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Doxycycline (Monograph)

Brand name: Oracea
Drug class: Skin and Mucous Membrane Agents, Miscellaneous
Chemical name: 4-(Dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,5,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-2-naphthacenecarboxamide monohydrate
Molecular formula: C22H24N2O8•H20
CAS number: 17086-28-1

Medically reviewed by on Jul 22, 2022. Written by ASHP.


Semisynthetic tetracycline antibiotic.

Available as 40-mg capsules (Oracea) containing 2 types of doxycycline beads (i.e., 30 mg as immediate-release beads and 10 mg as delayed-release beads).

Uses for Doxycycline


Treatment of inflammatory lesions (papules and pustules) associated with rosacea (acne rosacea).

Safety and efficacy not established for treatment of the erythematous, telangiectatic, or ocular components of rosacea.

The 40-mg capsules of doxycycline (Oracea) are not indicated for the treatment or prevention of bacterial infections or to reduce the number of or eliminate organisms associated with bacterial disease. (See Selection and Use of Anti-infectives under Cautions).

Doxycycline Dosage and Administration


Oral Administration

Administer orally in the morning, on an empty stomach, at least 1 hour before or 2 hours after a meal.

Give with adequate amounts of fluid to reduce risk of esophageal irritation and ulceration.




40 mg once daily in the morning.

Prescribing Limits



Efficacy of the 40-mg capsules of doxycycline (Oracea) not established beyond 16 weeks and safety not established beyond 9 months of therapy.

Exceeding the dosage of doxycycline recommended for rosacea may increase the incidence of adverse effects (e.g., development of drug-resistant bacteria).

Special Populations

Hepatic Impairment

No specific dosage recommendations at this time.

Renal Impairment

Dosage adjustment not required.

Geriatric Patients

No specific dosage recommendations at this time.

Cautions for Doxycycline


  • Known hypersensitivity to doxycycline or other tetracyclines.



Fetal/Neonatal Morbidity

Animal studies indicate possible fetal toxicity (e.g., retardation of skeletal development) and embryotoxicity.

Use not recommended in pregnant women. Avoid pregnancy during therapy. If pregnancy occurs, immediately discontinue and apprise of potential fetal hazard.

Use not recommended for individuals of either gender who are attempting to conceive a child.

Dental and Bone Effects

Avoid use during tooth development (the last half of pregnancy, infancy, childhood up to 8 years of age); potential for permanent tooth discoloration and enamel hypoplasia.

Tetracyclines form a stable calcium complex in any bone-forming tissue. Reversible decrease in fibula growth rate has occurred in premature infants receiving oral tetracyclines.

Superinfection/Clostridium difficile-associated Colitis

Treatment with anti-infectives may permit overgrowth of clostridia. Consider Clostridium difficile-associated diarrhea and colitis (antibiotic-associated pseudomembranous colitis) if diarrhea develops and manage accordingly.

Some mild cases of C. difficile-associated diarrhea and colitis may respond to discontinuance alone. Manage moderate to severe cases with fluid, electrolyte, protein supplementation, and appropriate anti-infective therapy (e.g., oral metronidazole or vancomycin) as clinically indicated.

Renal Effects

Tetracyclines have antianabolic effects and may increase BUN concentrations. This effect usually is not clinically important in patients with normal renal function; however, high serum tetracycline concentrations may result in azotemia, hyperphosphatemia, and acidosis in patients with impaired renal function. (See Renal Impairment under Cautions.)

Sensitivity Reactions

Photosensitivity Reactions

Possible photosensitivity reaction (e.g., exaggerated sunburn reaction).

Avoid unnecessary exposure to sunlight or artificial UV light (sunlamps, solariums).

General Precautions


Doxycycline may result in overgrowth of nonsusceptible organisms, including fungi. If superinfection occurs, discontinue doxycycline and initiate appropriate therapy.

Tetracyclines may increase the incidence of vaginal candidiasis. Use with caution in patients with a history of or predisposition to candidiasis.

Selection and Use of Anti-infectives

To reduce development of drug-resistant bacteria and maintain effectiveness of other antibacterials, use the 40-mg capsules of doxycycline (Oracea) only for the treatment of rosacea.

Doxycycline 40-mg capsules are not to be used for the treatment or prevention of bacterial infections or to reduce or eliminate organisms associated with bacterial disease. The dosage regimen used for the treatment of rosacea results in doxycycline plasma concentrations that are too low for the treatment of bacterial infections.

Autoimmune Syndromes

Tetracyclines have been associated with autoimmune syndromes (e.g., lupus-like syndrome, autoimmune hepatitis, vasculitis, serum sickness).

If symptoms suggestive of an autoimmune syndrome develop (e.g., fever, rash, arthralgia, malaise), immediately discontinue use of tetracyclines and perform appropriate tests (liver function tests, ANA, CBC) to evaluate the patient.

Tissue Hyperpigmentation

Tetracyclines are known to cause hyperpigmentation in many organs (e.g., nails, bone, skin, eyes, thyroid, visceral tissue, oral cavity, sclerae, and heart valves).

Nervous System Effects

Tetracyclines have been reported to cause bulging fontanels in infants and benign intracranial hypertension (pseudotumor cerebri) in adults. These effects usually resolve when the drug is discontinued.

Laboratory Monitoring

Periodically assess organ system function (including hematopoietic, renal, and hepatic function). Perform appropriate tests for autoimmune syndromes if indicated.

Specific Populations


Category D. (See Fetal/Neonatal Morbidity and Mortality under Cautions.)


Distributed into milk. Discontinue nursing or the drug.

Pediatric Use

Safety and efficacy not established; use not recommended.

Possible permanent tooth discoloration in children <8 years of age. (See Dental and Bone Effects under Cautions.) Do not use in infants or children <8 years of age.

Renal Impairment

Serum half-life of doxycycline is not altered in patients with severe renal impairment; renal impairment does not appear to result in excessive accumulation of doxycycline. (See Renal Effects under Cautions.)

Excessive drug accumulation and possible liver toxicity may occur if usual dosages of some tetracyclines are used in patients with renal impairment. Dosage adjustment of tetracyclines may be necessary in patients with renal impairment; serum tetracycline concentrations should be monitored in patients receiving long-term therapy.

Common Adverse Effects

Nasopharyngitis, hypertension, sinusitis, increased AST, upper respiratory tract infection, headache, diarrhea.

Interactions for Doxycycline

Specific Drugs and Laboratory Tests




Antacids (aluminum-, calcium- or magnesium- containing)

Decreased absorption of doxycycline

Give antacids containing aluminum, calcium, or magnesium 1–2 hours before or after doxycycline

Anticoagulants, oral

Decreased plasma prothrombin activity

Monitor PT carefully; adjust anticoagulant dosage as needed

Anticonvulsants (carbamazepine, barbiturates, phenytoin)

Possible decreased doxycycline half-life

Bismuth subsalicylate

Decreased absorption of doxycycline

If concomitant use cannot be avoided, give doxycycline at least 2-3 hours before bismuth subsalicylate

Hormonal contraceptives

Decreased effectiveness of oral contraceptive

Use of a second form of contraceptive during treatment with doxycycline is advised

Iron-containing preparations

Decreased absorption of doxycycline

Give doxycycline 2 hours before or 3 hours after iron-containing preparations

Methoxyflurane (no longer commercially available in the US)

Fatal renal toxicity


Decreased efficacy of penicillins

Avoid concomitant use

Proton-pump inhibitors

Decreased absorption of doxycycline

Retinoids, oral (e.g., acitretin, isotretinoin)

Additive adverse CNS effect of pseudotumor cerebri (benign intracranial hypertension)

Avoid concomitant use

Urinary catecholamine assay

Possible false elevation secondary to interference with fluorescence test

Doxycycline Pharmacokinetics



Oracea is not bioequivalent to other commercially available doxycycline preparations.


Decreased rate and extent of absorption when administered with a high-fat, high-protein meal including dairy products.

Special Populations

Bioavailability is reported to be reduced at high pH; may be clinically important in patients with gastrectomy, gastric bypass surgery, or those who otherwise are achlorhydric.



Crosses the placenta and is distributed into milk.

Plasma Protein Binding




Major metabolites not identified.

Elimination Route

Excreted in urine (29–55% by 72 hours) and feces as unchanged drug.


21 hours.

Special Populations

No significant difference in serum half-life of patients with normal and severely impaired renal function. Hemodialysis does not alter the serum half-life.





Tight, light-resistant containers at 15–30°C.


  • Semisynthetic tetracycline antibiotic; also has anti-inflammatory and immunomodulatory effects.

  • Mechanism(s) by which doxycycline reduces inflammatory lesions (papules and pustules) in patients with rosacea not known. Effects may result at least in part from the anti-inflammatory and antiangiogenic actions of the drug.

  • The plasma concentrations of doxycycline achieved during therapy with the 40-mg capsules (Oracea) are less than the concentration required to treat bacterial diseases.

  • Causes no long-term effects on bacterial flora of the oral cavity, skin, intestinal tract, or vagina.

Advice to Patients

  • Importance of taking dose in the morning, on an empty stomach (at least 1 hour before or 2 hours after a meal) and drinking sufficient amounts of fluid to reduce the risk of esophageal irritation and ulceration. Importance of not lying down immediately following the dose.

  • Importance of avoiding exposure to direct sunlight or UV light while taking doxycycline. When exposure cannot be avoided, importance of wearing protective clothing. Importance of discontinuing the drug and informing clinician at the first sign of skin erythema.

  • Importance of taking only as prescribed; increasing dosage above 40 mg daily may increase the likelihood that bacteria will develop resistance and will not be treatable by other antibacterial drugs in the future.

  • Importance of women using alternative nonhormonal contraceptive measures because of the potential interaction with hormonal contraceptives.

  • Advise patients that autoimmune syndromes have been observed with doxycycline; importance of discontinuing the drug and informing clinician if arthralgia, fever, rash, or malaise occurs.

  • Advise patients that doxycycline therapy can cause discoloration of skin, scars, teeth, or gums.

  • Importance of providing patient a copy of manufacturer’s patient information.

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal supplements, as well as any concomitant diseases.

  • Importance of women informing their clinician if they are or plan to become pregnant or plan to breast-feed; necessity for clinicians to advise women to avoid pregnancy during therapy, advise pregnant women of risk to the fetus, and advise males to utilize effective contraception during therapy.

  • Importance of informing patients of other important precautionary information. (See Cautions.)


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.



Dosage Forms


Brand Names



Capsules (containing beads)

40 mg (immediate-release 30 mg with delayed-release 10 mg)



AHFS DI Essentials™. © Copyright 2023, Selected Revisions August 1, 2008. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

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