A-Tetra

Uses

A-Tetra ointment is used for followings-

• Treatment of bacterial conjunctivitis
• Treatment of trachoma (by preference use oral azithromycin for this indication)
• Prevention of chlamydial and gonococcal neonatal conjunctivitis

A-Tetra is the drug of choice in the following infections :

• Ricketsial infection (Rocky Mountain spotted fever, endemic and scrub typhus fever and human ehrlichiosis).
• Mycoplasma pneumoniae infections in adults. Outbreaks of pneumonia caused by this organism are common in barracks and institutions. Most cases occur in children and young adults. Maculopapular rashes, haemolytic anaemia and meningo-encephalitis occur rarely.
• Chlamydial Infections: Chlamydia psittaci: This organism is the cause of psittacosis (ornithosis), a systemic illness contracted from infected birds. The pneumonia associated with it may be extensive, and severe systemic upset and death are common.Headache is a prominent early symptom.
• Non-gonococcal or non specific urethritis: Inflammation of the urethra not resulting from gonococcal, chlamydial, or other specific infectious agents.
• Lyme disease
• Brucellosis
• Miscellaneous infections, including granuloma inguinale, cholera, glanders, relapsing fever and V. vulnifians.

Other common uses of tetracycline include the following:

• Urinary Tract Infections with susceptible organisms (including the acute urethral syndrome in women).
• Bronchitis in patients with known underlying chronic lung diseases.
• Pelvic inflammatory disease and other sexually transmitted diseases (STDs) regimen.
• Travelers diarrhoea.
• Acne vulgaris
• Prostatitis.
• As an alternative agent in the penicillin allergic patient with syphilis.
• Anaerobic infections with susceptible organisms.

A-Tetra is also used to associated treatment for these conditions: Acinetobacter infection, Acne Rosacea, Actinomycosis, Anthrax, Bacterial Infections, Bartonellosis, Brucellosis, Campylobacter Infection, Chancroid, Chlamydial Infections, Cholera, Conjunctivitis, Inclusion, Cystitis, Endometritis, Entamoebic histolytica infection, Escherichia infections, Gonorrhoea, Granuloma Inguinale, Helicobacter Pylori Infection, Infection, Infection, Bacteroides, Klebsiella Infections, Listeria infection, Lower respiratory tract infection bacterial, Lymphogranuloma Venereum, Necrotizing ulcerative gingivostomatitis, Neisseria Gonorrhoeae Infection, Nephritis, Ornithosis, Plague, Prostatitis, Psittacosis, Q Fever, Relapsing Fever, Rickettsialpox, Rocky Mountain Spotted Fever, Severe Acne, Shigella Infection, Skin and Subcutaneous Tissue Bacterial Infections, Skin infection caused by Staphylococcus aureus, Syphilis, Trachoma, Tularemia, Typhus, Urinary Tract Infection, Yaws, Bacterial upper respiratory tract infections, Clostridia infections, Grade 1, grade 2, grade 3, grade 4 Urinary Tract Infection

How A-Tetra works

A-Tetra passively diffuses through porin channels in the bacterial membrane and reversibly binds to the 30S ribosomal subunit, preventing binding of tRNA to the mRNA-ribosome complex, and thus interfering with protein synthesis.

Dosage

A-Tetra dosage

The usual adult oral dosage of A-Tetra is 1-2 g daily given in 2-4 divided doses. The usual oral dosage of A-Tetra for children older than 8 years of age in 25-50 mg/kg daily given in 2-4 divided doses. Alternatively some clinicians recommended that children should receive 0.6-1.2 g/m2 daily.

A-Tetra should be taken preferably one hour before or 2 hours after meals.

Some specific indications along with some information on dosage is given below:

Acne vulgaris: 250 mg four times daily or 500 mg 12 hourly for 1 week; 125-250 mg for several weeks or months.Duration of therapy is determined by individual progress

Acutestaphylococcal infections: 1-2 g daily in divideddoses for 10-14 days

Acute streptococcal infections:1-2 g daily in divided doses for 10 days.Prolonged therapy is needed to avoid risk of rheumatic fever or glomerulonephritis

Amoebiasis:1 g daily in four divided doses or 500 mg 12 hourly for 7 days.Given in association with amoebicidal agents

Brucellosis: 500 mg four times daily plus 1 g streptomycin twice daily for 1 week ; then 500 mg four times daily (no streptomycin) for 1 week.Prolonged therapy is necessary to avoid relapse

Subacute bacterial endocarditis:1-2 g daily in divided doses for 6 weeks.Usually given in combination with a bactericidal agent

Syphilis:Total 30-40 g given in divided doses over 10-15 days.Serology and spinal fluid examination should follow the administration of tetracycline

Wash the eyes with boiled and cooled water before each application. Use sterile sodium chloride 0.9% for newborns. Apply tetracycline 1% into the conjunctival sac of both eyes:

• Conjunctivitis: one application 2 times daily for 7 days
• Trachoma: one application 2 times dailyfor 6 weeks
• Prevention of neonatal conjunctivitis: one single application immediately after birth

Side Effects

Teeth and bone: A-Tetra can cause depression of bone growth, permanent graybrown discoloration of the teeth and enamel hypoplasia when given during tooth development (i.e. during the later half of pregnancy, during infancy and in childhood).

Hypersensitivity reactions such as anaphylaxis, urticaria and rashes are uncommon. Photosensitivity reactions consisting of a red rash on areas exposed to intense sunlight can occur with A-Tetra.

Gastrointestinal effects: Epigastric distress and nausea are commonly seen after oral administration, and these symptoms are somewhat dose related. Vomiting can occur.

Accentuated prerenal azotemia: A-Tetra appears to aggravate pre-existing renal failure by inhibiting protein synthesis, which increases the azotemia from amino acid metabolism.

Superinfections with oral and anogenital candidiasis are relatively common in patients taking A-Tetra.

Esophageal ulcerations: In most cases, the patients were taking the capsules with little or no fluid before going to bed. To help minimize this, oral doses should be given with adequate amounts of fluid.

Eye/Ear: Burning, irritation, visual disturbances, superinfections, photosensitivity, hypersensitivity

Toxicity

LD₅₀=808mg/kg (orally in mice)

Precaution

Care should be taken if A-Tetra Hydrochloride is given to patients with impaired liver function and high doses should be avoided. Potentiality hepatotoxic drugs (including erythromycin, chloramphenicol, isoniazide and sulphonamides) should not be given concomitantly.

Hepatic impairment. Avoid exposure to sunlight. Periodic evaluation of renal, hepatic and haematological system during prolonged therapy.

Interaction

Impaired absorption with antacids containing divalent and trivalent cations (e.g. Al, Ca, Mg), Fe, Zn and Na bicarbonate preparations, kaolin-pectin, bismuth subsalicylate, sucralfate, strontium ranelate, colestipol and colestyramine. May interfere with the bactericidal action of penicillin. May potentiate the effect of anticoagulants. May decrease efficacy of oral contraceptives. Nephrotoxic effects may be exacerbated by diuretics or other nephrotoxic drugs. May increase the hypoglycaemic effect of insulin and sulfonylureas in patients with DM. May increase toxic effects of ergot alkaloids and methotrexate.

Food Interaction

• Avoid milk and dairy products.
• Take on an empty stomach. Take at least 1 hour before or 2 hours after meals.
• Take with a full glass of water.

[Moderate] ADJUST DOSING INTERVAL: Administration with food, particularly dairy products, significantly reduces tetracycline absorption.

The calcium content of these foods forms nonabsorbable chelates with tetracycline.

MANAGEMENT: A-Tetra should be administered one hour before or two hours after meals.

A-Tetra multivitamins interaction

[Moderate] GENERALLY AVOID: The bioavailability of oral tetracyclines and iron salts may be significantly decreased during concurrent administration.

Therapeutic failure may result.

The proposed mechanism is chelation of tetracyclines by the iron cation, forming an insoluble complex that is poorly absorbed from the gastrointestinal tract.

In ten healthy volunteers, simultaneous oral administration of ferrous sulfate 200 mg and single doses of various tetracyclines (200 mg to 500 mg) resulted in reductions in the serum levels of methacycline and doxycycline by 80% to 90%, oxytetracycline by 50% to 60%, and tetracycline by 40% to 50%.

In another study, 300 mg of ferrous sulfate reduced the absorption of tetracycline by 81% and that of minocycline by 77%.

Conversely, the absorption of iron has been shown to be decreased by up to 78% in healthy subjects and up to 65% in patients with iron depletion when ferrous sulfate 250 mg was administered with tetracycline 500 mg.

Available data suggest that administration of iron 3 hours before or 2 hours after a tetracycline largely prevents the interaction with most tetracyclines except doxycycline.

Due to extensive enterohepatic cycling, iron binding may occur with doxycycline even when it is given parenterally.

It has also been shown that when iron is administered up to 11 hours after doxycycline, serum concentrations of doxycycline may still be reduced by 20% to 45%.

Coadministration of a tetracycline with any iron-containing product should be avoided if possible.

Otherwise, patients should be advised to stagger the times of administration by at least three to four hours, although separating the doses may not prevent the interaction with doxycycline.

A-Tetra Drug Interaction

Unknown: aripiprazole, zolpidem, aspirin, lorazepam, duloxetine, omega-3 polyunsaturated fatty acids, escitalopram, atorvastatin, pregabalin, esomeprazole, acetaminophen, fluoxetine, montelukast, levothyroxine, acetaminophen, cyanocobalamin, ascorbic acid, cholecalciferol, alprazolam, cetirizine

A-Tetra Disease Interaction

Major: colitisModerate: hepatotoxicity, renal dysfunction, esophageal irritation

Elimination Route

Bioavailability is less than 40% when administered via intramuscular injection, 100% intravenously, and 60-80% orally (fasting adults). Food and/or milk reduce GI absorption of oral preparations of tetracycline by 50% or more.

Half Life

6-12 hours

Elimination Route

They are concentrated by the liver in the bile and excreted in the urine and feces at high concentrations in a biologically active form.

Pregnancy & Breastfeeding use

A-Tetra should not be used during pregnancy because of the risk of hypertoxicity in the mother as well as the effects on the developing foetus. Use in pregnancy potentially during breast-feeding and in children up to the age of 8, or some authorise say 12 years, may result in impaired bone growth and permanent discoloration of the child's teeth.

Contraindication

A-Tetra Hydrochloride is contraindicated in patients hypersensitive to any of the member of tetracycline groups, since cross-sensitivity may occur A-Tetra Hydrochloride should be avoided in patients with systemic lupus erythematosus. A-Tetra Hydrochloride is considered to be contraindicated in renal impairment, particularly if severe ; if it must be given, doses should be reduced.

Storage Condition

Store between 20-25° C.

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