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Doxycycline (Doxycycline Hyclate) - Summary



Doxycycline is an antibacterial drug synthetically derived from oxytetracycline, and is available as Doxycycline Hyclate Capsules and Tablets for oral administration.

To reduce the development of drug-resistant bacteria and maintain effectiveness of Doxycycline Hyclate Capsules and other antibacterial drugs, Doxycycline Hyclate Capsules should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.


Doxycycline is indicated for the treatment of the following infections:

  • Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox, and tick fevers caused by Rickettsiae.
  • Respiratory tract infections caused by Mycoplasma pneumoniae.
  • Lymphogranuloma venereum caused by Chlamydia trachomatis.
  • Psittacosis (ornithosis) caused by Chlamydophila psittaci.
  • Trachoma caused by Chlamydia trachomatis, although the infectious agent is not always eliminated, as judged by immunofluorescence.
  • Inclusion conjunctivitis caused by Chlamydia trachomatis.
  • Uncomplicated urethral, endocervical, or rectal infections in adults caused by Chlamydia trachomatis.
  • Nongonococcal urethritis caused by Ureaplasma urealyticum.
  • Relapsing fever due to Borrelia recurrentis.

Doxycycline is also indicated for the treatment of infections caused by the following gram-negative microorganisms:

  • Chancroid caused by Haemophilus ducreyi.
  • Plague due to Yersinia pestis.
  • Tularemia due to Francisella tularensis.
  • Cholera caused by Vibrio cholerae.
  • Campylobacter fetus infections caused by Campylobacter fetus (formerly Vibrio fetus).
  • Brucellosis due to Brucella species (in conjunction with streptomycin).
  • Bartonellosis due to Bartonella bacilliformis.
  • Granuloma inguinale caused by Calymmatobacterium granulomatis.

Because many strains of the following groups of microorganisms have been shown to be resistant to doxycycline, culture and susceptibility testing are recommended.

Doxycycline is indicated for treatment of infections caused by the following gram-negative bacteria, when bacteriologic testing indicates appropriate susceptibility to the drug:

  • Escherichia coli.
  • Enterobacter aerogenes (formerly Aerobacter aerogenes).
  • Shigella species.
  • Acinetobacter species.
  • Respiratory tract infections caused by Haemophilus influenzae.
  • Respiratory tract and urinary tract infections caused by Klebsiella species.

Doxycycline is indicated for treatment of infections caused by the following gram-positive microorganisms when bacteriologic testing indicates appropriate susceptibility to the drug:

  • Upper respiratory infections caused by Streptococcus pneumoniae (formerly Diplococcus pneumoniae).
  • Anthrax due to Bacillus anthracis, including inhalational anthrax (post-exposure): to reduce the incidence or progression of disease following exposure to aerosolized Bacillus anthracis.

When penicillin is contraindicated, doxycycline is an alternative drug in the treatment of the following infections:

  • Uncomplicated gonorrhea caused by Neisseria gonorrhoeae.
  • 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.

In acute intestinal amebiasis, doxycycline may be a useful adjunct to amebicides.

In severe acne, doxycycline may be useful adjunctive therapy.


Doxycycline is indicated for the prophylaxis of malaria due to Plasmodium falciparum in short-term travelers (<4 months) to areas with chloroquine and/or pyrimethamine-sulfadoxine resistant strains. (See DOSAGE AND ADMINISTRATION section and Information for Patients subsection of the PRECAUTIONS section.)

See all Doxycycline indications & dosage >>


Published Studies Related to Doxycycline

Effect of doxycycline vs placebo on retinal function and diabetic retinopathy progression in mild to moderate nonproliferative diabetic retinopathy: a randomized proof-of-concept clinical trial. [2014]
IMPORTANCE: Microglia have been associated with inflammatory changes underlying diabetic retinopathy. OBJECTIVE: To investigate whether low-dose oral doxycycline monohydrate, a drug capable of inhibiting microglial activation, can improve or slow the deterioration of retinal function and whether it can induce regression or slow progression of diabetic retinopathy in patients with mild to moderate nonproliferative diabetic retinopathy (NPDR)...

The effect of prolonged systemic doxycycline therapy on serum tissue degrading proteinases in coronary bypass patients: a randomized, double-masked, placebo-controlled clinical trial. [2014]
biomarkers during 4 months of doxycycline therapy in coronary bypass patients... CONCLUSIONS: Doxycycline decreases the systemic inflammatory burden in patients

Subantimicrobial-dose doxycycline treatment increases serum cholesterol efflux capacity from macrophages. [2013]
removal from macrophages... CONCLUSIONS: Our results suggest that SDD treatment may reduce the risk of

A study of the clinical activity of a gel combining monocaprin and doxycycline: a novel treatment for herpes labialis. [2012]
doxycycline in vivo against herpes labialis... CONCLUSION: Combining monocaprin with low-dose doxycycline offers an effective

Low-Dose Doxycycline Plus Additional Therapies may Lower Systemic Inflammation in Postmenopausal Women with Periodontitis. [2011.12]
ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: The effect of subantimicrobial-dose-doxycycline periodontal therapy on serum biomarkers of systemic inflammation: a randomized, double-masked, placebo-controlled clinical trial.

more studies >>

Clinical Trials Related to Doxycycline

NGU: Doxycycline (Plus or Minus Tinidazole) Versus Azithromycin (Plus or Minus Tinidazole) [Completed]
This study will look at the safety, effectiveness, and tolerability of combination medications for the initial treatment of non-gonococcal urethritis (NGU). NGU is inflammation of the tube that carries urine from the bladder. NGU is caused by bacteria that may be passed from person to person during sex. This study will compare the 2 currently recommended NGU treatments, doxycycline and azithromycin, taken with tinidazole (another medication to treat certain sexually transmitted infections). Tinidazole used with doxycycline or azithromycin may cure NGU better than when doxycycline or azithromycin is used alone. Study participants will be 300 men ages 16-45 years with NGU attending sexually transmitted disease clinics in Birmingham, AL; New Orleans, LA; Durham, NC; and Baltimore, MD. Study participation will last 7 weeks and involve 3 visits. At each visit, participants will provide a urine sample, have 2 urethral swabs, and have their urethra checked for discharge indicating infection.

Doxycycline Treatment to Prevent Progressive Coronary Artery Dilation in Children With Kawasaki Disease [Not yet recruiting]
Kawasaki disease (KD) affects infants and young children causing inflammation of the skin and blood vessels including the coronary arteries of the heart. Despite the currently available therapy, about one third of children develop enlargement of the coronary arteries that can lead to serious complications such as coronary artery stenosis, heart attack and even death. Kawasaki disease is the most common heart disease in children in the USA and it is especially common among the children of Hawaii. Every year, 50-90 children are diagnosed with KD in Hawaii and unfortunately there is no medication available to successfully prevent coronary artery damage in a subset of cases. During the first few weeks of the illness, cells of the immune system attack the coronary arteries and release a special substance (MMP) that is responsible for the coronary artery enlargement. There is a common antibiotic, doxycycline that can specifically block the action of this special substance (MMP). Research done on animals with KD showed that doxycycline was able to block this special substance and prevent enlargement of coronary arteries. Research in adults with enlargement of the main artery in their abdomen also showed that doxycycline may improve the outcome. Based on these studies doxycycline may be a promising therapy for children with KD, who develop enlargement of the coronary arteries. The investigators' proposed research study will assess the usefulness of doxycycline in preventing the progressive enlargement of coronary arteries in children with KD. The investigators plan to perform a small (pilot) study to evaluate how good is doxycycline in preventing coronary artery enlargement. The investigators will treat 25 children with KD and enlarged coronary arteries for two weeks with doxycycline and assess the change in coronary arteries as well as the blood levels of the special substance (MMP). If doxycycline proves to be beneficial in this small study, the investigators are going to design a large research study involving multiple institutions on Hawaii and the mainland and will recruit more children to be certain about the value of the proposed treatment. The investigators' proposal may change the treatment protocol of KD and could present a possible treatment for children with enlarged coronary arteries preventing potentially devastating consequences.

Effectiveness of Doxycycline for Treating Pleural Effusions Related to Cancer in an Outpatient Population [Recruiting]
Patients with cancer may experience problems with their breathing due to a fluid accumulation around their lungs called malignant pleural effusion (MPE). This fluid can be drained but draining may not stop the fluid from accumulating again. MPE can cause shortness of breath during activity and at rest leaving patients feeling as though they cannot catch their breath enough to be comfortable. Other symptoms can include pain, cough and weight loss. One way to stop the fluid from accumulating is to create scar tissue between the lung and chest wall so there is no more room for fluid accumulation. This procedure is called pleurodesis. Pleurodesis is the standard of care at most centres across Canada. This procedure is done by injecting a drug into the space between the lung and chest wall through a catheter, Doxycycline is one of the drugs currently used for this purpose. Traditionally, patients are admitted for pleurodesis, mostly because the size of the catheter used to inject the medication is very large but also because of the potential complications that can happen with these larger chest tubes. At our centre, most patients with MPE are managed at home with a smaller sized catheter known as a Pleurx catheter. The Pleurx catheter allows patients to remain at home for treatment and trained staff come into the home to both drain the MPE and monitor the patient. Sometimes, patients experience pleurodesis through use of the Pleurx catheter alone. Pleurodesis with doxycycline can happen faster than with the Pleurx catheter alone. It has been our experience with a limited number of patients that it is safe to perform pleurodesis using the Pleurx catheter for doxycycline injection in an outpatient setting.

Examination of the Anti-inflammatory and Insulin Sensitizing Properties of Doxycycline in Humans [Completed]
Obesity is a heightened state of inflammation in which production of cytokines and matrix metalloproteinases (MMPs) result in loss of function of insulin receptors and insulin resistance. Doxycycline (DOX) is a potent MMP inhibitor. We hypothesize that DOX will enhance insulin sensitivity and decreases inflammation in obese participants with type 2 diabetes (DM2).

Doxycycline in Therapy of Erythema Migrans [Recruiting]
The investigators will compare the outcome of three groups of erythema migrans patients treated with doxycycline: a group without any accompanying symptoms, with mild symptoms and with severe symptoms that require lumbar puncture.

more trials >>

Reports of Suspected Doxycycline Side Effects

Rash (32)Vomiting (20)Renal Failure Acute (16)Pruritus (15)Interstitial Lung Disease (14)Oesophageal Ulcer (13)Hyperkalaemia (12)Headache (12)Drug Hypersensitivity (12)Foreign Body (12)more >>


Based on a total of 38 ratings/reviews, Doxycycline has an overall score of 6.74. The effectiveness score is 7.74 and the side effect score is 7.21. The scores are on ten point scale: 10 - best, 1 - worst. Below are selected reviews: the highest, the median and the lowest rated.

Doxycycline review by 37 year old female patient

Overall rating:  
Effectiveness:   Highly Effective
Side effects:   Mild Side Effects
Treatment Info
Condition / reason:   pneumonia
Dosage & duration:   100 mg taken bid for the period of 10 days
Other conditions:   none
Other drugs taken:   none
Reported Results
Benefits:   fast onset of action. quicker than a zpak with is erythromycin. for 5 days. Onset of action is faster and patient starts to feel better in two days versus a week.
Side effects:   mild nausea, mild stomach irritation, can develop yeast infection for can you can counter these effects by taking a little food by mouth with the antibiotics however the food cannot be dairy. Also to counter the possibility an yeast infection eat yogurt but only 1 hour before taking the pills or 2 hours after taking the pills
Comments:   take by mouth twice daily for 10 days


Doxycycline review by 24 year old male patient

Overall rating:  
Effectiveness:   Highly Effective
Side effects:   Mild Side Effects
Treatment Info
Condition / reason:   Clamydia
Dosage & duration:   2 tablets a day taken twice a day for the period of 10 days
Other conditions:   acne
Other drugs taken:   None
Reported Results
Benefits:   My chlamydia went a way and i made a complete recovery. My acne also temporarily went away, which was good. However, it did come back after i stopped taking it, which meant it was somewhat useless.
Side effects:   I had diahrea and some stomach upsets....While i wasn't taking it for my acne, it seemed to have helped it. However, the Diahrea is something i've had with most antibiotics. I countered it by having acidophilus supplements, which worked really well.
Comments:   None i can describe, just took two tablets a day. One before breakfast and one before dinner. The treatment lasted ten days and i took it religiously. I did have to take other acidophilus containing products to control the side effects but it was fortunate that it lasted only 10 days.


Doxycycline review by 32 year old female patient

Overall rating:  
Effectiveness:   Ineffective
Side effects:   Severe Side Effects
Treatment Info
Condition / reason:   mastitis
Dosage & duration:   50 mg taken twice a day for the period of only 3-4 days because of side effects
Other conditions:   none
Other drugs taken:   ibuprophen for pain
Reported Results
Benefits:   None because I had to stop taking it due to the side effects.
Side effects:   Severe abdominal spasms/pain and diarrhea
Comments:   Was supposed to take it to clear up my mastitis but couldn't complete the treatment because my abdominal pain was too severe. I was changed to a different antibiotic.

See all Doxycycline reviews / ratings >>

Page last updated: 2015-08-10

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