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DESCRIPTION

Loracarbef is a synthetic b-lactam antibiotic of the carbacephem class for oral administration. Chemically, carbacephems differ from cephalosporin-class antibiotics in the dihydrothiazine ring where a methylene group has been substituted for a sulfur atom.

The chemical name for loracarbef is: (6R,7S)-7-[(R)-2-amino-2-phenylacetamido]-3-chloro-8-oxo-1-azabicyclo[4.2.0]oct-2-ene-2- carboxylic acid, monohydrate.

It is a white to off-white solid with a molecular weight of 367.8. The empirical formula is C16H16ClN3O4·H2O.

Lorabid (loracarbef) Pulvules and Lorabid (loracarbef) for Oral Suspension are intended for oral administration only.

Each Pulvule contains loracarbef equivalent to 200 mg (0.57 mmol) or 400 mg (1.14 mmol) anhydrous loracarbef activity. They also contain cornstarch, dimethicone, F Dy & C blue No. 2, gelatin, iron oxides, magnesium stearate, titanium dioxide, and other inactive ingredients.

After reconstitution, each 5 ml of Lorabid for Oral Suspension contains loracarbef equivalent to 100 mg (0.286 mmol) or 200 mg (0.57 mmol) anhydrous loracarbef activity. The suspensions also contain cellulose, F Dy & C red No. 40, flavors, methylparaben, propylparaben, simethicone emulsion, sodium carboxymethylcellulose, sucrose, and xanthan gum.

INDICATIONS

Loracarbef is indicated in the treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms in the conditions listed below. (As recommended dosages, durations of therapy, and applicable patient populations vary among these infections, please see DOSAGE AND ADMINISTRATION for specific recommendations.)

Lower Respiratory Tract: Secondary Bacterial Infection of Acute Bronchitis caused by S. pneumoniae, H. influenzae(including b-lactamase-producing strains), or M. catarrhalis (including b-lactamase-producing strains).

Acute Bacterial Exacerbations of Chronic Bronchitis: caused by S. pneumoniae, H. influenzae (including b-lactamase-producing strains), or M. catarrhalis (including b-lactamase-producing strains).

Pneumonia: caused by S. pneumoniae or H. influenzae (non-b-lactamase-producing strains only). Data are insufficient at this time to establish efficacy in patients with pneumonia caused by b-lactamase-producing strains of H. influenzae.

Upper Respiratory Tract: Otitis Media† caused by S. pneumoniae, H. influenzae (including b-lactamase-producing strains), M. catarrhalis (including b-lactamase-producing strains), or S. pyogenes.

Acute Maxillary Sinusitis:† caused by S. pneumoniae, H. influenzae (non-b-lactamase-producing strains only), or M. catarrhalis (including b-lactamase-producing strains). Data are insufficient at this time to establish efficacy in patients with acute maxillary sinusitis caused by b-lactamase-producing strains of H. influenzae.

† NOTE: In a patient population with significant numbers of b-lactamase-producing organisms, loracarbef's clinical cure and bacteriological eradication rates were somewhat less than those observed with a product containing a b-lactamase inhibitor. Loracarbef's decreased potential for toxicity compared to products containing b-lactamase inhibitors along with the susceptibility patterns of the common microbes in a given geographic area should be taken into account when considering the use of an antimicrobial (see CLINICAL STUDIES.)

Pharyngitis and Tonsillitis: caused by S. pyogenes. (The usual drug of choice in the treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever, is penicillin administered by the intramuscular route. Loracarbef is generally effective in the eradication of S. pyogenes from the nasopharynx; however, data establishing the efficacy of loracarbef in the subsequent prevention of rheumatic fever are not available at present.) For information on use in pediatric patients, see PRECAUTIONS, Pediatric Use.

Skin and Skin Structure: Uncomplicated Skin and Skin Structure Infections caused by S. aureus (including penicillinase-producing strains) or S. pyogenes. Abscesses should be surgically drained as clinically indicated.

Urinary Tract: Uncomplicated Urinary Tract Infections (cystitis) caused by E. coli or S. saprophyticus*.

NOTE: In considering the use of loracarbef in the treatment of cystitis, loracarbef's lower bacterial eradication rates and lower potential for toxicity should be weighed against the increased eradication rates and increased potential for toxicity demonstrated by some other classes of approved agents (see CLINICAL STUDIES.)

Uncomplicated Pyelonephritis: caused by E. coli.

*Although treatment of infections due to this organism in this organ system demonstrated a clinically acceptable overall outcome, efficacy was studied in fewer than 10 infections.

Culture and susceptibility testing should be performed when appropriate to determine the causative organism and its susceptibility to loracarbef. Therapy may be started while awaiting the results of these studies. Once these results become available, antimicrobial therapy should be adjusted accordingly.

DOSAGE AND ADMINISTRATION

Loracarbef is administered orally either at least 1 hour prior to eating or at least 2 hours after eating. The recommended dosages, durations of treatment, and applicable patient populations are described in TABLE 13.

Renal Impairment: Loracarbef may be administered to patients with impaired renal function. The usual dose and schedule may be employed in patients with creatinine clearance levels of 50 ml/min or greater. Patients with creatinine clearance between 10 and 49 ml/min may be given half of the recommended dose at the usual dosage interval, or the normal recommended dose at twice the usual dosage interval. Patients with creatinine clearance levels less than 10 ml/min may be treated with the recommended dose given every 3 to 5 days; patients on hemodialysis should receive another dose following dialysis.

When only the serum creatinine is available, the following formula (based on sex, weight, and age of the patient) may be used to convert this value into creatinine clearance (CLcr, ml/min). The equation assumes the patient's renal function is stable.

Males = [(weight in kg) ´ (140 - age)] ¸ [72 ´ serum creatinine (mg/100 ml)] Females = (0.85) ´ (above value) Reconstitution Directions for Oral Suspension

• 50 ml: Add 30 ml of water in 2 portion to the dry mixture in the bottle. Shake well after each addition.
• 75 ml: Add 45 ml of water in 2 portions to the dry mixture in the bottle. Shake well after each addition.
• 100 ml: Add 60 ml of water in 2 portions to the dry mixture in the bottle. Shake well after each addition.

After mixing, the suspension may be kept at room temperature, 59° to 86°F (15° to 30°C), for 14 days without significant loss of potency. Keep tightly closed. Discard unused portion after 14 days.

HOW SUPPLIED

Lorabid (loracarbef) Pulvules: 200 mg, is blue and gray with 3170.

Lorabid (loracarbef) Pulvules: 400 mg, is blue and pink with 3171.

Keep tightly closed. Store at controlled room temperature, 59° to 86°F (15° to 30°C). Protect from heat.

Pulves oral suspension is strawberry bubble gum flavor.

PRODUCT LISTING

REFERENCES

1. National Committee for Clinical Laboratory Standards, M2-A4 performance standards for antimicrobial disk susceptibility tests. ed 4, Villanova, PA, April, 1990.

2. National Committee for Clinical Laboratory Standards, M7-A2 methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically, ed 2, Villanova, PA, April, 1990.

SIDE EFFECTS

The nature of adverse reactions to loracarbef are similar to those observed with orally administered b-lactam antimicrobials. The majority of adverse reactions observed in clinical trials were of a mild and transient nature; 1.5% of patients discontinued therapy because of drug-related adverse reactions. No one reaction requiring discontinuation accounted for >0.03% of the total patient population; however, of those reactions resulting in discontinuation, gastrointestinal events (diarrhea and abdominal pain) and skin rashes predominated.

All Patients

The following adverse events, irrespective of relationship to drug, have been reported following the use of loracarbef in clinical trials. Incidence rates (combined for all dosing regimens and dosage forms) were less than 1% for the total patient population, except as otherwise noted:

Gastrointestinal: The most commonly observed adverse reactions were related to the gastrointestinal system. The incidence of gastrointestinal adverse reactions increased in patients treated with higher doses. Individual event rates included diarrhea, 4.1%; nausea, 1.9%; vomiting 1.4%; abdominal pain, 1.4%; and anorexia.

Hypersensitivity: Hypersensitivity reactions including, skin rashes (1.2%), urticaria, pruritus, and erythema multiforme.

Central Nervous System: Headache (2.9%), somnolence, nervousness, insomnia, and dizziness.

Hemic and Lymphatic Systems: Transient thrombocytopenia, leukopenia, and eosinophilia.

Hepatic: Transient elevations in AST (SGOT), ALT (SGPT), and alkaline phosphatase.

Renal: Transient elevations in BUN and creatinine.

Cardiovascular System: Vasodilatation.

Genitourinary: Vaginitis (1.3%), vaginal moniliasis (1.1%).

As with other b-lactam antibiotics, the following potentially severe adverse experiences have been reported rarely with loracarbef in worldwide post-marketing surveillance: anaphylaxis, hepatic dysfunction including cholestasis, prolongation of the prothrombin time with clinical bleeding in patients taking anticoagulants, and Stevens-Johnson syndrome.

Pediatric Patients

The incidences of several adverse events, irrespective of relationship to drug, following treatment with loracarbef were significantly different in the pediatric population and the adult population as follows (TABLE 12):

b-Lactam Antimicrobial Class Labeling

The following adverse reactions and altered laboratory test results have been reported in patients treated with b-lactam antibiotics:

Adverse Reactions: Allergic reactions, aplastic anemia, hemolytic anemia, hemorrhage, agranulocytosis, toxic epidermal necrolysis, renal dysfunction, toxic nephropathy. As with other b-lactam antibiotics, serum sickness-like reactions have been reported rarely with loracarbef.

Several b-lactam antibiotics have been implicated in triggering seizures, particularly in patients with renal impairment when the dosage was not reduced. If seizures associated with drug therapy should occur, the drug should be discontinued. Anticonvulsant therapy can be given if clinically indicated.

Altered Laboratory Tests: Increased prothrombin time, positive direct Coombs' test, elevated LDH, pancytopenia, and neutropenia.

DRUG INTERACTIONS

Probenecid: As with other b-lactam antibiotics, renal excretion of loracarbef is inhibited by probenecid and resulted in an approximate 80% increase in the AUC for loracarbef (see CLINICAL PHARMACOLOGY).

WARNINGS

BEFORE THERAPY WITH LORACARBEF IS INSTITUTED, CAREFUL INQUIRY SHOULD BE MADE TO DETERMINE WHETHER THE PATIENT HAS HAD PREVIOUS HYPERSENSITIVITY REACTIONS TO LORACARBEF, CEPHALOSPORINS, PENICILLINS, OR OTHER DRUGS. IF THIS PRODUCT IS TO BE GIVEN TO PENICILLIN-SENSITIVE PATIENTS, CAUTION SHOULD BE EXERCISED BECAUSE CROSS-HYPERSENSITIVITY AMONG b-LACTAM ANTIBIOTICS HAS BEEN CLEARLY DOCUMENTED AND MAY OCCUR IN UP TO 10% OF PATIENTS WITH A HISTORY OF PENICILLIN ALLERGY. IF AN ALLERGIC REACTION TO LORACARBEF OCCURS, DISCONTINUE THE DRUG. SERIOUS ACUTE HYPERSENSITIVITY REACTIONS MAY REQUIRE THE USE OF EPINEPHRINE AND OTHER EMERGENCY MEASURES, INCLUDING OXYGEN, INTRAVENOUS FLUIDS, INTRAVENOUS ANTIHISTAMINES, CORTICOSTEROIDS, PRESSOR AMINES, AND AIRWAY MANAGEMENT, AS CLINICALLY INDICATED.

Pseudomembranous colitis has been reported with nearly all antibacterial agents and may range from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents.

Treatment with broad-spectrum antibiotics alters the normal flora of the colon and may permit overgrowth of clostridia. Studies indicate that a toxin produced by Clostridium difficile is a primary cause of "antibiotic-associated colitis."

After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to discontinuation of drug alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation, and treatment with an antibacterial drug effective against C. difficile-associated colitis.

PRECAUTIONS

General: In patients with known or suspected renal impairment (see DOSAGE AND ADMINISTRATION), careful clinical observation and appropriate laboratory studies should be performed prior to and during therapy. The total daily dose of loracarbef should be reduced in these patients because high and/or prolonged plasma antibiotic concentrations can occur in such individuals administered the usual doses. Loracarbef, like cephalosporins, should be given with caution to patients receiving concurrent treatment with potent diuretics because these diuretics are suspected of adversely affecting renal function.

As with other broad-spectrum antimicrobials, prolonged use of loracarbef may result in the overgrowth of nonsusceptible organisms. Careful observation of the patient is essential. If superinfection occurs during therapy, appropriate measures should be taken.

Loracarbef, as with other broad-spectrum antimicrobials, should be prescribed with caution in individuals with a history of colitis.

Information for the Patient: Loracarbef should be taken either at least 1 hour prior to eating or at least 2 hours after eating a meal.

Carcinogenesis, Mutagenesis, and Impairment of Fertility: Although life-time studies in animals have not been performed to evaluate carcinogenic potential, no mutagenic potential was found for loracarbef in standard tests of genotoxicity, which included bacterial mutation tests and in vitro and in vivo mammalian systems. In rats, fertility and reproductive performance were not affected by loracarbef at doses up to 33 times the maximum human exposure in mg/kg (10 times the exposure based on mg/m2).

Pregnancy Category B: Reproduction studies have been performed in mice, rats, and rabbits at doses up to 33 times the maximum human exposure in mg/kg (4, 10, and 4 times the exposure, respectively, based on mg/m2) and have revealed no evidence of impaired fertility or harm to the fetus due to loracarbef. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Labor and Delivery: Loracarbef has not been studied for use during labor and delivery. Treatment should be given only if clearly needed.

Nursing Mothers: It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when loracarbef is administered to a nursing woman.

Pediatric Use: The safety and efficacy of Lorabid (loracarbef) have been established for children aged six months to twelve years for acute maxillary sinusitis based upon its approval in adults. Use of Lorabid (loracarbef) in pediatric patients is supported by pharmacokinetic and safety data in adults and children, and by clinical and microbiologic data from adequate and well-controlled studies of the treatment of acute maxillary sinusitis in adults and of acute otitis media with effusion in children. It is also supported by post-marketing adverse events surveillance. (See CLINICAL PHARMACOLOGY, INDICATIONS AND USAGE, ADVERSE REACTIONS, DOSAGE AND ADMINISTRATION, and CLINICAL STUDIES).

Geriatric Use: Healthy geriatric volunteers (³65 years old) with normal renal function who received a single 400-mg dose of loracarbef had no significant differences in AUC or clearance when compared to healthy adult volunteers 20 to 40 years of age. In clinical studies, when geriatric patients received the usual recommended adult doses, clinical efficacy and safety were comparable to results in nongeriatric adult patients. Because significant numbers of elderly patients have decreased renal function, evaluation of renal function in this population is recommended (see DOSAGE AND ADMINISTRATION.)

OVERDOSE

Signs and Symptoms: The toxic symptoms following an overdose of b-lactams may include nausea, vomiting, epigastric distress, and diarrhea.

Loracarbef is eliminated primarily by the kidneys. Forced diuresis, peritoneal dialysis, hemodialysis, or hemoperfusion have not been established as beneficial for an overdose of loracarbef. Hemodialysis has been shown to be effective in hastening the elimination of loracarbef from plasma in patients with chronic renal failure.

CONTRAINDICATIONS

Loracarbef is contraindicated in patients with known allergy to loracarbef or cephalosporin-class antibiotics.

CLINICAL PHARMACOLOGY

Loracarbef, after oral administration, was approximately 90% absorbed from the gastrointestinal tract. When capsules were taken with food, peak plasma concentrations were 50% to 60% of those achieved when the drug was administered to fasting subjects and occurred from 30 to 60 minutes later. Total absorption, as measured by urinary recovery and area under the plasma concentration versus time curve (AUC), was unchanged. The effect of food on the rate and extent of absorption of the suspension formulation has not been studied to date.

The pharmacokinetics of loracarbef were linear over the recommended dosage range of 200 to 400 mg, with no accumulation of the drug noted when it was given twice daily.

Average peak plasma concentrations after administration of 200-mg or 400-mg single doses of loracarbef as capsules to fasting subjects were approximately 8 to 14 mcg/ml, respectively, and were obtained within 1.2 hours after dosing. The average peak plasma concentration in adults following a 400-mg single dose of suspension was 17 mcg/ml and was obtained within 0.8 hour after dosing (see TABLE 1).

Following administration of 7.5 and 15 mg/kg single doses of oral suspension to children, average peak plasma concentrations were 13 and 19 mcg/ml, respectively, and were obtained within 40 to 60 minutes.

This increased rate of absorption (suspension > capsule) should be taken into consideration if the oral suspension is to be substituted for the capsule, and capsules should not be substituted for the oral suspension in the treatment of otitis media (see DOSAGE AND ADMINISTRATION).

The elimination half-life was an average of 1.0 h in patients with normal renal function. Concomitant administration of probenecid decreased the rate of urinary excretion and increased the half-life to 1.5 hours.

In subjects with moderate impairment of renal function (creatinine clearance 10 to 50 ml/min/1.73 m2), following a single 400-mg dose, the plasma half-life was prolonged to approximately 5.6 hours. In subjects with severe renal impairment (creatinine clearance