Ofrex-tz

Uses

Ofloxacin Eye: It is used for the treatment of external ocular infections such as acute & sub-acute conjunctivitis, keratitis, kerato-conjunctivitis, blepharo-conjunctivitis, blepharitis, corneal ulcer and pre-operative prophylaxis in ocular surgery.

Ofloxacin Ear: It is used for the treatment of external ear infections (otitis externa) and certain middle ear infections (otitis media).

Ofloxacin Oral/Injection are used for the treatment of adults with mild to moderate infections caused by susceptible strains.

• Lower Respiratory Tract: Acute bacterial exacerbation of chronic bronchitis lung abscess, pneumonia.
• Gastrointestinal Tract: Enteric fever, shigellosis.
• Multi-drug-resistant Tuberculosis.
• Skin and skin structures: Uncomplicated skin and skin structure infections.
• Sexually Transmitted Diseases: Acute, Uncomplicated urethral and cervical gonorrhoea. Nongonococcal urethritis and cervicitis. Mixed infections of the urethra and cervix.
• Urinary tract: Uncomplicated Urinary Tract Infections, Complicated urinary tract infections.

Trichomoniasis: Tinidazole is used for the treatment of trichomoniasis caused by Trichomonas vaginalis. The organism should be identified by appropriate diagnostic procedures. Because trichomoniasis is a sexually transmitted disease with potentially serious sequelae, partners of infected patients should be treated simultaneously in order to prevent re-infection.

Giardiasis: Tinidazole is used for the treatment of giardiasis caused by Giardia duodenalis in both adults and pediatric patients older than three years of age. Sections or subsections omitted from the full prescribing information are not listed.

Amebiasis: Tinidazole is used for the treatment of intestinal amebiasis and amebic liver abscess caused by Entamoeba histolytica in both adults and pediatric patients older than three years of age. It is not used for the treatment of asymptomatic cystpassage.

Bacterial Vaginosis: Tinidazole is used for the treatment of bacterial vaginosis (formerly referred to as Haemophilus vaginitis, Gardnerella vaginitis, nonspecific vaginitis, or anaerobic vaginosis) in non-pregnant women.

Other pathogens commonly associated with vulvovaginitis such as Trichomonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae, Candida albicans and Herpes simplex virus should be ruled out.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Tinidazole and other antibacterialdrugs, Tinidazole should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Ofrex-tz is also used to associated treatment for these conditions: Acute Bacterial Exacerbation of Chronic Bronchitis (ABECB), Acute Otitis Media, Bacterial Infections, Cervicitis, Community Acquired Pneumonia (CAP), Complicated Urinary Tract Infection, Conjunctivitis, Epididymitis, Hansen's Disease, Nongonococcal urethritis, Otitis Externa, Prostatitis, Skin and Subcutaneous Tissue Bacterial Infections, Spontaneous Bacterial Peritonitis (SBP), Traveler's Diarrhea, Ulcerative keratitis, Acute Pelvic inflammatory disease, Acute, uncomplicated Gonorrhea, Chronic suppurative Otitis media, Uncomplicated CystitisAmebiasis, Bacterial Vaginosis (BV), Candidal Vulvovaginitis, Giardiasis, Mixed Vaginal Infections, Nongonococcal urethritis, Sexually Transmitted Disease (STD), Trichomonas Vaginalis Infection, Trichomoniasis

How Ofrex-tz works

Ofloxacin acts on DNA gyrase and toposiomerase IV, enzymes which, like human topoisomerase, prevents the excessive supercoiling of DNA during replication or transcription. By inhibiting their function, the drug thereby inhibits normal cell division.

Tinidazole is a prodrug and antiprotozoal agent. The nitro group of tinidazole is reduced in Trichomonas by a ferredoxin-mediated electron transport system. The free nitro radical generated as a result of this reduction is believed to be responsible for the antiprotozoal activity. It is suggested that the toxic free radicals covalently bind to DNA, causing DNA damage and leading to cell death. The mechanism by which tinidazole exhibits activity against Giardia and Entamoeba species is not known, though it is probably similar.

Dosage

Ofrex-tz dosage

Ofloxacin Eye: Instill 1 drop in the affected eye(s) every 2 to 4 hours for the first two days and then 4 times daily. The length of treatment should not exceed ten days.

Ofloxacin Ear: Instill 1-2 drops in the affected ear(s) twice daily or as needed.

Ofloxacin Intravenous (Adult):

• Skin and soft tissue infections: 400 mg bid infused over at least 1 hr.
• Complicated urinary tract infections: 200 mg daily by infusion over at least 30 min. Max: 400 mg bid infused over at least 1 hr.
• Lower respiratory tract infections, Septicaemia: 200 mg bid by infusion over at least 30 min. Max: 400 mg bid infused over at least 1 hr.

Ofloxacin Oral (Adult):

General dosage recommendations: The dose of ofloxacin is determined by the type and severity of the infection. The dosage range for adults is 200 mg to 800 mg daily. Up to 400 mg may be given as a single dose, preferably in the morning, larger doses should be given as two divided doses. Ofloxacin tablets should be swallowed with liquid; they should not be taken within two hours of intake of magnesium/aluminium containing antacids or iron preparations since reduction of absorption of ofloxacin can occur.

• Enteric fever: For adults 200 mg, every 12 hours, for 5 days. For children 15 mg/kg/day in 2 divided doses for 3 days.
• Shigellosis: 400 mg single dose.
• Multi-drug-resistant tuberculosis: 400 mg twice daily along with conventional anti-tuberculosis drugs.
• Lower respiratory tract infection: 400 mg daily, increasing, if necessary, to 400 mg twice daily.
• Uncomplicated Urinary Tract Infections: A single dose of 200/400 mg.
• Uncomplicated urethral and cervical gonorrhoea: A single dose of 400 mg.
• Non-gonococcal urethral and cervicitis: 400 mg daily in single or divided doses.
• Complicated Urinary Tract Infection: 200/400 mg/day for 7 days.

Children: Ofloxacin is usually not indicated for use in children or growing adolescents.

Elderly: No adjustment of dosage is required in the elderly.

Prevention of Postoperative Infections :

• Adult: A single oral dose of 2g approximately 12 hours before surgery.
• Children less than 12 years: Data are not available to allow dosage recommendations for children below the age of 12 years in the prophylaxis of anaerobic infections.

Trichomoniasis: a single 2 g oral dose taken with food. Treat sexual partners with the same dose and at the same time Giardiasis:

• Adults: a single 2 g dose taken with food.
• Pediatric patients older than three years of age: a single dose of 50 mg/kg (up to 2 g) with food

Amebiasis, Intestinal:

• Adults: 2 g per day for 3 days with food.
• Pediatric patients older than three years of age: 50 mg/kg/day (up to 2 g per day) for 3 days with food

Amebic liver abscess:

• Adults: 2 g per day for 3-5 days with food.
• Pediatric patients older than three years of age: 50 mg/kg/day (up to 2 g per day) for 3-5 days with food

Bacterial vaginosis: Non-pregnant, adult women: 2 g once daily for 2 days taken with food, or 1 g once daily for 5 days taken with food.

May be taken with or without food. Avoid antacids or supplements containing Fe or Zn within 2 hr before or after ofloxacin. Ensure adequate hydration.

Should be taken with food. Take during or immediately after meals.

Side Effects

Ofloxacin Eye: Transient ocular irritation, burning, stinging, redness, itching or photophobia have been reported.

Ofloxacin Ear: Mild irritation or mild discomfort in the ear may occur. Symptoms of an allergic reaction include rash, itching, swelling or trouble breathing.

Ofloxacin tablet or injection is generally well tolerated and clinical side-effects of ofloxacin has been quite low. Among the adverse effects gastrointestinal and central nervous systems' reactions are common. Nausea, rash, vomiting, abdominal pain, diarrhoea and gastrointestinal distress are the gastrointestinal adverse effects. Common central nervous system reactions are headache, dizziness and insomnia.

Reported side effects have generally been infrequent, mild and self-limiting. Side effects from the gastrointestinal tract include nausea, vomiting, anorexia, diarrhoea and metallic taste. Hypersensitivity reactions, occasionally severe, may occur in rare cases in the form of skin rash, pruritis, urticaria and angioneurotic oedema. As with related compounds, tinidazole may produce transient leukopenia. Other rarely reported side-effects are headache, tiredness, furry tongue and dark urine.

Toxicity

LD₅₀=5450 mg/kg (orally in mice)

There are no reported overdoses with tinidazole in humans. In acute studies with mice and rats, the LD 50 for mice was generally > 3,600 mg/kg for oral administration and was > 2,300 mg/kg for intraperitoneal administration. In rats, the LD 50 was > 2,000 mg/kg for both oral and intraperitoneal administration.

Precaution

Patients being treated with Ofloxacin should not expose themselves unnecessarily to strong sunlight and should avoid UV rays. Caution is recommended if the drug is to be used in psychotic patients or in-patients with a history of psychiatric disease.

Prolonged use of eye drops & ear drops may result in overgrowth of non-susceptible organisms and secondary infection respectively.

Compounds of similar chemical structure have produced various neurological disturbances such as dizziness, vertigo, uncoordination, and ataxia. If, during therapy with tinidazole, abnormal neurological signs develop, therapy should be discontinued. Use in Pregnancy & Lactation: Tinidazole is contraindicated during the first trimester of pregnancy. While there is no evidence that tinidazole is harmful during the late stages of pregnancy, its use during the last two trimesters requires that the potential benefits outweigh the possible risk to mother and foetus. Tinidazole is excreted in breast milk in concentrations similar to those seen in serum. Tinidazole can be detected in breast milk for up to 72 hours following administration. Interruption of breast-feeding is recommended during tinidazole therapy and for 3 days following the last dose.

Interaction

Antacids containing magnesium, aluminium or calcium may decrease absorption of ofloxacin. Iron or Zinc may decrease oral absorption of ofloxacin.

The following interactions were reported with metronidazole, which is chemically-related to tinidazole.

Alcohol, disulfiram: Avoid during tinidazole use and for 3 days afterward because cramps, nausea, vomiting, headaches, and flushing may occur.

Anticoagulants, oral (eg, warfarin): Anticoagulant effects may be increased. Anticoagulant dose may need to be adjusted during coadministration and for up to 8 days after discontinuation.

Cholestyramine: Bioavailability of tinidazole may be decreased. Cyclosporine, lithium, tacrolimus: Levels may be elevated by tinidazole, increasing the risk of toxicity.

Drugs that induce CYP3A4 (eg, fosphenytoin, phenobarbital, phenytoin, rifampin): May increase metabolism of tinidazole, decreasing plasma levels and therapeutic effect.

Drugs that inhibit CYP3A4 (eg, cimetidine, ketoconazole): May prolong t½ and decrease tinidazole Cl, increasing plasma levels and risk of adverse reactions.

Fluorouracil: Cl may be decreased by tinidazole, increasing the risk of adverse reactions

Fosphenytoin, phenytoin: The t½ may be prolonged and Cl reduced by tinidazole, increasing the risk of adverse reactions.

Oxytetracycline: Therapeutic effect of tinidazole may be decreased.

Volume of Distribution

• 50 L

Elimination Route

Bioavailability of ofloxacin in the tablet formulation is approximately 98%

Rapidly and completely absorbed under fasting conditions. Administration with food results in a delay in T_max of approximately 2 hours and a decline in C_max of approximately 10% and an AUC of 901.6 ± 126.5 mcg hr/mL.

Half Life

9 hours

The elimination half-life is 13.2±1.4 hours and the plasma half-life is 12 to 14 hours.

Elimination Route

Ofloxacin is mainly eliminated by renal excretion, where between 65% and 80% of an administered oral dose of ofloxacin is excreted unchanged via urine within 48 hours of dosing. About 4-8% of an ofloxacin dose is excreted in the feces and the drug is minimally subject to biliary excretion.

Tinidazole crosses the placental barrier and is secreted in breast milk. Tinidazole is excreted by the liver and the kidneys. Tinidazole is excreted in the urine mainly as unchanged drug (approximately 20-25% of the administered dose). Approximately 12% of the drug is excreted in the feces.

Pregnancy & Breastfeeding use

Use in pregnancy: There are no adequate and well-controlled studies in pregnant women. This drug should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Use in lactation: It is not known whether Ofloxacin is excreted in human milk. Cautions should be taken when Ofloxacin eye & ear drops is administered during lactation.

Pregnancy Category C. Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.

Contraindication

It is contraindicated in patients who are hypersensitive to Ofloxacin or any other component of Ofloxacin (Eye/Ear Drops).

Ofloxacin tablet injection should not be used in-patients with known hypersensitivity to 4-fluoroquinolone antibacterials. It is contraindicated in-patients with a history of epilepsy or with a lowered seizure threshold. Ofloxacin is usually contraindicated in children or growing adolescents and in pregnant or breast feeding women.

As with other compounds of similar structure, tinidazole, is contraindicated in patients having, or with a history of, blood dyscrasias although no persistent haematological abnormalities have been noted in clinical or animal studies. Tinidazole should be avoided in patients with organic neurological disorders. Tinidazole should not be administered to patients with known hypersensitivity to the compound.

Special Warning

Renal Impairment:

• CrCl <20 and patients on haemodialysis or peritoneal dialysis: 100 mg 24 hrly following usual initial dose.
• CrCl 20-50: Reduce dose by half 24 hrly following usual initial dose.

Hepatic Impairment:Severe: Reduce dose. Max: 400 mg daily

Renal Impairment: Haemodialysis: Additional dose equal to half the usual dose at the end of haemodialysis.

Acute Overdose

Symptoms: Confusion, dizziness, impairment of consciousness, convulsive seizures, GI reactions (e.g. nausea, mucosal erosions).

Management: Symptomatic and supportive treatment. Remove any unabsorbed drug by gastric lavage or admin of adsorbants and Na sulfate. Antacids are recommended for protection of gastric mucosa. Elimination may be increased by forced diuresis.

Storage Condition

Store between 15-30° C. Protect from light.

Store at room temperature & protected from light.

Innovators Monograph

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