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Pronunciation:

(dem e kloe SYE kleen)

U.S. Brand Names:

Declomycin®

Synonyms:

Demeclocycline Hydrochloride; Demethylchlortetracycline

Generic Available:

Yes

Canadian Brand Names:

Declomycin®

Use:

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

Use - Unlabeled/Investigational:

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

Pregnancy Risk Factor:

Pregnancy Implications:

Tetracyclines cross the placenta and enter fetal circulation; may cause permanent discoloration of teeth if used during the last half of pregnancy. Related antibiotics have been associated with mutagenesis, embryotoxicity, and oncogenic activity in animals.

Lactation:

Enters breast milk/not recommended (AAP rates tetracycline "compatible")

Contraindications:

Hypersensitivity to demeclocycline, tetracyclines, or any component of the formulation; children <8 years of age; concomitant use with methoxyflurane; pregnancy

Warnings/Precautions:

Photosensitivity reactions occur frequently with this drug, avoid prolonged exposure to sunlight, do not use tanning equipment. Use of tetracyclines during tooth development may cause permanent discoloration of the teeth and enamel, hypoplasia and retardation of skeletal development and bone growth with risk being the greatest for children <4 years and those receiving high doses; use caution in patients with renal or hepatic impairment (eg, elderly); dosage modification required in patients with renal impairment; may act as an anti-anabolic agent and increase BUN; pseudotumor cerebri has been reported with tetracycline use (usually resolves with discontinuation); outdated drug can cause nephropathy; superinfection possible

Adverse Reactions:

Frequency not defined.

Cardiovascular: Pericarditis

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

Dermatologic: Angioneurotic edema, erythema multiforme, erythematous rash, maculopapular rash, photosensitivity, pigmentation of skin, Stevens-Johnson syndrome (rare), urticaria

Endocrine & metabolic: Discoloration of thyroid gland (brown/black), nephrogenic diabetes insipidus

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

Respiratory: Pulmonary infiltrates

Miscellaneous: Anaphylaxis, anaphylactoid purpura, lupus-like syndrome, systemic lupus erythematosus exacerbation

Overdosage/Toxicology:

Treatment is supportive.

Drug Interactions:

Antacids: Preparations containing calcium, magnesium, aluminum bismuth, or sodium bicarbonate may decrease absorption of tetracyclines

Bile acid sequestrants: May decrease tetracycline absorption.

Iron preparations: May decrease absorption of tetracyclines.

Methoxyflurane: Methoxyflurane anesthesia (when concurrent with tetracycline) may cause fatal nephrotoxicity; concurrent use is contraindicated.

Methotrexate: Clearance of methotrexate (high-dose therapy) may be decreased by tetracyclines.

Oral contraceptives: Anecdotal reports suggesting decreased contraceptive efficacy with tetracyclines have been refuted by more rigorous scientific and clinical data.

Penicillins: May decrease therapeutic effect of tetracyclines.

Quinapril: Magnesium-containing formulation of quinapril may decrease tetracycline absorption.

Retinoic acid derivatives: May increase adverse and toxic effects of tetracyclines, especially pseudotumor cerebri.

Warfarin: Concomitant use with tetracyclines may result in increased anticoagulation.

Zinc preparations: May decrease absorption of tetracyclines.

Ethanol/Nutrition/Herb Interactions:

Food: Demeclocycline serum levels may be decreased if taken with food.

Herb/Nutraceutical: Avoid dong quai, St John's wort (may also cause photosensitization).

Stability:

Tetracyclines form toxic products when outdated or when exposed to light, heat, or humidity (Fanconi-like syndrome)

Mechanism of Action:

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

Pharmacodynamics/Kinetics:

Onset of action: SIADH: Several days

Absorption: ~50% to 80%; reduced by food and dairy products

Protein binding: 41% to 50%

Metabolism: Hepatic (small amounts) to inactive metabolites; undergoes enterohepatic recirculation

Half-life elimination: 10-17 hours

Time to peak, serum: 3-6 hours

Excretion: Urine (42% to 50% as unchanged drug)

Dosage:

Oral:

Children 8 years: 8-12 mg/kg/day divided every 6-12 hours

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

SIADH (unlabeled use): 900-1200 mg/day or 13-15 mg/kg/day divided every 6-8 hours initially, then decrease to 600-900 mg/day

Dosing adjustment/comments in renal/hepatic impairment: Should be avoided in patients with renal/hepatic dysfunction

Administration:

Administer 1 hour before or 2 hours after food or milk with plenty of fluid

Monitoring Parameters:

CBC, renal and hepatic function

Test Interactions:

May interfere with tests for urinary glucose (false-negative urine glucose using Clinistix®, Tes-Tape®)

Dietary Considerations:

Should be taken 1 hour before or 2 hours after food or milk with plenty of fluid.

Patient Education:

Inform prescriber of all prescriptions, OTC medications, or herbal products you are taking, and any allergies you have. Do not take any new medication during therapy unless approved by prescriber. Take on an empty stomach (1 hour before or 2 hours after meals with plenty of fluid). Take at regularly scheduled intervals around-the-clock. Avoid antacids, iron, dairy products, and other medications within 2 hours of taking demeclocycline. May cause photosensitivity (use sunscreen, wear protective clothing and eyewear, and avoid direct sunlight); dizziness or lightheadedness (use caution when driving or engaging in tasks that require alertness until response to drug is known); nausea or vomiting (frequent, small meals, frequent mouth care, sucking lozenges, or chewing gum may help); or diarrhea (buttermilk, yogurt, or boiled milk may help). Report rash or intense itching, yellowing of skin or eyes, change in color of urine or stools, fever or chills, dark urine or pale stools, vaginal itching or discharge, foul-smelling stools, excessive thirst or urination, acute headache, unresolved diarrhea, or respiratory difficulty. Pregnancy/breast-feeding precautions: Inform prescriber if you are pregnant. Do not get pregnant while taking this medication. Consult prescriber for appropriate contraceptives. Breast-feeding is not recommended.

Dental Health: Effects on Dental Treatment:

Tetracyclines are not recommended for use during pregnancy or in children 8 years of age since they have been reported to cause enamel hypoplasia and permanent teeth discoloration. Tetracyclines should only be used in these patients if other agents are contraindicated or alternative antimicrobials will not eradicate the organism. Long-term use associated with oral candidiasis.

Dental Health: Vasoconstrictor/Local Anesthetic Precautions:

No information available to require special precautions

Mental Health: Effects on Psychiatric Treatment:

Barbiturates and carbamazepine may decrease the effects of demeclocycline

Dosage Forms:

Tablet, as hydrochloride: 150 mg, 300 mg

International Brand Names:

Declomycin® (CA); Ledermycin® (AU, GB, IN, LU, NL, NZ); Lédermycine® (FR)

References

Abdi EA and Bishop S, "The Syndrome of Inappropriate Antidiuretic Hormone Secretion With Carcinoma of the Tongue,"Med Pediatr Oncol, 1988, 16(3):210-5.

"American Academy of Pediatrics Committee on Drugs. The Transfer of Drugs and Other Chemicals Into Human Milk,"Pediatrics, 2001, 108(3):776-89.

Smilack JD, Wilson WR, and Cockerill FR 3d, "Tetracyclines, Chloramphenicol, Erythromycin, Clindamycin, and Metronidazole,"Mayo Clin Proc, 1991, 66(12):1270-80.

Troyer AD, "Demeclocycline. Treatment for Syndrome of Inappropriate Antidiuretic Hormone Secretion,"JAMA, 1977, 237(25):2723-6.

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