Brand
name: TERRAMYCIN (Oxytetracycline)
Generic Name: oxytetracycline hydrochloride
TERRAMYCIN (Oxytetracycline) Description
Oxytetracycline is a product of the metabolism of Streptomyces rimosus
and is one of the family of tetracycline antibiotics. A 1 percent solution
in water is acidic (pH about 2.5). Its potency is affected in solutions
more acid than pH 2 and it is rapidly destroyed by alkali hydroxides.
Oxytetracycline diffuses readily through the placenta into the fetal
circulation, into the pleural fluid and, under some circumstances,
into the cerebrospinal fluid. It appears to be concentrated in the
hepatic system and excreted in the bile, so that it appears in the
feces, as well as in the urine, in a biologically active form.
Inert ingredients in the formulation are: glucosamine hydrochloride;
hard gelatin capsules (which may contain Red 3, Yellow 10 and other
inert ingredients); magnesium stearate; sodium lauryl sulfate; starch.
ACTIONS
Oxytetracycline is primarily bacteriostatic and is thought to exert
its antimicrobial effect by the inhibition of protein synthesis. Oxytetracycline
is active against a wide range of gram-negative and gram-positive organisms.The
drugs in the tetracycline class have closely similar antimicrobial
spectra, and cross resistance among them is common. Microorganisms
may be considered susceptible if the M.I.C. (minimum inhibitory concentration)
is not more than 4.0 mcg/ml and intermediate if the M.I.C. is 4.0 to
12.5 mcg/ml.Susceptibility plate testing: A tetracycline disc may be
used to determine microbial susceptibility to drugs in the tetracycline
class. If the
Kirby-Bauer method of disc susceptibility testing is used, a 30 mcg
tetracycline disc should give a zone of at least 19 mm when tested
against a tetracycline-susceptible bacterial strain.Tetracyclines are
readily absorbed and are bound to plasma proteins in varying degree.
They are concentrated by the liver in the bile,
and excreted in the urine and feces at high concentrations and in a
biologically active form.
INDICATIONS
Oxytetracycline is indicated in infections caused by the following
microorganisms:
* Rickettsiae (Rocky Mountain spotted fever, typhus fever and the
typhus group, Q fever, rickettsialpox and tick fevers),
* Mycoplasma pneumoniae (PPLO, Eaton Agent),
* Agents of psittacosis and ornithosis,
* Agents of lymphogranuloma venereum and granuloma inguinale,
* The spirochetal agent of relapsing fever (Borrelia recurrentis).
The following gram negative microorganisms:
* Haemophilus ducreyi (chancroid),
* Pasteurella pestis, and Pasteurella tularensis,
* Bartonella bacilliformis,
* Bacteroides species,
* Vibrio comma and Vibrio fetus,
* Brucella species (in conjunction with streptomycin).
Because many strains of the following groups of microorganisms have
been shown to be resistant to tetracyclines, culture and susceptibility
testing are recommended.
Oxytetracycline is indicated for treatment of infections caused by
the following gram-negative microorganisms, when bacteriologic testing
indicates appropriate susceptibility to the drug:
* Escherichia coli,
* Enterobacter aerogenes (formerly Aerobacter aerogenes), * Shigella species, * Mima species and Herellea species,
* Haemophilus influenzae (respiratory infections), * Klebsiella species (respiratory
and urinary infections). Oxytetracycline is indicated for treatment of infections
caused by the following gram-positive microorganisms when bacteriologic testing
indicates appropriate susceptibility to the drug:
Streptococcus species:
Up to 44 percent of strains of Streptococcus pyogenes and 74 percent
of Streptococcus faecalis have been found to be resistant to tetracycline
drugs. Therefore, tetracyclines should not be used for streptococcal
disease unless the organism has been demonstrated to be sensitive.For
upper respiratory infections due to Group A beta-hemolytic streptococci,
penicillin is the usual drug of choice, including prophylaxis of rheumatic
fever.
Diplococcus pneumoniae,Staphylococcus aureus, skin and soft-tissue
infections. Oxytetracycline is not the drug of choice in the treatment
of any type of staphylococcal
infections.
In severe acne, the tetracyclines may be useful adjunctive therapy.
Tetracyclines are indicated in the treatment of trachoma, although
the infectious agent is not always eliminated, as judged by immunofluorescence.
Inclusion conjunctivitis may be treated with oral tetracyclines or
with a combination of oral and topical agents.
Contraindications
This drug is contraindicated in persons who have shown hypersensitivity
to any of the tetracyclines.
Warnings
If renal impairment exists, even usual oral or parenteral doses may
lead to excessive systemic accumulation of the drug and possible liver
toxicity. Under such conditions, lower than usual total doses are indicated
and, if therapy is prolonged, serum level determinations of the drug
may be advisable.
Photosensitivity manifested by an exaggerated sunburn reaction has
been observed in some individuals taking tetracyclines. Patients apt
to be exposed to direct sunlight or ultraviolet light should be advised
that this reaction can occur with tetracycline drugs, and treatment
should be discontinued at the first evidence of skin erythema.
The antianabolic action of the tetracyclines may cause an increase
in BUN. While this is not a problem in those with normal renal function,
in patients with significantly impaired function, higher serum levels
of tetracycline may lead to azotemia, hyperphosphatemia, and acidosis.
Results of animal studies indicate that tetracyclines cross the placenta,
are found in fetal tissues and can have toxic effects on the developing
fetus (often related to retardation of skeletal development). Evidence
of embryotoxicity has also been noted in animals treated early in pregnancy.
All tetracyclines form a stable calcium complex in any bone forming
tissue. A decrease in the fibula growth rate has been observed in prematures
given oral tetracycline in doses of 25 mg/kg every 6 hours. This reaction
was shown to be reversible when the drug was discontinued.
Tetracyclines are present in the milk of lactating women who are taking
a drug in this class.
Precautions TERRAMYCIN (Oxytetracycline)
As with other antibiotic preparations, use of this drug may result
in overgrowth of nonsusceptible organisms, including fungi. If superinfection
occurs, the antibiotic should be discontinued and appropriate therapy
instituted.
In venereal diseases when coexistent syphilis is suspected, a dark
field examination should be done before treatment is started and the
blood serology repeated monthly for at least 4 months.Because tetracyclines
have been shown to depress plasma prothrombin activity, patients who
are on anticoagulant therapy may require downward
adjustment of their anticoagulant dosage.In long term therapy, periodic
laboratory evaluation of organ systems, including hematopoietic, renal
and hepatic studies should be performed.All infections due to Group
A beta-hemolytic streptococci should be treated for at least 10 days.
Since bacteriostatic drugs may interfere with the bactericidal action
of penicillin, it is advisable to avoid giving tetracycline in conjunction
with penicillin.
Adverse Reactions TERRAMYCIN (Oxytetracycline)
Gastrointestinal: anorexia, nausea, vomiting, diarrhea, glossitis,
dysphagia, enterocolitis, and inflammatory lesions (with monilial overgrowth)
in the anogenital region. These reactions have been caused by both
the oral and parenteral administration of tetracyclines. Rare instances
of esophagitis and esophageal ulcerations have been reported in patients
receiving capsule and tablet forms of drugs in the tetracycline class.
Most of these patients took medications immediately before going to
bed. (See DOSAGE AND ADMINISTRATION.)
Skin: maculopapular and erythematous rashes. Exfoliative dermatitis
has been reported but is uncommon. Photosensitivity is discussed above.
(See WARNINGS.)
Renal toxicity: Rise in BUN has been reported and is apparently dose
related. (See WARNINGS.)
Hypersensitivity reactions: Urticaria, angioneurotic edema, anaphylaxis,
anaphylactoid purpura, pericarditis and exacerbation of systemic lupus
erythematosus.
Bulging fontanels in infants and benign intracranial hypertension
in adults have been reported in individuals receiving full therapeutic
dosages. These conditions disappeared rapidly when the drug was discontinued.
Blood: Hemolytic anemia, thrombocytopenia, neutropenia and eosinophilia
have been reported.
When given over prolonged periods, tetracyclines have been reported
to produce brown-black microscopic discoloration of thyroid glands.
No abnormalities of thyroid function studies are known to occur.
TERRAMYCIN (Oxytetracycline) Dosage and Administration
Adults: Usual daily dose, 1–2 g divided in four equal doses,
depending on the severity of the infection.
For children above eight years of age: Usual daily dose, 10–20
mg per pound (25–50 mg/kg) of body weight divided in four equal
doses.
Therapy should be continued for at least 24–48 hours after symptoms
and fever have subsided.
For treatment of brucellosis, 500 mg oxytetracycline four times daily
for 3 weeks should be accompanied by streptomycin, 1 gram intramuscularly
twice daily the first week, and once daily the second week.
For treatment of uncomplicated gonorrhea, when penicillin is contraindicated,
tetracycline may be used for the treatment of both males and females
in the following divided dosage schedule: 1.5 grams initially followed
by 0.5 gram q.i.d. for a total of 9.0 grams.
For treatment of syphilis, a total of 30–40 grams in equally
divided doses over a period of 10–15 days should be given. Close
follow-up, including laboratory tests, is recommended.Administration
of adequate amounts of fluid along with capsule and tablet forms of
drugs in the tetracycline class is recommended to wash
down the drugs and reduce the risk of esophageal irritation and ulceration.
Concomitant therapy: Antacids containing aluminum, calcium, or magnesium
impair absorption and should not be given to patients taking oral tetracyclines.Food
and some dairy products also interfere with absorption. Oral forms
of tetracyclines should be given 1 hour before or 2 hours after
meals. Pediatric oral dosage forms should not be given with milk formulas
and should be given at least 1 hour prior to feeding.
Total dosage should
be decreased by reduction of recommended individual doses and/or by
extending time intervals between doses.
In the treatment of streptococcal infections, a therapeutic dose of
oxytetracycline should be administered for at least 10 days.
