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Declomycin Side Effects

Generic name: demeclocycline

Medically reviewed by Last updated on Jun 21, 2022.

Note: This document contains side effect information about demeclocycline. Some dosage forms listed on this page may not apply to the brand name Declomycin.

Applies to demeclocycline: oral tablets.

Side effects include:

GI effects (anorexia, nausea, vomiting, diarrhea); maculopapular and erythematous rash; dose-related BUN increase; hypersensitivity reactions.

For Healthcare Professionals

Applies to demeclocycline: oral tablet.


Phototoxic reactions appear to be more common with demeclocycline (the active ingredient contained in Declomycin) than with other tetracyclines. These reactions may reoccur up to 3 weeks after demeclocycline is discontinued. Patients receiving demeclocycline should avoid sun exposure and use sunscreen for about 3 weeks after completing demeclocycline therapy.[Ref]

Dermatologic reactions associated with tetracyclines have included photosensitivity, maculopapular rash, erythematous rash, erythema multiforme, exfoliative dermatitis, fixed drug eruption, Stevens-Johnson syndrome, and skin and mucous membrane pigmentation.[Ref]


Demeclocycline has been used to produce nephrogenic diabetes insipidus in patients with hyponatremia associated with the syndrome of inappropriate anti-diuretic hormone (SIADH) secretion. Demeclocycline use for this indication may be limited by increases in BUN and serum creatinine, which appear to be dose-related but are reversible when the drug is discontinued. Decreases in glomerular filtration rate and creatinine clearance, as well as azotemia, have been reported in patients with congestive heart failure, cirrhosis, and cancer treated with demeclocycline (the active ingredient contained in Declomycin) Azotemia has been associated with increases in demeclocycline serum concentrations. In one report of three patients with cirrhosis, the decrease in inulin clearance associated with demeclocycline ranged from 63% to 78%.[Ref]

Renal effects have included the inhibition of antidiuretic hormone (ADH) in the renal tubules. This action produces nephrogenic diabetes insipidus, resulting in polyuria and an inability to concentrate urine. Nephrogenic diabetes insipidus occurs at dosages between 600 to 1200 mg per day, generally after approximately 5 days of therapy, and reverses within approximately one week after therapy is discontinued. Tetracyclines have also been associated with acute renal failure and increased BUN.[Ref]


Gastrointestinal side effects associated with tetracyclines have included nausea, anorexia, vomiting, diarrhea, glossitis, dysphagia, enterocolitis, pancreatitis, anogenital inflammation, and moniliasis. Esophageal ulceration has been reported in patients given demeclocycline (the active ingredient contained in Declomycin) without proper fluid when in a supine position. Tooth discoloration has been reported in pediatric patients and rarely in adults.[Ref]

Nervous system

Nervous system side effects associated with tetracyclines have included dizziness, headache, tinnitus, visual disturbances, and pseudotumor cerebri.[Ref]


Hypersensitivity reactions associated with tetracyclines have included urticaria, angioneurotic edema, polyarthralgia, anaphylaxis, anaphylactoid purpura, pericarditis, exacerbation of systemic lupus erythematosus, lupus-like syndrome, and pulmonary infiltrations with eosinophilia.[Ref]


Hematologic side effects associated with tetracyclines have included hemolytic anemia, thrombocytopenia, neutropenia, and eosinophilia.[Ref]


Hepatic side effects associated with tetracyclines have included increased liver enzymes, hepatic toxicity, hepatitis, and liver failure.[Ref]


Genitourinary side effects associated with tetracyclines have included penile lesions and balanitis.[Ref]


The long-term use of tetracyclines has been associated with microscopic brown-black discoloration of the thyroid gland. Abnormal thyroid function has rarely been reported.[Ref]


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2. Kahn G, Legg JK "Recrudescence of acute photosensitivity following short-term steroid therapy." Arch Dermatol 103 (1971): 94-7

3. Bethell HJ "Photo-onycholysis caused by demethylchlortetracycline." Br Med J 2 (1977): 96

4. "Product Information. Declomycin (demeclocycline)." Lederle Laboratories (2001):

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6. Cherrill DA, Stote RM, Birge JR, Singer I "Demeclocycline treatment in the syndrome of inappropriate antidiuretic hormone secretion." Ann Intern Med 83 (1975): 654-6

7. Singer I, Rotenberg D "Demeclocycline-induced nephrogenic diabetes insipidus. In-vivo and in- vitro studies." Ann Intern Med 79 (1973): 679-83

8. Roth H, Becker KL, Shalhoub RJ, Katz S "Nephrotoxicity of demethylchlortetracycline hydrochloride. A prospective study." Arch Intern Med 120 (1967): 433-5

9. Trump DL "Serious hyponatremia in patients with cancer: management with demeclocycline." Cancer 47 (1981): 2908-12

10. Geheb M, Cox M "Renal effects of demeclocycline." JAMA 243 (1980): 2519-20

11. Miller PD, Linas SL, Schrier RW "Plasma demeclocycline levels and nephrotoxicity. Correlation in hyponatremic cirrhotic patients." JAMA 243 (1980): 2513-5

12. Kirkpatrick R "Demeclocycline and renal insufficiency." JAMA 239 (1978): 616

13. Hayek A, Ramirez J "Demeclocycline-induced diabetes insipidus." JAMA 229 (1974): 676-7

14. Oster JR, Epstein M "Demeclocycline-induced renal failure." Lancet 1 (1977): 52

15. Perks WH, Walters EH, Tams IP, Prowse K "Demeclocycline in the treatment of the syndrome of inappropriate secretion of antidiuretic hormone." Thorax 34 (1979): 324-7

16. Carrilho F, Bosch J, Arroyo V, Mas A, Viver J, Rodes J "Renal failure associated with demeclocycline in cirrhosis." Ann Intern Med 87 (1977): 195-7

17. Goldsmith SR "Current treatments and novel pharmacologic treatments for hyponatremia in congestive heart failure." Am J Cardiol 95(9A) (2005): 14-23

18. Furey WW, Tan C "Anaphylactic shock due to oral demethylchlortetracycline." Ann Intern Med 70 (1969): 357-8

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.