Oxytetracycline is a product of the metabolism of Streptomyces rimosus and is one of the family of tetracycline antibiotics.
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.
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: 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 an oxytetracycline-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.
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,
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:
Enterobacter aerogenes (formerly Aerobacter aerogenes ),
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:
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.
Staphylococcus aureus , skin and soft tissue infections.
Oxytetracycline is not the drug of choice in the treatment of any type of staphylococcal infections.
When penicillin is contraindicated, tetracyclines are alternative drugs in the treatment of infections due to:
Treponema pallidum and Treponema pertenue (syphilis and yaws),
Fusobacterium fusiforme (Vincent's infection),
In acute intestinal amebiasis, the tetracyclines may be a useful adjunct to amebicides.
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.
This drug is contraindicated in persons who have shown hypersensitivity to any of the tetracyclines.
THE USE OF TETRACYCLINES DURING TOOTH DEVELOPMENT (LAST HALF OF PREGNANCY, INFANCY, AND CHILDHOOD TO THE AGE OF 8 YEARS) MAY CAUSE PERMANENT DISCOLORATION OF THE TEETH (YELLOW-GRAY-BROWN). This adverse reaction is more common during long term use of the drugs but has been observed following repeated short term courses. Enamel hypoplasia has also been reported. TETRACYCLINES, THEREFORE, SHOULD NOT BE USED IN THIS AGE GROUP UNLESS OTHER DRUGS ARE NOT LIKELY TO BE EFFECTIVE OR ARE CONTRAINDICATED.
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. This hazard is of particular importance in the parenteral administration of tetracyclines to pregnant or postpartum patients with pyelonephritis. When used under these circumstances, the blood level should not exceed 15 mcg/ml and liver function tests should be made at frequent intervals. Other potentially hepatotoxic drugs should not be prescribed concomitantly.
(In the presence of renal dysfunction, particularly in pregnancy, intravenous tetracycline therapy in daily doses exceeding 2 grams has been associated with deaths due to liver failure.)
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 this drug may lead to azotemia, hyperphosphatemia, and acidosis.
The product contains sodium formaldehyde sulfoxylate which serves as an antioxidant. Upon oxidation, this compound can form a potential sulfiting agent. Sulfiting agents may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. The over-all prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in nonasthmatic people.
Usage in pregnancy. (See above " " about use during tooth development.)
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.
Usage in newborns, infants, and children. (See above " " about use during tooth development).
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.
As with all intramuscular preparations, Terramycin (oxytetracycline) Intramuscular Solution should be injected well within the body of a relatively large muscle. ADULTS: The preferred sites are the upper outer quadrant of the buttock, (i.e., gluteus maximus), and the mid-lateral thigh. CHILDREN: It is recommended that intramuscular injections be given preferably in the mid-lateral muscles of the thigh. In infants and small children the periphery of the upper outer quadrant of the gluteal region should be used only when necessary, such as in burn patients, in order to minimize the possibility of damage to the sciatic nerve.
The deltoid area should be used only if well developed such as in certain adults and older children, and then only with caution to avoid radial nerve injury. Intramuscular injections should not be made into the lower and mid-thirds of the upper arm. As with all intramuscular injections, aspiration is necessary to help avoid inadvertent injection into a blood vessel.
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.
Local irritation may be present after intramuscular injection. The injection should be deep, with care taken not to injure the sciatic nerve nor inject intravascularly.
Gastrointestinal: 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.
Skin: maculopapular and erythematous rashes. Exfoliative dermatitis has been reported but is uncommon. Photosensitivity is discussed above. (See " ").
Renal toxicity: Rise in BUN has been reported and is apparently dose related. (See " ").
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: 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.
Adults: The usual daily dose is 250 mg administered once every 24 hours or 300 mg given in divided doses at 8 to 12 hour intervals.
For children above eight years of age: 15-25 mg/kg of body weight up to a maximum of 250 mg per single daily injection. Dosage may be divided and given at 8 to 12 hour intervals.
Intramuscular therapy should be reserved for situations in which oral therapy is not feasible.
The intramuscular administration of oxytetracycline produces lower blood levels than oral administration in the recommended dosages. Patients placed on intramuscular oxytetracycline should be changed to the oral dosage form as soon as possible. If rapid, high blood levels are needed, oxytetracycline should be administered intravenously.
In patients with renal impairment: (See " ") Total dosage should be decreased by reduction of recommended individual doses and/or by extending time intervals between doses.
Terramycin (oxytetracycline) Intramuscular Solution is available as follows:
250 mg/2ml--in 2 ml pre-scored glass ampules, packages of 5 (NDC 0049-0770-09).
100 mg/2ml--in 2 ml pre-scored glass ampules, packages of 5 (NDC 0049-0760-09).
50 mg/ml--in 10 ml multiple dose vials, packages of 5 (NDC 0049-0750-77).
Revised March 1987 70-1051-00-2