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Demeclocycline

Pronunciation

Pronunciation

(dem e kloe SYE kleen)

Index Terms

  • Declomycin
  • Demeclocycline Hydrochloride
  • Demethylchlortetracycline

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral, as hydrochloride:

Generic: 150 mg, 300 mg

Pharmacologic Category

  • Antibiotic, Tetracycline Derivative

Pharmacology

Inhibits protein synthesis by binding with the 30S and possibly the 50S ribosomal subunit(s) of susceptible bacteria; may also cause alterations in the cytoplasmic membrane; inhibits the action of ADH in patients with chronic SIADH

Absorption

66%; extent of absorption is reduced by food and by certain antacids and dairy products containing aluminum, calcium, magnesium, or iron

Distribution

1.7 L/kg

Metabolism

None

Excretion

Urine (44% as unchanged drug); feces (13% to 46% as unchanged drug)

Onset of Action

SIADH: 2-5 days

Time to Peak

Serum: ~4 hours

Half-Life Elimination

10-16 hours

Protein Binding

40% to 90%

Use: Labeled Indications

Treatment of susceptible bacterial infections (eg, acne, urinary tract infections, respiratory infections) caused by both gram-negative and gram-positive organisms

Note: Use of demeclocycline as an antibacterial agent is uncommon; alternative tetracycline agents (eg, doxycycline, minocycline, tetracycline) are generally preferred.

Use: Unlabeled

Treatment of chronic syndrome of inappropriate secretion of antidiuretic hormone (SIADH)

Contraindications

Hypersensitivity to demeclocycline, tetracyclines, or any component of the formulation

Dosage

Susceptible infections: Manufacturer’s labeling:

Children >8 years: Oral: 7 to 13 mg/kg/day (maximum: 600 mg/day) divided every 6 to 12 hours

Adults: Oral: 150 mg 4 times/day or 300 mg twice daily

SIADH (off-label use): Adults: Oral: 600 to 1,200 mg/day (Goh, 2004; Gross, 2008, Verbalis, 2013). Note: Limited high quality evidence exists to define the clinical role, if any, of demeclocycline in this condition. European clinical practice guidelines recommend against the use of demeclocycline for the management of hyponatremia in patients with SIADH (Spasovski, 2014).

Dosage adjustment in renal impairment: Use with caution; dosage adjustment and/or increase in time interval between doses recommended in manufacturer’s labeling; no specific adjustment recommendations provided.

Dosage adjustment in hepatic impairment: Use with caution; dosage adjustment and/or increase in time interval between doses recommended in manufacturer’s labeling; no specific adjustment recommendations provided.

Administration

Administer 1 hour before or 2 hours after food or milk. Administer with adequate amounts of fluid to decrease the risk of esophageal irritation and ulceration.

Dietary Considerations

Due to potential for decreased absorption, administer 1 hour before or 2 hours after food or milk.

Storage

Store at controlled room temperature at 20°C to 25°C (68°F to 77°F).

Drug Interactions

Antacids: May decrease the absorption of Tetracycline Derivatives. Consider therapy modification

BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Avoid combination

BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Monitor therapy

Bile Acid Sequestrants: May decrease the absorption of Tetracycline Derivatives. Consider therapy modification

Bismuth Subcitrate: May decrease the serum concentration of Tetracycline Derivatives. Management: Avoid administration of oral tetracyclines within 30 minutes of bismuth subcitrate administration. This is of questionable significance for at least some regimens intended to treat H. pylori infections. Consider therapy modification

Bismuth Subsalicylate: May decrease the serum concentration of Tetracycline Derivatives. Management: Consider dosing tetracyclines 2 hours before or 6 hours after bismuth. The need to separate doses during Helicobacter pylori eradication regimens is questionable. Consider therapy modification

Calcium Salts: May decrease the serum concentration of Tetracycline Derivatives. Management: If coadministration of oral calcium with oral tetracyclines can not be avoided, consider separating administration of each agent by several hours. Consider therapy modification

Desmopressin: Demeclocycline may diminish the therapeutic effect of Desmopressin. Monitor therapy

Iron Salts: Tetracycline Derivatives may decrease the absorption of Iron Salts. Iron Salts may decrease the serum concentration of Tetracycline Derivatives. Exceptions: Ferric Carboxymaltose; Ferric Gluconate; Ferric Pyrophosphate Citrate; Ferumoxytol; Iron Dextran Complex; Iron Sucrose. Consider therapy modification

Lanthanum: May decrease the serum concentration of Tetracycline Derivatives. Management: Administer oral tetracycline antibiotics at least two hours before or after lanthanum. Consider therapy modification

Magnesium Dimecrotate: May interact via an unknown mechanism with Tetracycline Derivatives. Monitor therapy

Magnesium Salts: May decrease the absorption of Tetracycline Derivatives. Only applicable to oral preparations of each agent. Consider therapy modification

Mecamylamine: Tetracycline Derivatives may enhance the neuromuscular-blocking effect of Mecamylamine. Avoid combination

Mipomersen: Tetracycline Derivatives may enhance the hepatotoxic effect of Mipomersen. Monitor therapy

Multivitamins/Minerals (with ADEK, Folate, Iron): May decrease the serum concentration of Tetracycline Derivatives. Management: If coadministration of a polyvalent cation-containing multivitamin with oral tetracyclines can not be avoided, separate administration of each agent by several hours. Consider therapy modification

Multivitamins/Minerals (with AE, No Iron): May decrease the serum concentration of Tetracycline Derivatives. Management: If coadministration of a polyvalent cation-containing multivitamin with oral tetracyclines can not be avoided, separate administration of each agent by several hours. Consider therapy modification

Neuromuscular-Blocking Agents: Tetracycline Derivatives may enhance the neuromuscular-blocking effect of Neuromuscular-Blocking Agents. Monitor therapy

Penicillins: Tetracycline Derivatives may diminish the therapeutic effect of Penicillins. Consider therapy modification

Porfimer: Photosensitizing Agents may enhance the photosensitizing effect of Porfimer. Monitor therapy

Quinapril: May decrease the serum concentration of Tetracycline Derivatives. Management: Separate doses of quinapril and oral tetracycline derivatives by at least 2 hours in order to reduce the risk of interaction. Monitor for reduced efficacy of the tetracycline if these products are used concomitantly. Consider therapy modification

Retinoic Acid Derivatives: Tetracycline Derivatives may enhance the adverse/toxic effect of Retinoic Acid Derivatives. The development of pseudotumor cerebri is of particular concern. Exceptions: Adapalene; Bexarotene (Topical); Tretinoin (Topical). Avoid combination

Sodium Picosulfate: Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Consider therapy modification

Strontium Ranelate: May decrease the serum concentration of Tetracycline Derivatives. Management: In order to minimize any potential impact of strontium ranelate on tetracycline antibiotic concentrations, it is recommended that strontium ranelate treatment be interrupted during tetracycline therapy. Avoid combination

Sucralfate: May decrease the absorption of Tetracycline Derivatives. Management: Administer the tetracycline derivative at least 2 hours prior to sucralfate in order to minimize the impact of this interaction. Consider therapy modification

Sucroferric Oxyhydroxide: May decrease the serum concentration of Tetracycline Derivatives. Management: Administer oral/enteral doxycycline at least 1 h before sucroferric oxyhydroxide. Specific dose separation guidelines for other tetracyclines are not presently available. No interaction is anticipated with parenteral administration of tetracyclines. Consider therapy modification

Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents. Consider therapy modification

Verteporfin: Photosensitizing Agents may enhance the photosensitizing effect of Verteporfin. Monitor therapy

Vitamin K Antagonists (eg, warfarin): Tetracycline Derivatives may enhance the anticoagulant effect of Vitamin K Antagonists. Monitor therapy

Zinc Salts: May decrease the absorption of Tetracycline Derivatives. Only a concern when both products are administered orally. Management: Consider doxycycline as a noninteracting tetracycline derivative. Separate dose administration of oral tetracycline derivative and oral zinc salts by at least 2 hours to minimize interaction. Exceptions: Zinc Chloride. Consider therapy modification

Adverse Reactions

Frequency not defined.

Cardiovascular: Pericarditis

Central nervous system: Bulging fontanels (infants), dizziness, headache, pseudotumor cerebri (adults)

Dermatologic: Angioedema, anogenital inflammatory lesions (with monilial overgrowth), erythema multiforme, erythematous rash, exfoliative dermatitis (rare), maculopapular rash, photosensitivity, pigmentation of skin, Stevens-Johnson syndrome (rare), urticaria

Endocrine & metabolic: Microscopic discoloration of thyroid gland (brown/black), nephrogenic diabetes insipidus, thyroid dysfunction (rare)

Gastrointestinal: Anorexia, diarrhea, dysphagia, enterocolitis, esophageal ulcerations, glossitis, nausea, pancreatitis, vomiting

Genitourinary: Balanitis

Hematologic: Eosinophilia, neutropenia, hemolytic anemia, thrombocytopenia

Hepatic: Hepatitis (rare), hepatotoxicity (rare), liver enzymes increased, liver failure (rare)

Neuromuscular & skeletal: Myasthenic syndrome, polyarthralgia, tooth discoloration (children <8 years, rarely in adults)

Ocular: Visual disturbances

Otic: Tinnitus

Renal: Acute renal failure, BUN increased

Respiratory: Pulmonary infiltrates

Miscellaneous: Anaphylaxis, anaphylactoid purpura, fixed drug eruptions (rare), lupus-like syndrome, superinfection, systemic lupus erythematosus exacerbation

Warnings/Precautions

Concerns related to adverse effects:

• Diabetes insipidus syndrome: Dose-dependent nephrogenic diabetes insipidus is common with use; however, this adverse event of demeclocycline has been used as a therapeutic advantage in the off-label use of hyponatremia associated with SIADH.

• Increased BUN: May be associated with increases in BUN secondary to antianabolic effects; use caution in patients with renal impairment.

• Photosensitivity: May cause photosensitivity; discontinue if skin erythema occurs. Use skin protection and avoid prolonged exposure to sunlight; do not use tanning equipment.

• Pseudotumor cerebri: Has been (rarely) reported with tetracycline use; usually resolves with discontinuation.

• Superinfection: Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months postantibiotic treatment.

Disease-related concerns:

• Hepatic impairment: Use with caution in patients with hepatic impairment; dose adjustment and/or adjustment to interval frequency recommended. Hepatotoxicity and hepatic failure have been reported rarely with use.

• Renal impairment: Use with caution in patients with renal impairment; dosage adjustment recommended. Nephrotoxicity has also been reported with use, particularly in the setting of cirrhosis.

Concurrent drug therapy issues:

• Methoxyflurane: Concurrent use of tetracyclines and methoxyflurane (not available in the U.S.) is not recommended; fatal renal toxicity has been reported with concurrent use.

Special populations:

• Pediatric: May cause tissue hyperpigmentation, enamel hypoplasia, or permanent tooth discoloration; use of tetracyclines should be avoided during tooth development (children <8 years of age) unless other drugs are not likely to be effective or are contraindicated.

• Pregnancy: Do not use during pregnancy. In addition to affecting tooth development, tetracycline use has been associated with retardation of skeletal development and reduced bone growth.

Monitoring Parameters

CBC, renal and hepatic function

Pregnancy Risk Factor

D

Pregnancy Considerations

Tetracyclines, including demeclocycline, cross the placenta and accumulate in developing teeth and long tubular bones. Tetracyclines may discolor fetal teeth following maternal use during pregnancy; the specific teeth involved and the portion of the tooth affected depends on the timing and duration of exposure relative to tooth calcification. As a class, tetracyclines are generally considered second-line antibiotics in pregnant women and their use should be avoided (Gibbons, 1960; Mylonas, 2011).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience diarrhea, dizziness, nausea, or lack of appetite. Have patient report immediately to prescriber vision changes, urinary retention, oliguria, severe headache, ecchymosis, hemorrhaging, considerable asthenia, or signs of pseudomembranous colitis (rare) (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.

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