Demeclocycline ( INN,

BAN Ban, or BAN, may refer to: Law * Ban (law), a decree that prohibits something, sometimes a form of censorship, being denied from entering or using the place/item ** Imperial ban (''Reichsacht''), a form of outlawry in the medieval Holy Roman ...

, USAN, brand name Declomycin) is a tetracycline antibiotic which was derived from a mutant strain of ''

Streptomyces aureofaciens ''Kitasatospora aureofaciens'' is a species of ''Kitasatospora'', and the source of many tetracycline antibiotics. The organism was first isolated at Sanborn Field on the University of Missouri campus in Columbia, Missouri, US; the site became a ...

''.

Uses

Demeclocycline is officially indicated for the treatment of various types of

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...

s. It is used as an antibiotic in the treatment of

Lyme disease Lyme disease, also known as Lyme borreliosis, is a vector-borne disease caused by the '' Borrelia'' bacterium, which is spread by ticks in the genus '' Ixodes''. The most common sign of infection is an expanding red rash, known as erythema ...

acne Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...

, and bronchitis. Resistance, though, is gradually becoming more common, and demeclocycline is now rarely used for treatment of infections. Retrieved on October 27, 2008. It is widely used (though

off-label Off-label use is the use of pharmaceutical drugs for an unapproved indication or in an unapproved age group, dosage, or route of administration. Both prescription drugs and over-the-counter drugs (OTCs) can be used in off-label ways, although ...

in many countries including the United States) in the treatment of hyponatremia (low blood

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

concentration) due to the

syndrome of inappropriate antidiuretic hormone Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is characterized by excessive unsuppressible release of antidiuretic hormone (ADH) either from the posterior pituitary gland, or an abnormal non-pituitary source. Unsuppressed ADH ca ...

(SIADH) when fluid restriction alone has been ineffective. Physiologically, this works by reducing the responsiveness of the collecting tubule cells to ADH. The use in SIADH actually relies on a side effect; demeclocycline induces nephrogenic diabetes insipidus (dehydration due to the inability to concentrate urine). The use of demeclocycline in SIADH was first reported in 1975, 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. Demeclocycline used to be the drug of choice for treating SIADH. Meanwhile it might be superseded, now that

vasopressin receptor antagonist A vasopressin receptor antagonist (VRA) is an agent that interferes with action at the vasopressin receptors. Most commonly VRAs are used in the treatment of hyponatremia, especially in patients with congestive heart failure, liver cirrhosis or SIAD ...

s, such as tolvaptan, became available.

Contraindications

Like other tetracyclines, demeclocycline is contraindicated in children and pregnant or nursing women. All members of this class interfere with

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

development and may discolour

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, ...

Side effects and interactions

These are similar to those of other tetracyclines. Skin reactions with sunlight have been reported. Like only few other known tetracycline derivatives, demeclocycline causes nephrogenic diabetes insipidus. Furthermore demeclocycline might have psychotropic side effects similar to

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense soli ...

. Tetracyclines bind to cations, such as

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar ...

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

(when given orally), and

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...

, rendering them insoluble and inadsorbable for the gastrointestinal tract. Demeclocycline should not be taken with food (particularly milk and other dairy products) or antacids.

Mechanism of action

As with related tetracycline antibiotics, demeclocycline acts by binding to the

30S The prokaryotic small ribosomal subunit, or 30 S subunit, is the smaller subunit of the 70S ribosome found in prokaryotes. It is a complex of the 16S ribosomal RNA (rRNA) and 19 proteins. This complex is implicated in the binding of transfer R ...

ribosomal subunit to inhibit binding of aminoacyl tRNA which impairs protein synthesis by bacteria. It is bacteriostatic (it impairs bacterial growth, but does not kill bacteria directly). Demeclocycline inhibits the renal action of

antidiuretic hormone Human vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It then travel ...

by interfering with the intracellular

second messenger cascade Second messengers are intracellular signaling molecules released by the cell in response to exposure to extracellular signaling molecules—the first messengers. (Intercellular signals, a non-local form or cell signaling, encompassing both first me ...

(specifically, inhibiting

adenylyl cyclase Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction: :A ...

activation) after the hormone binds to vasopressin V₂ receptors in the

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...

. Exactly how demeclocycline does this has yet to be elucidated, however.

Brand names

Brand names include Declomycin, Declostatin, Ledermycin, Bioterciclin, Deganol, Deteclo, Detravis, Meciclin, Mexocine, and Clortetrin.

References

{{Oxytocin and vasopressin receptor modulators Tetracycline antibiotics Chloroarenes Carboxamides Drugs with unknown mechanisms of action Triketones Nephrotoxins