Demeclocycline is officially indicated for the treatment of various types of bacterialinfections.[3] It is used as an antibiotic in the treatment of Lyme disease,[4]acne,[5] and bronchitis.[6] Resistance, though, is gradually becoming more common,[7] and demeclocycline is now rarely used for treatment of infections.[8][9]
It is widely used (though off-label in many countries including the United States) 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.[10] Physiologically, this works by reducing the responsiveness of the collecting tubule cells to ADH.[11]
The use in SIADH actually relies on a side effect; demeclocycline induces nephrogenic diabetes insipidus (dehydration due to the inability to concentrate urine).[10][12][13]
The use of demeclocycline in SIADH was first reported in 1975,[14] 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treatment at the time.[15] Demeclocycline used to be the drug of choice for treating SIADH.[13] Meanwhile, it might be superseded, now that vasopressin receptor antagonists, such as tolvaptan, became available.[15]
Like 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.[9]
The side effects are similar to those of other tetracyclines. Skin reactions with sunlight have been reported.[15] Like only few other known tetracycline derivatives, demeclocycline causes nephrogenic diabetes insipidus.[16] Furthermore, demeclocycline might have psychotropic side effects similar to lithium.[17]
Tetracyclines bind to cations, such as calcium, iron (when given orally), and magnesium, rendering them insoluble and inadsorbable for the gastrointestinal tract. Demeclocycline should not be taken with food (particularly milk and other dairy products) or antacids.[9]
As with related tetracycline antibiotics, demeclocycline acts by binding to the 30S 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).[1][7]
^ abChopra I, Hawkey PM, Hinton M (March 1992). "Tetracyclines, molecular and clinical aspects". The Journal of Antimicrobial Chemotherapy. 29 (3): 245–277. doi:10.1093/jac/29.3.245. PMID1592696.
^Rosner B (2007). "The Antibiotic Rotational Protocol". The Top 10 Lyme Disease Treatments: Defeat Lyme Disease with the Best of Conventional and Alternative Medicine. BioMed Publishing. pp. 84, 86. ISBN9780976379713.
^"Ad Hoc Committee report: systemic antibiotics for treatment of acne vulgaris: efficacy and safety". Archives of Dermatology. 111 (12): 1630–1636. December 1975. doi:10.1001/archderm.1975.01630240086015. PMID128326.
^Beatson JM, Marsh BT, Talbot DJ (1985). "A clinical comparison of pivmecillinam plus pivampicillin (Miraxid) and a triple tetracycline combination (Deteclo) in respiratory infections treated in general practice". The Journal of International Medical Research. 13 (4): 197–202. doi:10.1177/030006058501300401. PMID3930309. S2CID23485353.
^Cherrill DA, Stote RM, Birge JR, Singer I (November 1975). "Demeclocycline treatment in the syndrome of inappropriate antidiuretic hormone secretion". Annals of Internal Medicine. 83 (5): 654–656. doi:10.7326/0003-4819-83-5-654. PMID173218.
^Mørk A, Geisler A (January 1995). "A comparative study on the effects of tetracyclines and lithium on the cyclic AMP second messenger system in rat brain". Progress in Neuro-Psychopharmacology & Biological Psychiatry. 19 (1): 157–169. doi:10.1016/0278-5846(94)00112-U. PMID7708928. S2CID36219362.
