Brand name: Declomycin
Drug class: Tetracyclines
VA class: AM250
CAS number: 64-73-3

Medically reviewed by Drugs.com on Jun 21, 2023. Written by ASHP.

Introduction

Antibacterial; tetracycline antibiotic derived from Streptomyces aureofaciens.¹⁰⁰

Uses for Demeclocycline

Respiratory Tract Infections

Treatment of respiratory tract infections caused by Mycoplasma pneumoniae.¹⁰⁰

Treatment of respiratory tract infections caused by Haemophilus influenzae, Streptococcus pneumoniae, or Klebsiella.¹⁰⁰ Should only be used for treatment of infections caused by these bacteria when in vitro susceptibility tests indicate the organism is susceptible.^{100 a}

Acinetobacter Infections

Treatment of infections caused by Acinetobacter;¹⁰⁰ minocycline may be the preferred tetracycline for use as an alternative to imipenem or meropenem.^e

Acne

Adjunctive treatment of moderate to severe inflammatory acne.¹⁰⁰ Not indicated for treatment of noninflammatory acne.^a

Actinomycosis

Treatment of actinomycosis caused by Actinomyces israelii;¹⁰⁰ oral tetracyclines used as follow-up after initial parenteral treatment with penicillin G.^d

Amebiasis

Adjunct to amebicides for treatment of acute intestinal amebiasis.¹⁰⁰ Tetracyclines generally not recommended for treatment of amebiasis caused by Entamoeba.^d

Anthrax

Alternative to doxycycline for treatment of inhalational anthrax when a parenteral regimen is not available (e.g., when there are supply or logistic problems because large numbers of individuals require treatment in a mass casualty setting).¹⁰⁰ A multiple-drug parenteral regimen (ciprofloxacin or doxycycline and 1 or 2 other anti-infectives predicted to be effective) is preferred for treatment of inhalational anthrax that occurs as the result of exposure to anthrax spores in the context of biologic warfare or bioterrorism.^f

Bartonella Infections

Treatment of infections caused by Bartonella bacilliformis.¹⁰⁰

Brucellosis

Treatment of brucellosis;¹⁰⁰ tetracyclines considered drugs of choice.^{d e} Used in conjunction with other anti-infectives (e.g., streptomycin or gentamicin and/or rifampin),^{100 d e} especially for severe infections or when there are complications (e.g., endocarditis, meningitis, osteomyelitis).^d

Campylobacter Infections

Treatment of infections caused by Campylobacter.¹⁰⁰ Tetracyclines are alternatives, not drugs of choice.^{d e}

Chancroid

Treatment of chancroid caused by Haemophilus ducreyi.¹⁰⁰ Not included in CDC recommendations for treatment of chancroid.¹⁰¹

Chlamydial Infections

Treatment of uncomplicated urethral, endocervical, or rectal infections caused by Chlamydia trachomatis.¹⁰⁰ Doxycycline is the preferred tetracycline for treatment of these infections, including presumptive treatment of chlamydial infections in patients with gonorrhea.¹⁰¹

Treatment of trachoma and inclusion conjunctivitis caused by C. trachomatis.¹⁰⁰ Consider that anti-infectives may not eliminate C. trachomatis in all cases of chronic trachoma.¹⁰⁰

Treatment of lymphogranuloma venereum (genital, inguinal, or anorectal infections) caused by C. trachomatis.¹⁰⁰ Doxycycline is the preferred tetracycline for these infections.^{101 d}

Treatment of psittacosis (ornithosis) caused by C. psittaci.¹⁰⁰ Doxycycline and tetracycline are drugs of choice.^{a d} For initial treatment of severely ill patients, use IV doxycycline.^a

Clostridium Infections

Alternative for treatment of infections caused by Clostridium.¹⁰⁰ Tetracyclines are alternatives to metronidazole or penicillin G for adjunctive treatment of C. tetani infections.^e

Enterobacteriaceae Infections

Treatment of infections caused by susceptible Escherichia coli, Enterobacter aerogenes, Klebsiella, or Shigella.¹⁰⁰ Should only be used for treatment of infections caused by these common gram-negative bacteria when other appropriate anti-infectives are contraindicated or ineffective^a and when in vitro susceptibility tests indicate the organism is susceptible.^{100 a}

Fusobacterium Infections

Alternative to penicillin G for the treatment of infections caused by Fusobacterium fusiforme (Vincent’s infection).¹⁰⁰

Gonorrhea and Associated Infections

Alternative for treatment of uncomplicated gonorrhea (including urethritis) caused by susceptible Neisseria gonorrhoeae.¹⁰⁰ However, tetracyclines are considered inadequate therapy and are not recommended by CDC for treatment of gonorrhea.^{101 a}

Granuloma Inguinale (Donovanosis)

Treatment of granuloma inguinale (donovanosis) caused by Calymmatobacterium granulomatis.¹⁰⁰ Doxycycline is the tetracycline recommended as drug of choice by CDC.¹⁰¹

Listeria Infections

Alternative for treatment of listeriosis caused by Listeria monocytogenes.¹⁰⁰ Not usually considered a drug of choice or alternative for these infections.^{d e}

Nongonococcal Urethritis

Treatment of nongonococcal urethritis (NGU) caused by Ureaplasma urealyticum, C. trachomatis, or Mycoplasma.¹⁰⁰ Doxycycline usually is the tetracycline of choice for NGU.¹⁰¹

Consider that some cases of recurrent urethritis following treatment may be caused by tetracycline-resistant U. urealyticum.¹⁰¹

Plague

Treatment of plague caused by Yersinia pestis.¹⁰⁰ Regimen of choice is streptomycin or gentamicin (with or without doxycycline).^{d e}

Relapsing Fever

Treatment of relapsing fever caused by Borrelia recurrentis.¹⁰⁰ Tetracyclines are drugs of choice.^e

Rickettsial Infections

Treatment of rickettsial infections including Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox, and tick fevers caused by Rickettsiae.¹⁰⁰ Tetracyclines are drugs of choice for treatment of most rickettsial infections; doxycycline usually is the preferred tetracycline.^{a d}

Syndrome of Inappropriate Antidiuretic Hormone Secretion

Treatment of syndrome of inappropriate antidiuretic hormone secretion^{† [off-label]} (SIADH).^a Only limited value in patients with acute water intoxication caused by excess ADH secretion, but may be effective in inhibiting the action of ADH in patients with chronic form of the disease.^a

Also has been used to treat hyponatremia and water retention^{† [off-label]} in patients with congestive heart failure or cirrhosis, but a high incidence of renal failure has been reported and the drug probably should not be used in these patients.^a

Syphilis

Alternative to penicillin G for treatment of primary, secondary, latent, or tertiary syphilis (not neurosyphilis) in nonpregnant adults and adolescents hypersensitive to penicillins.¹⁰⁰ Doxycycline and tetracycline are the preferred tetracyclines in patients hypersensitive to penicillins.¹⁰¹ Use tetracyclines only if compliance and follow-up can be ensured since efficacy not well documented.¹⁰¹

Tularemia

Treatment of tularemia caused by Francisella tularensis.¹⁰⁰ Tetracyclines considered alternatives to streptomycin (or gentamicin);^{d e g} risk of relapse and primary treatment failure may be higher than with aminoglycosides.^g

Vibrio Infections

Treatment of cholera caused by Vibrio cholerae.¹⁰⁰ Doxycycline and tetracycline are drugs of choice; used as an adjunct to fluid and electrolyte replacement in moderate to severe disease.^{d e}

Yaws

Alternative to penicillin G for treatment of yaws caused by Treponema pertenue.¹⁰⁰

Related/similar drugs

amoxicillin, doxycycline, cephalexin, ciprofloxacin, azithromycin, metronidazole, conivaptan

Demeclocycline Dosage and Administration

Administration

Oral Administration

Administer orally 1 hour before or 2 hours after meals and/or milk.¹⁰⁰

Administer with adequate amounts of fluid to reduce the risk of esophageal irritation and ulceration.¹⁰⁰

Dosage

Pediatric Patients

General Pediatric Dosage

Oral

Children >8 years of age: 7–13 mg/kg daily given in 2–4 divided doses.^c

Adults

General Adult Dosage

Oral

150 mg 4 times daily or 300 mg 2 times daily.^c

Gonorrhea and Associated Infections

Oral

600 mg initially followed by 300 mg every 12 hours for 4 days for a total of 3 g.¹⁰⁰

No longer recommended for gonorrhea by CDC or other experts.¹⁰¹

Syndrome of Inappropriate Antidiuretic Hormone Secretion† [off-label]

Oral

600 mg to 1.2 g daily in 3 or 4 divided doses.^b Diuresis usually occurs within 5 days after initiation of therapy and reverses within 2–6 days after drug discontinued.^b

Prescribing Limits

Pediatric Patients

Maximum 600 mg daily.^c

Special Populations

Hepatic Impairment

Adjust dosage by decreasing doses or increasing dosing interval.¹⁰⁰

Use with caution.¹⁰⁰

Renal Impairment

Adjust dosage by decreasing doses or increasing dosing interval.¹⁰⁰

Use with caution.¹⁰⁰

Cautions for Demeclocycline

Contraindications

• Known hypersensitivity to demeclocycline, other tetracyclines, or any ingredient in the formulation.¹⁰⁰

Warnings/Precautions

Warnings

Adverse Dental and Bone Effects

Use during tooth development (e.g., pregnancy, children <8 years of age) may cause permanent yellow-gray to brown discoloration of teeth and enamel hypoplasia¹⁰⁰ Effects are most common following long-term use, but may occur following repeated short-term use.¹⁰⁰

Tetracyclines form a stable calcium complex in any bone-forming tissue.¹⁰⁰ Reversible decrease in fibula growth rate has occurred in prematures receiving tetracycline.¹⁰⁰

Use not recommended in children <8 years of age unless other appropriate drugs are ineffective or are contraindicated or unless the benefits in certain indications (e.g., anthrax) outweigh the risks.¹⁰⁰ (See Pediatric Use under Cautions.)

Fetal/Neonatal Morbidity

Animal studies indicate possible fetal toxicity (e.g., retardation of skeletal development) and embryotoxicity.¹⁰⁰ If used during pregnancy or if patient becomes pregnant while receiving demeclocycline, patient should be apprised of the potential hazard to the fetus.¹⁰⁰ (See Pregnancy under Cautions.)

Nervous System Effects

Possibility of adverse CNS effects (light-headedness, dizziness, vertigo) that may impair ability to drive vehicles or operate hazardous machinery.¹⁰⁰

Benign intracranial hypertension (pseudotumor cerebri) in adults reported with tetracyclines; usually manifested as headache and blurred vision.¹⁰⁰ Bulging fontanels reported in infants.¹⁰⁰ Effects usually resolve when drug discontinued, but possibility for permanent sequelae exists.¹⁰⁰

Renal Effects

Tetracyclines have antianabolic effects and may increase BUN.¹⁰⁰

In patients with impaired renal function, high serum demeclocycline concentrations may result in azotemia, hyperphosphatemia, and acidosis.¹⁰⁰ Excessive drug accumulation and possible liver toxicity may occur if usual dosage is used patients with renal impairment.¹⁰⁰ (See Renal Impairment under Dosage and Administration.)

Diabetes Insipidus Syndrome

Diabetes insipidus syndrome (polyuria, polydipsia and weakness) reported with long-term demeclocycline therapy.¹⁰⁰ Syndrome is nephrogenic, dose-dependent, and reversible when drug discontinued.¹⁰⁰

Laboratory Monitoring

Periodically assess organ system function, including renal, hepatic and hematopoietic, during long-term therapy.¹⁰⁰

Sensitivity Reactions

Photosensitivity Reactions

Photosensitivity, manifested by an exaggerated sunburn reaction, reported with tetracyclines.¹⁰⁰

Photosensitivity reactions may develop within a few minutes to several hours after sun exposure and usually persist 1–2 days after discontinuance of the drug.^a Most reactions result from accumulation of tetracyclines in skin and are phototoxic in nature; photoallergic reactions may also occur.^a

Discontinue drug at first evidence of skin erythema.¹⁰⁰

General Precautions

Superinfection

Possible emergence and overgrowth of nonsusceptible bacteria or fungi.¹⁰⁰ Discontinue drug and institute appropriate therapy if superinfection occurs.¹⁰⁰

Selection and Use of Anti-infectives

Because many strains of Acinetobacter, Bacteroides, Enterobacter, E. coli, Klebsiella, Shigella, S. pyogenes (group A β-hemolytic streptococci), S. pneumoniae, enterococci, and α-hemolytic streptococci are resistant to tetracyclines (including demeclocycline), in vitro susceptibility tests should be performed if the drug is used for treatment of infections caused by these bacteria.¹⁰⁰

Incision and drainage or other surgical procedures should be performed in conjunction with demeclocycline therapy when indicated.¹⁰⁰

Specific Populations

Pregnancy

Category D.¹⁰⁰ (See Fetal/Neonatal Morbidity under Cautions.)

Lactation

Distributed into milk;¹⁰⁰ discontinue nursing or the drug.¹⁰⁰

AAP states maternal use of tetracyclines usually is compatible with breast-feeding since absorption of the drugs by nursing infants is negligible.^d

Pediatric Use

Should not be used in children <8 years of age unless benefits outweigh the risks.¹⁰⁰ (See Adverse Dental and Bone Effects under Cautions.)

Hepatic Impairment

Use with caution.¹⁰⁰ Reduce dosage.¹⁰⁰

Renal Impairment

Use with caution.¹⁰⁰ Reduce dosage.¹⁰⁰

Because usual dosage of doxycycline can be used in patients with impaired renal function, it may preferred when a tetracycline is indicated in a patient with impaired renal function.^b

Common Adverse Effects

GI effects (anorexia, nausea, vomiting, diarrhea); maculopapular and erythematous rash; dose-related BUN increase; hypersensitivity reactions.¹⁰⁰

Drug Interactions

Specific Drugs

Demeclocycline Pharmacokinetics

Absorption

Bioavailability

Approximately 60–80% of a dose absorbed from the GI tract in fasting adults.^b Peak serum concentrations attained within 2–4 hours.^{b c}

Food

Food and/or milk decrease GI absorption by ≥50%.^{b c}

Distribution

Extent

Well distributed into body tissues and fluids.^c

Plasma Protein Binding

36–91%.^{a c}

Elimination

Metabolism

Does not appear to be metabolized.^a

Elimination Route

Excreted into the GI tract via bile and by nonbiliary routes.^a Excreted in urine by glomerular filtration.^{a c}

44% of a 150-mg oral dose excreted in urine and 13–46% excreted in feces as unchanged drug.^{b c}

Half-life

Adults with normal renal function: 10–17 hours.^{b c}

Special Populations

Patients with severe renal impairment: half-life 42–68 hours.^b

Stability

Storage

Oral

Tablets

20–25°C.¹⁰⁰

Actions and Spectrum

• Usually bacteriostatic,^{100 a} but may be bactericidal in high concentrations or against highly susceptible organisms.^a

• Inhibits protein synthesis¹⁰⁰ in susceptible organisms by reversibly binding to 30S and 50S ribosomal subunits.^a

• The complete mechanisms by which tetracyclines reduce acne lesions have not been fully elucidated.^a The effects appear to result in part from the antibacterial activity of the drugs, but other mechanisms also are involved.^a

• Spectrum of activity includes many gram-positive and -negative bacteria and various other organisms (e.g., Rickettsia, Chlamydia, Mycoplasma, spirochetes).^{a c} Inactive against fungi and viruses.^a

• Gram-positive aerobes and anaerobes: active against Actinomyces israelii, Bacillus anthracis, Clostridium, Propionibacterium acnes, and some staphylococci and streptococci.^{a c} Many strains of S. pyogenes and Enterococci are resistant.^a

• Gram-negative aerobes and anaerobes: active against Bartonella bacilliformis, Brucella, Calymmatobacterium granulomatis, Francisella tularensis, Haemophilus ducreyi, H. influenzae, Neisseria gonorrhoeae, Vibrio cholerae, and Y. pestis.¹⁰⁰ Many strains of Acinetobacter, E. aerogenes, E. coli, Klebsiella, and Shigella and nearly all strains of Proteus and Pseudomonas are resistant.^{a c}

• Other organisms: active against Rickettsia, Coxiella burnetii, Chlamydia psittaci, C. trachomatis, Mycoplasma hominis, M. pneumoniae, Ureoplasma urealyticum, B. recurrentis, Leptospira, Treponema pallidum, and T. pertenue.^{a c}

• Complete cross-resistance usually occurs between demeclocycline and other tetracyclines (doxycycline, minocycline, oxytetracycline, tetracycline).^{a c}

Advice to Patients

• Importance of drinking sufficient quantities of fluids when taking tablets to reduce the risk of esophageal irritation and ulceration.¹⁰⁰

• Advise patients that absorption of demeclocycline may be reduced when taken with foods, especially those containing calcium, and that tablets should be taken at least 1 hour before or 2 hours after meals and/or milk.¹⁰⁰

• Advise patients that adverse CNS effects (light-headedness, dizziness, vertigo) may occur and caution should be used when driving vehicles or operating hazardous machinery.¹⁰⁰

• Advise patients to avoid excessive sunlight or artificial UV light and to discontinue the drug at the first sign of skin erythema;¹⁰⁰ consider use of sunscreen or sunblock.^a

• Advise patients that demeclocycline may decrease effectiveness of oral contraceptives and that alternative nonhormonal contraceptive measures should be used.¹⁰⁰

• Advise patients that unused supplies of demeclocycline should be discarded by the expiration date.¹⁰⁰

• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.¹⁰⁰ (See Fetal/Neonatal Morbidity under Cautions.)

• Importance of informing clinicians of existing or contemplated therapy, including prescription and OTC drugs.¹⁰⁰

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

Preparations

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.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Medical Disclaimer