph is a group of bacteria that can cause a multitude of diseases. Staph infections can cause illness directly by infection or indirectly by the toxins they produce. Symptoms and signs of a staph infection include redness, swelling, pain, and drainage of pus. Minor skin infections are treated with an antibiotic ointment, while more serious infections are treated with intravenous antibiotics.
Ear Infection Home Treatment
Infections of the outer, middle, and inner ear usually are caused by viruses. Most outer (swimmer's ear) and middle ear (otitis media) infections can be treated at home with remedies like warm compresses for ear pain relief, tea tree, ginger, or garlic oil drops. Symptoms of an outer ear (swimmer's ear) and middle ear infection include mild to severe ear pain, pus draining from the ear, swelling and redness in the ear, and hearing problems. Middle and inner ear infections may cause fever, and balance problems. Inner ear infections also may cause nausea, vomiting, vertigo, ringing in the ear, and labyrinthitis (inflammation of the inner ear). Most outer and middle ear infections do not need antibiotics. Inner ear infections should be treated by a doctor specializing in ear and hearing problems.
Middle Ear Infection (Otitis Media)
Middle ear infection (otitis media) is inflammation of the middle ear. There are two forms of this type of ear infection, acute and chronic. Acute otitis media is generally short in duration, and chronic otitis media generally lasts several weeks. Babies, toddlers, and children with a middle ear infection may be irritable, pull and tug at their ears, and experience numerous other symptoms and signs. Treatment depends upon the type of ear infection.
Urinary Tract Infection (UTI)
A urinary tract infection (UTI) is an infection of the bladder, kidneys, ureters, or urethra. E. coli, a type of bacteria that lives in the bowel and near the anus, causes most UTIs. UTI symptoms include pain, abdominal pain, mild fever, urinary urgency and frequency. Treatment involves a course of antibiotics.
Bladder Infection (Cystitis)
Bladder infection is an infection of the bladder, usually caused by bacteria or, rarely, by Candida. Certain people, including females, the elderly, men with enlarged prostates, and those with chronic medical conditions are at increased risk for bladder infection. Bladder infections are treated with antibiotics, but cranberry products and adequate hydration may help prevent bladder infections.
MRSA (methicillin-resistant Staphylococcus aureus) bacteria causes skin infections with the following signs and symptoms: cellulitis, abscesses, carbuncles, impetigo, styes, and boils. Normal skin tissue doesn't usually allow MRSA infection to develop. Individuals with depressed immune systems and people with cuts, abrasions, or chronic skin disease are more susceptible to MRSA infection.
Is a Staph Infection Contagious?
A staph infection is caused by the bacteria Staphylococcus aureus. Staph can cause boils, food poisoning, cellulitis, toxic shock syndrome, MRSA, and various other illnesses and infections. Most staph infections are transmitted from person to person.
Kidney Infection (Pyelonephritis)
Kidney infection (pyelonephritis) usually is caused by E. coli and other bacteria that have spread from the bladder from a UTI (urinary tract infection), poor hygiene, sexual intercourse, pregnancy, catheter, cystoscope exam, surgery, kidney stones, or prostate enlargement. Symptoms of kidney infection include back pain, frequent urination, pain during urination, fever, and or pus or blood in the urine. Kidney infection can be cured with antibiotic treatment. Cranberry juice may prevent UTIs, but that hasn’t been proven in all research studies.
Is a Urinary Tract Infection (UTI) Contagious?
Bacteria such as E. coli or Pseudomonas can cause a urinary tract infection (UTI). The incubation period for a UTI ranges from three to eight days.
Is a Sinus Infection Contagious?
Sinus infection (sinusitis) is infection (viral, bacterial, or fungal) or inflammation of the sinuses. Symptoms of sinus infection are cough, bad breath, coughing up greenish-yellow sputum, sinus headache, and other symptoms of the common cold. Treatments of sinus infection are home remedies to soothe symptoms and antibiotics if the infection is bacterial or fungal.
Group A streptococcal infections are caused by group A Streptococcus, a bacteria that causes a variety of health problems, including strep throat, impetigo, cellulitis, erysipelas, and scarlet fever. There are more than 10 million group A strep infections each year.
Urinary Tract Infections in Children
Urinary tract infections (UTIs) are very common in children. Symptoms and signs include fever and abdominal pain. Associated symptoms and signs include flank pain, vomiting, and blood in the urine. Treatment for a UTI involves antibiotic therapy.
Kidney Infection in Adults
Second Source article from Government
Group A Streptococcal Infections
Second Source article from Government
Treatment & Diagnosis
- Ear Infection FAQs
- What Causes Yeast Infections (Vaginitis)?
- What Is the Difference Between a Bladder Infection vs. UTI?
- How Do You Get Staph Infection?
- What Causes an Ear Infection?
- How Do You Get an Ear Infection?
- How to Get Rid of a Staph Infection
- Flesh Eating Bacterial Infection
- Urinary Tract Infection (UTI) Symptoms
- E. coli Infection Facts
- Urinary Tract Infection (UTI) Treatment
- Air Travel, Colds, and Sinus Infections
Medications & Supplements
Prevention & Wellness
Health Solutions From Our Sponsors
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.