Doxycycline Uses, Dosage, Side Effects, Food Interaction and all others data.

Doxycycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. It has bacteriostatic activity against a broad range of gm+ve and gm-ve bacteria.

The tetracyclines, including doxycycline, are mainly bacteriostatic and are thought to exert antimicrobial effects by the inhibition of protein synthesis. Bacteriostatic antibiotics suppress the growth of bacteria, or keep them in the stationary phase of growth . The tetracyclines, including doxycycline, have a similar antimicrobial spectrum of activity against a variety of gram-positive and gram-negative microorganisms, treating numerous infectious diseases. Cross-resistance of these microorganisms to tetracyclines is a common occurrence . Doxycycline shows favorable intra-cellular penetration, with bacteriostatic activity on a wide range of bacteria . Doxycycline has antiparasitic effects , , . In addition to the above effects, this drug has demonstrated anti-inflammatory actions, which may help to manage inflammatory conditions such as rosacea .

Trade Name Doxycycline
Availability Prescription only
Generic Doxycycline
Doxycycline Other Names Doxiciclina, Doxycyclin, Doxycycline, Doxycyclinum
Related Drugs amoxicillin, prednisone, albuterol, ciprofloxacin, cephalexin, metronidazole, metronidazole topical, azithromycin, clindamycin, clindamycin topical
Weight 100mg,
Type Capsule, Injection, Powder, For Solution, For Oral Suspension
Formula C22H24N2O8
Weight Average: 444.4346
Monoisotopic: 444.153265754
Protein binding

>90% , .

Groups Approved, Investigational, Vet approved
Therapeutic Class Tetracycline Group of drugs
Manufacturer Amros Pharmaceuticals, , Healthcare Pharma Ltd, Kimia Farma, Pyridam Farma, Indofarma, Yarindo Farmatama, Dexa Medica, Sanbe Farma, Shanxi Zhongbao Shuguang Pharm Co Ltd
Available Country Pakistan, United Kingdom, United States, Indonesia, Netherlands, China, Nigeria
Last Updated: September 19, 2023 at 7:00 am


Doxycycline has a very wide spectrum of activities and has been used in the treatment of a large number of infections caused by susceptible organisms.

Respiratory tract infections: Pneumonia, influenza, pharyngitis, tonsillitis, bronchitis, sinusitis, otitis media and other streptococcal and staphylococcal infections where tetracycline resistance is not a problem.

Genitourinary tract infections: Pyelonephritis, cystitis, urethritis, gonorrhea, epididymitis, syphilis, chancroid and granuloma inguinale.

Chlamydia: Lymphogranuloma venereum, psittacosis, trachoma.

Intestinal diseases: Whipples disease, tropical sprue, blind loop syndrome.

In acute intestinal amoebiasis: Doxycycline may be a useful adjunct to amoebicides.

Bacillary infections: Brucellosis, tularemia, cholera, travelers diarrhea

Acne: Acne vulgaris, acne conglobata and other forms of acne.

Other infections: Actinomycosis, yaws, relapsing fever, leptospirosis, typhus, rickettsial pox and Q fever, Cellulitis furunculosis, abscess and infections caused by Mycobacterium marinum, Bordetella pertussis and Bacillus anthracis.

Doxycycline is also used to associated treatment for these conditions: Acinetobacter infection, Acne Rosacea, Actinomycosis, Acute epididymo-orchitis caused by Chlamydia Trachomatis, Anal chlamydia infection, Bacterial Infection caused by Enterobacter aerogenes, Bartonellosis, Brucellosis, Campylobacter Infection, Chancroid, Chlamydial Urethritis, Chlamydial cervicitis, Cholera, Clostridium Infections, Epididymo-orchitis gonococcal, Gonorrhea, Granuloma Inguinale, Infection Due to Escherichia Coli, Intestinal Amebiasis, Listeria infection, Lymphogranuloma Venereum, Necrotizing ulcerative gingivostomatitis, Plague, Plasmodium Infections, Primary Syphilis, Psittacosis, Q Fever, Rectal infection, Rectal infection caused by Chlamydia Trachomatis, Recurring fever caused by Borrelia recurrentis, Relapsing fever caused by Borrelia recurrentis, Respiratory Tract Infections (RTI), Rickettsialpox, Rocky Mountain Spotted Fever, Secondary Syphilis, Severe Acne, Shigella Infection, Skin Infections, Tick-borne fever, Trachoma, Trachoma inclusion conjunctivitis, Tularemia, Typhus Fever, Upper Respiratory Tract Infection, Ureaplasma urethritis, Urinary Tract Infection, Yaws, Inhaled anthrax caused by Bacillus anthracis

How Doxycycline works

In bacterial replication, an interaction that is important for translation initiation of proteins occurs at the 3′ end of the 16S rRNA, found on the ribosome on the 30S subunit , , . The 30S subunit is the smaller subunit of the ribosome of prokaryotes, including bacteria.

Tetracyclines such as doxycycline are thought to inhibit translation by binding to the 16S rRNA portion of the ribosome , preventing binding of tRNA to the RNA-30S bacterial ribosomal subunit, which is necessary for the delivery of amino acids for protein synthesis. As a result of the above actions, the initiation of protein synthesis by polyribosome formation is blocked. This stops the replication of bacteria and produces a bacteriostatic effect .


Doxycycline dosage


Susceptible infections:

  • 200 mg on day 1 as a single or in divided doses, followed by 100 mg once daily. Severe infections: Maintain initial dose throughout the course of treatment.

Relapsing fever and louse-borne typhus:

  • 100 or 200 mg as a single dose.

Prophylaxis of scrub typhus:

  • 200 mg as a single dose.

Uncomplicated gonorrhoea:

  • 100 mg bid for 7 days or a single dose of 300 mg followed by a 2nd similar dose 1 hr later.


  • 100-200 mg bid for at least 14 days.


  • 50 mg daily for 6-12 wk.

Chloroquine resistant falciparum malaria acute attack:

  • 200 mg daily for at least 7 days, w/ or after treatment w/ quinine.

Treatment and postexposure prophylaxis of inhalation anthrax:

  • 100 mg bid, to complete a 60-day course after treatment w/ 1-2 other antibacterials.

Prophylaxis of chloroquine-resistant malaria:

  • 100 mg daily for up to 2 yr.



  • As 10% controlled-release subgingival preparation: Inject the contents of the syringe into the periodontal pocket, may be repeated 4 mth after initial treatment.


Susceptible infections: 200 mg on day 1 followed by 100-200 mg daily depending on the severity of infection.

Side Effects

Gastrointestinal disterbances,eg. anorexia, vomiting, dysentry etc. overgrowth of resistant organisms may cause Glossitis, Stomatitis, or Staphylococcal enterocolitis; Apart from these skin rashes, purpura may occur. Photosensitivity and dermatological reactions are rare.


There are various precautions to be undertaken while doxycyline is administered . A full list of adverse events is included in the "Adverse Effects" section of this drug entry.

A note on tooth development and tetracycline use

The use of tetracyclines, including doxycycline, during tooth development (i.e. the last half of pregnancy, throughout infancy, and in childhood up to 8 years of age) may lead to tooth enamel hypoplasia and yellow-gray discoloration of teeth. It is advisable not to administer doxycycline in this age group according to the FDA label, except for in cases of post-exposure cases of anthrax (including inhalational anthrax) . Other sources state that doxycycline should not be administered in children under 12 years .

A note on Clostridium difficile Clostridium difficile associated diarrhea (CDAD) and antibiotic associated pseudomembranous colitis may result from doxycycline use. Administering antibacterial agents changes the normal flora of the colon leading to an overgrowth of C. difficile. This bacteria produces toxins A and B, which contribute to the development of CDAD . in moderate to severe cases, therapy with a suitable oral antibacterial agent effective against Clostridium difficile should be considered. Fluids, electrolytes and protein replacement should be provided when warranted .

A note on gastrointestinal irritation Gastrointestinal irritation may also occur. Rarely, esophagitis and esophageal ulcers have been reported in patients receiving doxycycline. Most of these patients took medication immediately before going to bed. Administration of appropriate amounts of fluid with the tablets is recommended to reduce the risk of esophageal irritation and ulceration, and late evening ingestion of the dose should be avoided . To decrease the risk of gastric irritation, it is recommended that doxycycline is taken with food or milk. The absorption of doxycycline is not significantly influenced by simultaneous ingestion of food or milk .

Pregnancy Results of animal research indicate that tetracyclines cross the placenta, are found in fetal tissues and exert toxic effects on the developing fetus, manifested by retardation of skeletal development. The importance of this in humans is not known, however, doxycycline should not be used in pregnant women unless the benefit significantly outweighs the risk .

Carcinogenicity In vivo studies conducted in rats and mice have not provided conclusive evidence that tetracyclines may be carcinogenic or that they affect fertility. In two mammalian cell lines, positive tests for mutagenicity occurred at concentrations of 60 and 10 mcg/ml respectively. In humans, no association between tetracyclines and these effects have been established .


During development of teeth (last trimester of pregnency, upto 12 yrs of age) the use of tetracyclines may lead to discoloration of teeth. So tetracyclines should not be administered during these periods


Should not be taken with antacids, milk, other alkalis e.g. calcium, magnesium and iron, penicillin, anticoagulants, anti-diabetic agents, anticonvulsants and enzyme inducing drugs.

Food Interaction

  • Avoid alcohol.
  • Avoid multivalent ions. Calcium, iron, and aluminum containing products taken up to 2 hours before and 6 hours after administration can decrease drug concentrations.
  • Take with a full glass of water.

Doxycycline Alcohol interaction

[Minor] Chronic alcohol consumption may enhance the elimination of doxycycline.

The mechanism is induction of hepatic microsomal enzymes by alcohol.

In one study, the half-life of doxycycline in six alcoholics was 10.5 hours, compared with 14.7 hours in six control patients.

In addition, half the alcoholic patients had serum concentrations below what is generally considered the minimum therapeutic concentration (0.5 mcg/mL) at 12 to 24 hours after the dose.

The investigators suggest that twice-a-day dosing may be indicated in these patients, especially if additional inducing drugs are used.

The elimination of other tetracyclines probably is not affected by alcohol consumption.

Doxycycline multivitamins interaction

[Moderate] GENERALLY AVOID: The bioavailability of oral tetracyclines and iron salts may be significantly decreased during concurrent administration.

Therapeutic failure may result.

The proposed mechanism is chelation of tetracyclines by the iron cation, forming an insoluble complex that is poorly absorbed from the gastrointestinal tract.

In ten healthy volunteers, simultaneous oral administration of ferrous sulfate 200 mg and single doses of various tetracyclines (200 mg to 500 mg) resulted in reductions in the serum levels of methacycline and doxycycline by 80% to 90%, oxytetracycline by 50% to 60%, and tetracycline by 40% to 50%.

In another study, 300 mg of ferrous sulfate reduced the absorption of tetracycline by 81% and that of minocycline by 77%.

Conversely, the absorption of iron has been shown to be decreased by up to 78% in healthy subjects and up to 65% in patients with iron depletion when ferrous sulfate 250 mg was administered with tetracycline 500 mg.

Available data suggest that administration of iron 3 hours before or 2 hours after a tetracycline largely prevents the interaction with most tetracyclines except doxycycline.

Due to extensive enterohepatic cycling, iron binding may occur with doxycycline even when it is given parenterally.

It has also been shown that when iron is administered up to 11 hours after doxycycline, serum concentrations of doxycycline may still be reduced by 20% to 45%.

Coadministration of a tetracycline with any iron-containing product should be avoided if possible.

Otherwise, patients should be advised to stagger the times of administration by at least three to four hours, although separating the doses may not prevent the interaction with doxycycline.

Volume of Distribution

Doxycycline diffuses readily into most body tissues, fluid and/or cavities and the volume of distribution has been measured as 0.7 L/kg .

Elimination Route

Tetracyclines, such as doxycycline, are readily absorbed and are bound to plasma proteins by varying degrees. Doxycycline is almost completely absorbed after oral administration. This drug is highly lipid soluble and has a low affinity for calcium binding . Absorption is not significantly affected by the concomitant ingestion of food or milk . Peak serum levels of approximately 2.6 mcg/ml are reached at 2 hours following a 200 mg tablet oral dose .

Half Life

16.33 hr (± 4.53 sd) .


The excretion of doxycycline by the kidney is about 40% over 72 hours in individuals with normal kidney function (creatinine clearance approximately 75 mL/min). This rate may fall as low as 1-5% over 72 hours in individuals with severe renal insufficiency (creatinine clearance below 10 mL/min). Some clinical studies have shown no major difference in serum half-life of doxycycline (range 18-22 hours) in patients with normal and severely impaired renal function. Hemodialysis does not affect serum half-life of doxycycline .

Elimination Route

Mainly the urine and feces as active and unchanged drug . Between 40% and 60% of an administered dose can be accounted for in the urine by 92 hours, and approximately 30% can be accounted for in the feces .

Pregnancy & Breastfeeding use

Pregnancy: Doxycycline should be avoided in pregnant women, because of the risk of both staining and effect on bone growth in the fetus.

Lactation: Doxycyclines enter breast milk, and mothers taking these drugs should not breastfeed their child.


Hypersensitivity to doxycycline and any of the tetracyclines. Concurrent use with methoxyflurane. Lactation

Special Warning

Neonates and children: Doxycycline may cause permanent discoloration of the teeth and so is contraindicated for neonates and children under 12 years.

Elderly: No special precautions are necessary in the elderly.

Storage Condition

It should be stored in a dry place at room temperature.

Innovators Monograph

You find simplified version here Doxycycline

Doxycycline contains Doxycycline see full prescribing information from innovator Doxycycline Monograph, Doxycycline MSDS, Doxycycline FDA label


What is Doxycycline used for?

Doxycycline is a broad-spectrum tetracycline-class antibiotic used in the treatment of infections caused by bacteria and certain parasites. It is used to treat bacterial pneumonia, acne, chlamydia infections, Lyme disease, cholera, typhus, and syphilis. Doxycycline is also used to prevent malaria in combination with quinine. It's used to treat infections such as chest infections, skin infections, rosacea, dental infections and sexually transmitted infections, as well as a lot of other rare infections. It can also be used to prevent malaria if you're travelling abroad.

How safe is Doxycycline?

Doxycycline is generally well tolerated, especially compared with older tetracyclines and minocycline.

How does Doxycycline work?

Doxycycline works to treat infections by preventing the growth and spread of bacteria.Doxycycline works to treat acne by killing the bacteria that infects pores and decreasing a certain natural oily substance that causes acne.

What are the common side effects of Doxycycline?

    Common side effects of Doxycycline are include:

  • Diarrhea
  • Difficulty swallowing
  • Drug rash
  • Esophageal ulcer
  • Esophagitis
  • Facial redness
  • Headache
  • Hives
  • Inflammation of the small intestine and colon (enterocolitis)
  • Lesions on the genitals or anus
  • Loss of appetite
  • Low blood sugar (hypoglycemia)
  • Low levels of white blood cells or platelets
  • Skin hyperpigmentation
  • Skin peeling (exfoliative dermatitis)
  • Tongue swelling
  • Tooth discoloration
  • Upper abdominal pain

Is Doxycycline safe during pregnancy?

Doxycycline is safe in early pregnancy, possibly throughout pregnancy and for children at the current dosage regimes.

Is Doxycycline safe during breastfeeding?

Doxycycline is excreted into breast milk. Short term use by lactating women is not necessarily contraindicated, however, the effects of prolonged exposure to Doxycycline in breast milk are unknown.

Can I drink alcohol with Doxycycline?

Do not drink alcohol while taking Doxycycline.

What happens if I drink alcohol with Doxycycline?

People should not drink alcohol while taking Doxycycline because this may reduce the effects of the antibiotic. Doxycycline may interact with alcohol. Alcohol speeds up the body's elimination of the Doxycycline and therefore makes it less effective.

Can I drive after taking Doxycycline?

Yes, Doxycycline shouldn't affect you being able to drive or cycle.

When should be taken of Doxycycline?

This Doxycycline is best taken by mouth on an empty stomach, at least 1 hour before or 2 hours after a meal, usually 1 or 2 times daily or as directed by your doctor.

Should Doxycycline be taken morning or night?

Take your Doxycycline during or immediately after a meal, at about the same each day (preferably in the morning). If you take it on an empty stomach, it may cause stomach upset. Avoid taking Doxycycline at bedtime.

When can I take Doxycycline after eating?

You should take this medicine on an empty stomach, preferably at least 1 hour before or 2 hours after meals.

How long does Doxycycline take to work?

Doxycycline may take up to 48 hours before infection-related symptoms start to abate.

How long does Doxycycline stay in my system?

The elimination half life of Doxycycline is between 16 to 22 hours. This is the time it takes for your body to reduce the plasma levels by half. Doxycycline usually takes around 5.5 x elimination half-life (hours) before a drug is completely cleared from your system.

What happens when I stop taking Doxycycline?

If you stop taking Doxycycline suddenly or don't take it at all, Your infection will likely not go away. If you're taking it for malaria prevention, you won't be protected against certain infections.

Can I take Doxycycline for a long time?

The safety of long-term Doxycycline use above 3 months, has not been adequately studied. Because lower doses of Doxycycline and minocycline are frequently used for extended periods to treat acne, it has been presumed that long-term use of Doxycycline at an adult dose of 100 mg/day is safe.

Who should not take Doxycycline?

You should not take Doxycycline if you are allergic to any tetracycline antibiotic.Children younger than 8 years old should use Doxycycline only in cases of severe or life-threatening conditions. Doxycycline can cause permanent yellowing or graying of the teeth in children.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I take too much Doxycycline?

If you take too much you could have dangerous levels of the drug in your body and experience more side effects. If you think you've taken too much of this drug, call your doctor or local poison control center.

Will Doxycycline affect my fertility?

Doxycycline can either help or hurt your fertility,depending on your situation. Check your medicine cabinet and talk to your doctor about any antibiotics or other medicines you take before you try to conceive.

Can Doxycycline affects my heart ?

A previous clinical study found that taking Doxycycline twice a day, for one week after a heart attack improved the health of the patients' hearts.

Can Doxycycline effects my kidney?

Doxycycline has been considered a safe broad-spectrum antibiotic for patients with renal failure. Although Doxycycline possesses many of the metabolic properties of the tetracycline group, toxic blood levels usually do not occur because of the drug's unique extrarenal route of excretion.

Can Doxycycline effects my liver?

Doxycycline is reported to cause acute liver failure, hepatocellular necrosis, and cholestasis.

*** Taking medicines without doctor's advice can cause long-term problems.