Demeclocycline is officially indicated for the treatment of various types ofbacterialinfections.[3] It is used as an antibiotic in the treatment ofLyme disease,[4]acne,[5] andbronchitis.[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 (thoughoff-label in many countries including the United States) in the treatment ofhyponatremia (low bloodsodium concentration) due to thesyndrome 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 inducesnephrogenic 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 thanlithium 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treatment at the time.[15] Demeclocycline used to be the drug of choice for treating SIADH.[13] Meanwhile, it might be superseded, now thatvasopressin receptor antagonists, such astolvaptan, became available.[15]
Likeother tetracyclines, demeclocycline is contraindicated in children and pregnant or nursing women. All members of this class interfere withbone development and may discolourteeth.[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 havepsychotropic side effects similar tolithium.[17]
Tetracyclines bind tocations, such ascalcium,iron (when given orally), andmagnesium, rendering them insoluble and nonadsorbable for the gastrointestinal tract. Demeclocycline should not be taken with food (particularly milk and other dairy products) orantacids.[9]
As with related tetracycline antibiotics, demeclocycline acts by binding to the30S ribosomal subunit to inhibit binding of aminoacyl tRNA which impairsprotein synthesis by bacteria. It isbacteriostatic (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.
^"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.
