Clostridium difficile-associated diarrhea (CDAD) has been reported with nearly all antibacterial agents and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the flora of the colon and may permit overgrowth of C. difficile.
C. difficile produces toxins A and B which contribute to the development of CDAD. Hyper-toxin-producing strains of C. difficile cause increased morbidity and mortality, since these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary because CDAD has been reported to occur more than 2 months after the administration of antibacterial agents.
If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.
Development of Drug-Resistant Bacteria
Prescribing VIBATIV in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
As with other antibacterial drugs, use of VIBATIV may result in overgrowth of nonsusceptible organisms, including fungi. Patients should be carefully monitored during therapy. If superinfection occurs, appropriate measures should be taken.
QTc Prolongation
In a study involving healthy volunteers, doses of 7.5 and 15 mg/kg of VIBATIV prolonged the QTc interval [see Clinical Pharmacology (12.2)]. Caution is warranted when prescribing VIBATIV to patients taking drugs known to prolong the QT interval. Patients with congenital long QT syndrome, known prolongation of the QTc interval, uncompensated heart failure, or severe left ventricular hypertrophy were not included in clinical trials of VIBATIV. Use of VIBATIV should be avoided in patients with these conditions.
Coagulation Test Interference
Although telavancin does not interfere with coagulation, it interfered with certain tests used to monitor coagulation (Table 3), when conducted using samples drawn 0 to 18 hours after VIBATIV administration for patients being treated once every 24 hours. Blood samples for these coagulation tests should be collected as close as possible prior to a patient's next dose of VIBATIV. Blood samples for coagulation tests unaffected by VIBATIV may be collected at any time [see Drug Interactions (7.1)].
Table 3: Coagulation Tests Affected and Unaffected by Telavancin
Affected by Telavancin
|
Unaffected by Telavancin
|
Prothrombin time/international normalized ratio Activated partial thromboplastin time Activated clotting time Coagulation based factor X activity assay
|
Thrombin time Whole blood (Lee-White) clotting time Platelet aggregation study Chromogenic anti-factor Xa assay Functional (chromogenic) factor X activity assay Bleeding time D-dimer Fibrin degradation products
|
No evidence of increased bleeding risk has been observed in clinical trials with VIBATIV. Telavancin has no effect on platelet aggregation. Furthermore, no evidence of hypercoagulability has been seen, as healthy subjects receiving VIBATIV have normal levels of D-dimer and fibrin degradation products.
USE IN SPECIFIC POPULATIONS
Pregnancy
Teratogenic Effects: Pregnancy Category C
Pregnancy Exposure Registry
There is a pregnancy registry that monitors pregnancy outcomes in women exposed to VIBATIV during pregnancy. Physicians are encouraged to register pregnant patients, or pregnant women may enroll themselves in the VIBATIV pregnancy registry by calling 1-855-MED-THRX (1-855-633-8479).
Fetal Risk Summary
All pregnancies have a background risk of birth defects (about 3%), pregnancy loss (about 15%), or other adverse outcomes regardless of drug exposure.
There are no data on VIBATIV use in pregnant women. In 3 animal species, VIBATIV exposure during pregnancy at clinically relevant doses caused reduced fetal weights and increased rates of digit and limb malformations in offspring. These data raise concern about potential adverse developmental outcomes in humans (see
Data
).
Clinical Considerations
Given the lack of human data and the risks suggested by animal data, avoid using VIBATIV in pregnant women unless the benefits to the patient outweigh the potential risks to the fetus.
Data
Human Data
There are no data on human pregnancies exposed to VIBATIV.
Animal Data
In embryo-fetal development studies in rats, rabbits, and minipigs, telavancin demonstrated the potential to cause limb and skeletal malformations when given intravenously during the period of organogenesis at doses up to 150, 45, or 75 mg/kg/day, respectively. These doses resulted in exposure levels approximately 1- to 2-fold the human exposure (AUC) at the maximum clinical recommended dose. Malformations observed at <1% (but absent or at lower rates in historical or concurrent controls), included brachymelia (rats and rabbits), syndactyly (rats, minipigs), adactyly (rabbits), and polydactyly (minipigs). Additional findings in rabbits included flexed front paw and absent ulna, and in the minipigs included misshapen digits and deformed front leg. Fetal body weights were decreased in rats.
In a prenatal/perinatal development study, pregnant rats received intravenous telavancin at up to 150 mg/kg/day (approximately the same AUC as observed at the maximum clinical dose) from the start of organogenesis through lactation. Offspring showed decreases in fetal body weight and an increase in the number of stillborn pups. Brachymelia was also observed. Developmental milestones and fertility of the pups were unaffected.
Nursing Mothers
It is not known whether telavancin is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when VIBATIV is administered to a nursing woman.
Pediatric Use
The safety and effectiveness of VIBATIV in pediatric patients has not been studied.
Geriatric Use
Of the 929 patients treated with VIBATIV at a dose of 10 mg/kg once daily in clinical trials of cSSSI, 174 (19%) were ≥65 years of age and 87 (9%) were ≥75 years of age. In the cSSSI trials, lower clinical cure rates were observed in patients ≥65 years of age compared with those <65 years of age. Overall, treatment-emergent adverse events occurred with similar frequencies in patients ≥65 (75% of patients) and <65 years of age (83% of patients). Fifteen of 174 (9%) patients ≥65 years of age treated with VIBATIV had adverse events indicative of renal impairment compared with 16 of 755 (2%) patients <65 years of age [see Warnings and Precautions (5.3), Clinical Trials (14.1)].
Of the 749 HABP/VABP patients treated with VIBATIV at a dose of 10 mg/kg once daily in clinical trials of HABP/VABP, 397 (53%) were ≥65 years of age and 230 (31%) were ≥75 years of age. Treatment-emergent adverse events as well as deaths and other serious adverse events occurred more often in patients ≥65 years of age than in those <65 years of age in both treatment groups.
Telavancin is substantially excreted by the kidney, and the risk of adverse reactions may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection in this age group.
The mean plasma AUC values of telavancin were similar in healthy young and elderly subjects. Dosage adjustment for elderly patients should be based on renal function [see Dosage and Administration (2), Clinical Pharmacology (12.3)].
Patients with Renal Impairment
The HABP/VABP and cSSSI trials included patients with normal renal function and patients with varying degrees of renal impairment. Patients with underlying renal dysfunction or risk factors for renal dysfunction had a higher incidence of renal adverse events [see Warnings and Precautions (5.3)].
In the HABP/VABP studies higher mortality rates were observed in the VIBATIV-treated patients with baseline CrCl≤50 mL/min. Use of VIBATIV in patients with pre-existing moderate/severe renal impairment should be considered only when the anticipated benefit to the patient outweighs the potential risk [see Warnings and Precautions (
5.1
)].
VIBATIV-treated patients in the cSSSI studies with baseline creatinine clearance ≤50 mL/min had lower clinical cure rates. Consider these data when selecting antibacterial therapy in patients with baseline moderate/severe renal impairment (CrCl ≤50 mL/min) [see Warnings and Precautions (5.2
)].
Dosage adjustment is required in patients with ≤50 mL/min renal impairment [see Dosage and Administration (2
)]. There is insufficient information to make specific dosage adjustment recommendations for patients with end-stage renal disease (CrCl <10 mL/min), including patients receiving hemodialysis [see Overdosage (10), Clinical Pharmacology (12.3)].
Hydroxypropyl-beta-cyclodextrin is excreted in urine and may accumulate in patients with renal impairment. Serum creatinine should be closely monitored and, if renal toxicity is suspected, an alternative agent should be considered [see Warnings and Precautions (5.3), Clinical Pharmacology (12.3)].
Patients with Hepatic Impairment
The HABP/VABP and cSSSI trials included patients with normal hepatic function and with hepatic impairment. No dosage adjustment is recommended in patients with mild or moderate hepatic impairment [see Clinical Pharmacology (12.3)].