Administration by mouth, and intravenously.
Bioavailability 100%
Protein binding 90%.
Hepatic metabolism.
Biological half-life 15–25 hours.
Excretion urine at 40%.
An antibiotic that is used in the treatment of a number of types of infections caused by bacteria and protozoa.
It is useful for bacterial pneumonia, acne, chlamydia infections, early Lyme disease, cholera and syphilis.
It is also useful for the treatment of malaria when used with quinine and for the prevention of malaria.
Common side effects include diarrhea, nausea, vomiting, a red rash, and an increased risk of a sunburn.
If used during pregnancy or in young children may result in permanent problems with the teeth including changes in their color.
Use during breastfeeding is probably safe.
A broad-spectrum antibiotic of the tetracycline class.
Kills bacteria and protozoa by inhibiting protein production.
Pregnancy category D
Generic 100 mg doxycycline capsules.
Frequently used to treat Lyme disease, chronic prostatitis, sinusitis, pelvic inflammatory disease, acne, rosacea, and rickettsial infections.
It is used in prophylaxis against malaria, bit it is not be used alone for initial treatment of malaria, because its antimalarial effect is delayed related to its mechanism of action, which is to specifically impair cell division.
Moraxella catarrhalis, Brucella melitensis, Chlamydia pneumoniae, and Mycoplasma pneumoniae are generally susceptible to doxycycline.
Some Haemophilus spp., Mycoplasma hominis, and Pseudomonas aeruginosa have developed resistance to doxycline.
It is used in the treatment and prophylaxis of anthrax and Leptospirosis.
It is effective against Yersinia pestis the infectious agent of bubonic plague.
It is prescribed for the treatment of Lyme disease,mehrlichiosis and Rocky Mountain spotted fever.
Indicated for treatment of:
Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever rickettsialpox, and tick fevers caused by Rickettsia.
Respiratory tract infections caused by Mycoplasma pneumoniae.
Lymphogranuloma venereum, trachoma, inclusion conjunctivitis, and uncomplicated urethral, endocervical, or rectal infections in adults caused by Chlamydia trachomatis.
Psittacosis caused by Chlamydia psittaci
Nongonococcal urethritis caused by Ureaplasma urealyticum
Relapsing fever due to Borrelia recurrentis
Chancroid caused by Haemophilus ducreyi
Plague due to Yersinia pestis
Tularemia due to Francisella tularensis
Cholera caused by Vibrio cholerae
Campylobacter fetus infections
Brucellosis caused by Brucella species
Bartonellosis caused by Bartonella bacilliformis
Granuloma inguinale caused by Calymmatobacterium granulomatis
Lyme disease caused by Borrelia burgdorferi
When bacteriologic testing indicates appropriate susceptibility to the drug, doxycycline may be used to treat these infections caused by Gram-negative bacteria
Escherichia coli infections
Enterobacter aerogenes infections
Shigella species infections
Acinetobacter species infections.
Respiratory tract infections caused by Haemophilus influenzae
Respiratory tract and urinary tract infections caused by Klebsiella species.
Some Gram-positive bacteria have developed resistance to doxycycline including: Streptococcus pyogenes S. faecalis
When bacteriologic testing indicates appropriate susceptibility to the drug, doxycycline may be used to treat these infections caused by Gram-positive bacteria.
Upper respiratory infections caused by Streptococcus pneumoniae.
Skin and soft tissue infections caused by Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus infections.
Anthrax caused by Bacillus anthracis infection
When penicillin is contraindicated, it can be used to treat:
Syphilis caused by Treponema pallidum
Yaws caused by Treponema pertenue
Listeriosis due to Listeria monocytogenes
Vincent’s infection caused by Fusobacterium fusiforme
Actinomycosis caused by Actinomyces israelii
Infections caused by Clostridium species.
May also be used as adjunctive therapy for severe acne.
It is the first-line for treatment brucellosis is combination of streptomycin and the second-line is combination with rifampin
It kills the symbiotic Wolbachia bacteria in the reproductive tracts of parasitic filarial nematodes, making the nematodes sterile, and thus reducing transmission of diseases such as onchocerciasis and elephantiasis.
Used to treat sexually transmitted, respiratory, and ophthalmic infections.
Representative pathogenic genera include Chlamydia, Streptococcus, Ureaplasma, Mycoplasma, and others.
MIC susceptibility data for a few medically significant microorganisms.
Chlamydia psittaci: 0.03 μg/ml
Mycoplasma pneumoniae: 0.016 μg/ml – 2 μg/ml
Streptococcus pneumoniae: 0.06 μg/ml – 32 μg/ml[31]
Cautions and side effects are similar to those of other members of the tetracycline antibiotic group.
An erythematous rash in sun-exposed parts of the body has been reported to occur in 7.3–21.2%, and the rash resolves upon discontinuation of the drug.
It may be used in those with renal impairment.
Contraindicated in the pediatric treatment of acute bacterial rhinosinusitis.
The combination of doxycycline with dairy, antacids, calcium supplements, iron products may decrease effectiveness.
Breakfast was observed to reduce doxycycline absorption significantly.
Absorption occurs in the stomach and the upper small intestine.
Absorption impaired by milk products, aluminum hydroxide gels, sodium bicarbonate, calcium and magnesium salts, laxatives containing magnesium and iron preparations.
The mechanisms responsible for decreased absorption appear to be chelation and an increase in gastric pH, so it is advisable to take on an empty stomach.
Categorized by the FDA as a class D drug in pregnancy, as it is contraindicated in pregnancy through infancy and childhood up to eight years of age, due to the potential for disrupting bone and tooth development.
Should not be administered to children under the age of eight except in the treatment of anthrax, or where other medications are contraindicated or ineffective.
Crosses into breastmilk.
Doxycycline–metal ion complexes are unstable at acid pH, therefore more doxycycline enters the duodenum for absorption than the earlier tetracycline compounds.
Food has less effect on absorption than on absorption of earlier drugs with doxycycline serum concentrations being reduced by about 20% by test meals compared with 50% for tetracycline.
Doxycycline is to be taken with precaution in patients with kidney injury, as they can worsen azotemia due to catabolic effects.