«PRESCRIBING INFORMATION Pr VIBRAMYCIN* CAPSULES doxycycline hyclate capsules USP doxycycline 100 mg Pr VIBRA-TABS* FILM COATED TABLETS doxycycline ...»
Since bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid giving VIBRAMYCIN/VIBRA-TABS, or any other tetracycline, in conjunction with penicillin.
There have been anecdotal reports that concurrent use of tetracyclines may render oral contraceptives less effective.
The concurrent use of tetracycline and Penthrane (methoxyflurane) has been reported to result in fatal renal toxicity.
Concomitant use of isotretinoin and doxycycline should be avoided because isotretinoin is also known to cause benign intracranial hypertension (pseudotumor cerebri) (see PRECAUTIONS).
Drug Laboratory Test Interactions False elevations of urinary catecholamine levels may occur due to interference with the fluorescence test.
Cases of esophagitis and esophageal ulcer, sometimes severe, in patients receiving capsule and tablet form of VIBRAMYCIN/VIBRA-TABS (doxycycline hyclate) have been reported (see WARNINGS, PRECAUTIONS, DOSAGE AND ADMINISTRATION,
INFORMATION FOR THE PATIENT).
AUTONOMIC NERVOUS SYSTEM:Flushing.
HYPERSENSITIVITYHypersensitivity reactions consisting of urticaria, angioedema, anaphylactic reaction, anaphylactoid reaction, Henoch-Schonlein Purpura, dyspnea, hypotension, pericarditis, peripheral edema, serum sickness, tachycardia and exacerbation of systemic lupus erythematosus have been reported.
Maculopapular and erythematous rashes, photosensitivity reaction, photo-onycholysis, erythema multiforme, Stevens-Johnson syndrome and Toxic epidermal necrolysis have been reported. Dermatitis exfoliative has also been reported but is uncommon (see WARNINGS, skin).
MUSCULO-SKELETAL:Arthralgia and myalgia. 13
CENTRAL NERVOUS SYSTEM:
Headache, fontanelle bulging in infants and benign intracranial hypertension (pseudotumor cerebri) in adults. In relation to benign intracranial hypertension, symptoms included blurring of vision, scotomata and diplopia. Permanent visual loss has been reported (see PRECAUTIONS).
There have been reports of hepatotoxicity (including hepatic failure, autoimmune hepatitis and cholestasis) and hepatic function abnormal. As with other tetracyclines, hepatitis, elevation of SGOT or SGPT values have been reported, the significance of which is not known.
Hemolytic anemia, thrombocytopenia, neutropenia, eosinophilia, leukopenia.
IMMUNE SYSTEM DISORDERS:
Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)
INVESTIGATIONS (Renal Function Analyses) Blood urea increased (apparently dose related) has been reported.
Vaginal candidiasis (see PRECAUTIONS)
When given over prolonged periods tetracyclines have been reported to produce brownblack microscopic discolouration of the thyroid gland. Abnormalities of thyroid function have not been shown to date (see TOXICOLOGY, Subacute Toxicity).
Specific information on symptoms or treatment of overdosage with VIBRAMYCIN/VIBRA-TABS (doxycycline hyclate) is not available. In case of overdosage, discontinue medication. Treatment, therefore, should be symptomatic and gastric lavage may be considered for overdosage with the oral preparation. Dialysis does not alter serum half-life and thus would not be of benefit in treating cases of overdosage.
For management of suspected drug overdose contact your regional Poison Control Centre.
EXCEEDING THE RECOMMENDED DOSAGE MAY RESULT IN AN INCREASED
INCIDENCE OF SIDE EFFECTS.
Adults The recommended dosage of oral VIBRAMYCIN/VIBRA-TABS for the majority of susceptible infections is a single loading dose of 200 mg on the first day of treatment followed by a maintenance dosage of 100 mg once daily at the same time each day thereafter.
When used in streptococcal infections, therapy should be continued for 10 days to prevent the development of rheumatic fever or glomerulonephritis.
For treatment of uncomplicated acute gonococcal infections, the recommended dosage is 200 mg starting and 100 mg in the evening, the first day, followed by 100 mg b.i.d. for 3 days.
For treatment of uncomplicated urethral, endocervical, or vaginal infections in adults associated with Chlamydia trachomatis and Ureaplasma urealyticum: 100 mg, by mouth, twice a day for at least 10 days.
No alteration in recommended dosage schedule need be made when treating patients with impaired renal function.
VIBRAMYCIN Capsules and VIBRA-TABS Film Coated Tablets should be given with or after a meal in order to minimize the possibility of gastric upset. Antacids and iron preparations impair absorption and should not be given concomitantly to patients taking oral VIBRAMYCIN/VIBRA-TABS.
VIBRAMYCIN CAPSULES: each blue, hard gelatin capsule contains: doxycycline hyclate equivalent to doxycycline 100 mg. Also contains microcrystalline cellulose, magnesium stearate/sodium lauryl sulfate. Capsule shell contains gelatin, sulfur dioxide, titanium dioxide and FD & C Blue #1 dye. Supplied in plastic bottles (high density polyethylene) of 50 capsules.
VIBRA-TABS: each orange film coated tablet contains doxycycline hyclate equivalent to doxycycline 100 mg. Also contains microcrystalline cellulose, ethylcellulose, hypromellose, magnesium stearate/sodium lauryl sulfate, propylene glycol, talc, titanium dioxide, FD & C Yellow #6, and aluminum hydroxide. Supplied in plastic bottles (high density polyethylene) of 100 tablets.
AVAILABILITYVIBRAMYCIN CAPSULES 100 mg are available as blue hard gelatin capsules imprinted in black with “VIBRA/PFIZER 095” containing doxycycline hyclate equivalent to 100 mg of doxycycline, supplied in bottles of 50.
VIBRA-TABS FILM COATED TABLETS 100 mg are available as orange film coated tablets containing doxycycline hyclate equivalent to 100 mg of doxycycline, supplied in bottles of 100.
STORAGE VIBRAMYCIN CAPSULES (doxycycline hyclate) 100 mg and VIBRA-TABS (doxycycline hyclate) 100 mg. Store at a temperature 15-30°C; protect from light. Dispense in a light-resistant container.
Doxycycline is a broad spectrum antibiotic and has been shown to be active in vitro against
the following Gram-negative, Gram-positive and other micro-organisms:
Corynebacterium diphtheriae Bacillus anthracis Bacillus subtilis Neisseria gonorrhoeae Neisseria catarrhalis Escherichia coli Enterobacter aerogenes Pseudomonas aeruginosa Haemophilus influenzae Serratia spp.
Mycoplasma pneumoniae Chlamydia trachomatis Ureaplasma urealyticum 19 The drugs in the tetracycline class have closely similar antimicrobial spectra, and cross-resistance among them is common.
SUSCEPTIBILITY TESTINGThe Kirby-Bauer method of disc susceptibility testing (using the 30 g doxycycline disc) and dilution susceptibility should be interpreted according to the criteria in TABLE 1.
Serum levels of doxycycline administered orally follow a similar pattern to those obtained with equivalent dosages administered intravenously as shown in TABLE 2. Peak serum levels were slightly higher and occurred earlier following intravenous administration than for oral administration (see TABLE 2).
20 TABLE 2 Serum levels (mg/L) after oral and I.V. infusion over 60 minutes (0.5 mg/mL) of a total daily dose of 200 mg of doxycycline hyclate on the first day (100 mg every 12 hours) and a dose of 100 mg on the second and third day of administration (22 Male Volunteers/Group).
____ ____ ____ 0:05 2.455 0.000.001 1:00 1.608 1.206.01 2:00 1.551 1.643 3:00 1.421 1.482 16:00 1.131 1.124 11:00 0.800 0.815 ____ ____ ____ 13:00 2.397 1.107.001 15:00 2.130 2.000 24:00 1.468 1.663.088 ____ ____ ____ 35:00 1.734 1.725 48:00 1.159 1.078 ____ ____ ____ 48:05 3.658 1.124.001 49:00 2.945 2.147.001 50:00 2.848 2.406.056 51:00 2.760 2.436 54:00 2.150 1.989 59:00 1.665 1.516 72:00 1.021 0.945 83:00 0.700 0.709 96:00 0.426 0.399 107:00 0.247 0.234
Doxycycline was rapidly and almost completely absorbed following oral administration.
The absorption of doxycycline was not significantly influenced by ingestion of food or milk (see TABLE 3).
Doxycyline is approximately 93% protein bound. The serum half-life of doxycycline is 18 hours. Doxycycline is excreted in the urine (approximately 35-40% of the administered dose) and in the bile. The volume of distribution is approximately 0.7 L/kg. Hemodialysis does not alter the serum half-live.
Excretion of doxycycline by the kidney is about 40%/72 hours in individuals with normal renal function (creatinine clearance about 75 mL/min.). This percentage excretion may fall to a range as low as 1-5%/72 hours in individuals with severe renal insufficiency (creatinine clearance below 10 mL/min.). The serum half-life of doxycycline is not increased, nor does it accumulate in the blood of patients with impaired renal function.
The intraperitoneal LD50' s of doxycycline in weanling and newborn rats are 262 (222-309) and 300 (275-327) mg/kg, respectively.
b) Subacute Toxicity One to 2 1/2-month subacute toxicity studies were conducted in rats, hamsters, dogs and monkeys. Doxycycline induced a yellow fluorescence (under ultraviolet light) of bone, teeth, kidney and/or liver, in all animal species tested. In rats, doxycycline produced no toxic effects in doses of up to 500 mg/kg/day for 30 days. In hamsters, doxycycline in dosages of 500 or 250 mg/kg/day produced weight loss and early death, but the 50 mg/kg level (for 30 days) was nontoxic. In dogs, doxycycline in dosages of 250 mg/kg/day for one month produced discoloration of the thyroid gland with the presence of intracytoplasmic granules in follicular acini and occasional amorphous body formation within follicular colloid.
Certain biochemical, functional and histological changes of the liver occurred in the dogs (but not in the rats, hamsters, or monkeys) receiving doxycycline for 30 days at dosage levels of 250 and 50 mg/kg/day, but not at the 25 mg/kg/day level. The biochemical changes in the blood were elevations of alkaline phosphatase, SGPT 23 and/or BSP retention. Histologic changes were confined to bile ductular proliferation and hepatocellular intracytoplasmic inclusion bodies and Kupffer cells swollen with PAS-positive granular material. These changes in the dog were reversible upon drug withdrawal.
Monkeys which received doxycycline at dosages of 25 and 50 mg/kg/day for 1 1/2 to 2 1/2 months showed mild yellow ultraviolet fluorescence of liver, kidney and bone, and the presence of small amounts of intracytoplasmic granular material in the thyroid gland.
c) Chronic Toxicity In an 18-month chronic toxicity study, rats were fed diets containing doxycycline at levels to provide daily drug intake of 500, 250, 50 and 0 mg/kg. Slight depression of weight gains in some rats receiving the 500 mg/kg/day dose occurred during the middle third of the study. The usual yellow ultraviolet fluorescence of bone, teeth and/or kidneys was seen in rats receiving all levels of doxycycline for 6, 12 or 18 months. Dark to light brown discoloration of the thyroid gland was also noted in rats receiving doxycycline for 12 months at levels of 500 and 250 mg/kg/day, and at 18 months at all levels. The only other change noted was depletion of hepatic glycogen in four rats receiving the highest dose level for 12 months.
Beagle dogs received doxycycline at levels of 10 and 100 mg/kg, six days per week.
Moderate to marked elevations of alkaline phosphatase and SGPT (occasionally SGOT) were observed in animals receiving doxycycline, 100 mg/kg/day. One of two dogs receiving doxycycline, 100 mg/kg/day, displayed mild bile ductular proliferation and hepatocellular inclusion bodies after 5 months (biopsy sample) and 12 months (necropsy sample). Administration of doxycycline for 5 and 12 months at a level of 100 mg/kg/day and for 12 months at a level of 10 mg/kg caused black and brownish discoloration of the thyroid gland, respectively, with intracytoplasmic granules. Other changes included vasodilatation and focal areas of necrosis of the mucosa of the 24 pyloric and fundic stomach of dogs, and yellow ultraviolet fluorescence of teeth and bones of animals at 100 mg/kg/day dose levels of doxycycline.
Additional groups of 4 beagles each received doxycycline in dosages of 5, 1 and 0 mg/kg/day for 6 months. The only abnormal findings were slight elevations of SGPT values in 3 dogs at the 5 mg/kg level at 180 days.