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Demeclocycline

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Demeclocycline
Clinical data
Routes of
administration
Oral
ATC code
Legal status
Legal status
  • In general: ℞ (Prescription only)
Pharmacokinetic data
Bioavailability60–80%
Protein binding41–50%
MetabolismHepatic
Elimination half-life10–17 hours
ExcretionRenal
Identifiers
  • (2E,4S,4aS,5aS,6S,12aS)-2-[amino(hydroxy)methylidene]-7-chloro-4-(dimethylamino)-6,10,11,12a-tetrahydroxy-1,2,3,4,4a,5,5a,6,12,12a-decahydrotetracene-1,3,12-trione
CAS Number
PubChem CID
DrugBank
CompTox Dashboard (EPA)
ECHA InfoCard100.004.396 Edit this at Wikidata
Chemical and physical data
FormulaC21H21ClN2O8
Molar mass464.853 g/mol g·mol−1

Demeclocycline (marketed as Declomycin, Declostatin and Ledermycin) is a tetracycline antibiotic.

It is derived from a strain of Streptomyces aureofaciens.[1]

Uses

In infections

It is officially indicated for the treatment of various types of bacterial infections.[2]

Its use as an antibiotic is particularly in Lyme disease, acne and bronchitis.[citation needed]

Resistance is gradually becoming more common, and demeclocycline is now rarely used for infections.

In SIADH

It is widely used (though off-label in many countries) in the treatment of hyponatremia (low blood sodium concentration) due to the syndrome of inappropriate antidiuretic hormone (SIADH) when fluid restriction alone has been ineffective.[3]

The use in SIADH actually relies on a side effect; demeclocycline induces nephrogenic diabetes insipidus (dehydration due to the inability to concentrate urine).[3] The use of demeclocycline in SIADH was first reported in 1975,[4] and, in 1978, a larger study found it to be more effective and better tolerated than lithium carbonate, the only available treatment at the time.[5] Demeclocycline has since been the drug of choice for treating SIADH, although it may be superseded as vasopressin receptor antagonists such as tolvaptan become available.[5]

Contraindications

As other tetracyclines, demeclocycline is contraindicated in children and pregnant or nursing women. All members of this class interfere with bone development and may discolour teeth.[6]

Side effects and interactions

These are similar to those of other tetracyclines. Skin reactions with sunlight have been reported.[5] Demeclocycline is unique in that it is the only tetracycline known to cause nephrogenic diabetes insipidus.

Tetracyclines bind to cations such as calcium, iron (when given orally), and magnesium, rendering them insoluble and inabsorbable for the GI tract. Demeclocycline should not be taken with food (particularly milk and other dairy products) or antacids.[6]

Mechanism of action

As with related tetracycline antibiotics, demeclocycline acts by binding to the 30S- and 50S-RNA, which impairs protein synthesis by bacteria. It is therefore bacteriostatic (it impairs bacterial growth but does not kill bacteria directly).

It is not completely understood why demeclocycline impairs the action of antidiuretic hormone, but it is thought that it blocks the binding of the hormone to its receptor.[7]

References

  1. ^ "demeclocycline" at Dorland's Medical Dictionary
  2. ^ "DailyMed: About DailyMed". Retrieved 2008-12-20.
  3. ^ a b Goh KP (2004). "Management of hyponatremia". American Family Physician. 69 (10): 2387–94. PMID 15168958. {{cite journal}}: Unknown parameter |month= ignored (help)
  4. ^ Cherrill DA, Stote RM, Birge JR, Singer I (1975). "Demeclocycline treatment in the syndrome of inappropriate antidiuretic hormone secretion". Annals of Internal Medicine. 83 (5): 654–6. PMID 173218. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  5. ^ a b c Tolstoi LG (2002). "A brief review of drug-induced syndrome of inappropriate secretion of antidiuretic hormone". Medscape Pharmacotherapy. 4 (1). Retrieved on October 27, 2008.
  6. ^ a b Lexi-Comp (August 2008). "Demeclocycline". The Merck Manual Professional. Retrieved on October 27, 2008.
  7. ^ De Troyer A, Demanet JC (1975). "Correction of antidiuresis by demeclocycline". N Engl J Med. 293 (18): 915–8. PMID 170519.