Byfavo Drug Information
Generic name: REMIMAZOLAM BESYLATE
Uses of Byfavo
BYFAVO ® is indicated for the induction and maintenance of procedural sedation in adults undergoing procedures lasting 30 minutes or less.
Dosage & Administration of Byfavo
Important Dosage and Administration Instructions BYFAVO can depress respiration. Continuously monitor patients for early signs of hypoventilation, airway obstruction, and apnea using capnography, pulse oximetry, and clinical assessment. Only personnel trained in the administration of procedural sedation, and not involved in the conduct of the diagnostic or therapeutic procedure, should administer BYFAVO.
Administering personnel must be trained in the detection and management of airway obstruction, hypoventilation, and apnea, including the maintenance of a patent airway, supportive ventilation, and cardiovascular resuscitation. Supplemental oxygen, resuscitative drugs, and age- and size-appropriate equipment for bag/valve/mask assisted ventilation must be immediately available during administration of BYFAVO. A benzodiazepine reversal agent should be immediately available.
Continuously monitor vital signs during sedation and through the recovery period. Peak sedation occurs approximately 3 to 3.5 minutes after an initial 5 mg intravenous injection of BYFAVO given over a 1-minute period. Titrate subsequent doses of BYFAVO on the basis of clinical judgment and assessment of the depth of sedation.
If maintenance of procedural sedation is inadequate, consider alternative medications.
Basic Dosing Information Individualize
BYFAVO dosing and titrate to desired clinical response. In clinical studies, fentanyl 25 to 75 mcg was administered for analgesia prior to the first dose of BYFAVO. Supplemental doses of fentanyl were administered as needed for analgesia.
Recommended dosing guidelines:
Preparation Reconstitution of BYFAVO (remimazolam) for injection Strict aseptic technique must be maintained during handling of BYFAVO. This product does not contain preservative. Once removed from packaging, protect vials from light.
Each single-patient-use vial contains 20 mg BYFAVO lyophilized powder for reconstitution. The product must be prepared immediately before use. To reconstitute, add 8.2 mL sterile 0.9% Sodium Chloride Injection, USP, to the vial, directing the stream of solution toward the wall of the vial.
Gently swirl the vial (do not shake) until the contents are fully dissolved. The reconstituted product will deliver a final concentration of 2.5 mg/mL solution of BYFAVO. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration.
Upon reconstitution, the solution should be a clear, colorless to pale yellow solution. Discard if particulate matter or discoloration is observed. If not used immediately, reconstituted BYFAVO may be stored in the vial for up to 8 hours under controlled room temperature at 20°C to 25°C (68°F to 77°F).
BYFAVO has also been shown to be compatible with Ringer's Solution, a solution containing Sodium Chloride, Potassium Chloride and Calcium Chloride Dihydrate. Lactated Ringer's Solution is also known as Ringer's Lactate Solution, Compound Sodium Lactate Solution, and Hartmann's Solution. Acetated Ringer's Solution, a solution containing Sodium Chloride, Sodium Acetate, Potassium Chloride, and Calcium Chloride Dihydrate.
BYFAVO compatibility with other agents has not been adequately evaluated. Do not mix BYFAVO with other drugs or fluids prior to administration.
| Induction of Procedural Sedation | For adult patients: Administer 5 mg intravenously over a 1-minute time period. |
|---|---|
| For ASA ASA = American Society of Anesthesiologists Physical Status Classification System III and IV patients: Administer 2.5 mg to 5 mg intravenously over 1 minute based on the general condition of the patient. | |
| Maintenance of Procedural Sedation (as needed) | For adult patients: Administer 2.5 mg intravenously over 15 seconds. At least 2 minutes must elapse prior to administration of any supplemental dose. |
| For ASA III and IV patients: Administer 1.25 mg to 2.5 mg intravenously over 15 seconds. At least 2 minutes must elapse prior to administration of any supplemental dose. |
Side Effects of Byfavo
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The safety of BYFAVO was evaluated in three prospective, randomized, double-blind, multicenter, parallel group clinical studies in 630 patients undergoing colonoscopy (two studies) or bronchoscopy (one study). Colonoscopy Study 1 and the bronchoscopy study evaluated American Society of Anesthesiologists (ASA) physical status I to III patients, and Colonoscopy Study 2 evaluated ASA III and IV patients.
All three studies evaluated the safety of BYFAVO compared to placebo with midazolam rescue and an open-label midazolam treatment arm. Patients were administered a total dose ranging from 5 to 30 mg of BYFAVO. In these studies, the most common adverse reactions (incidence greater than 10%) following BYFAVO administration were hypotension, hypertension, diastolic hypertension, systolic hypertension, hypoxia, and diastolic hypotension.
There were two patients who experienced an adverse reaction that led to discontinuation of study drug. One patient in the BYFAVO arm in the bronchoscopy study discontinued treatment due to bradycardia, hypertension, hypotension, hypoxia, and respiratory rate increase. One patient in the open-label midazolam arm in Colonoscopy Study 2 discontinued due to respiratory acidosis.
No deaths were reported during the studies. Tables 1-3 provide a summary of the common adverse reactions observed in each of the three Phase 3 studies with BYFAVO. There were too few patients in each fentanyl stratum in Colonoscopy Study 2 to perform this analysis.
| Adverse Reaction | BYFAVO N = 296 | Placebo (with Midazolam Rescue 57/60 (95%) patients received midazolam rescue. ) N = 60 | Midazolam N = 102 |
|---|---|---|---|
| n (%) | n (%) | n (%) | |
| Hypotension Hypotension defined as a fall in systolic BP to ≤80 mmHg or in diastolic BP to ≤40 mmHg, or a fall in systolic or diastolic BP of 20% or more below baseline or necessitating medical intervention. | 115 (39%) | 25 (42%) | 63 (62%) |
| Hypertension Hypertension defined as an increase in systolic BP to ≥180 mmHg or in diastolic BP to ≥100 mmHg, or an increase of systolic or diastolic BP of 20% or more over baseline or necessitating medical intervention. | 59 (20%) | 17 (28%) | 18 (18%) |
| Bradycardia | 33 (11%) | 7 (12%) | 16 (16%) |
| Diastolic hypertension | 29 (10%) | 6 (10%) | 9 (9%) |
| Tachycardia | 23 (8%) | 7 (12%) | 13 (13%) |
| Diastolic hypotension | 23 (8%) | 4 (7%) | 9 (9%) |
| Systolic hypertension | 16 (5%) | 5 (8%) | 6 (6%) |
| Adverse Reaction | BYFAVO N = 303 | Placebo (with Midazolam Rescue 57/59 (97%) patients received midazolam rescue. ) N = 59 | Midazolam N = 69 |
|---|---|---|---|
| n (%) | n (%) | n (%) | |
| Hypotension Hypotension defined as a fall in systolic BP to ≤80 mmHg or in diastolic BP to ≤40 mmHg, or a fall in systolic or diastolic BP of 20% or more below baseline or necessitating medical intervention. | 99 (33%) | 28 (47%) | 23 (33%) |
| Hypertension Hypertension defined as an increase in systolic BP to ≥180 mmHg or in diastolic BP to ≥100 mmHg, or an increase of systolic or diastolic BP of 20% or more over baseline or necessitating medical intervention. | 85 (28%) | 9 (15%) | 19 (28%) |
| Diastolic hypertension | 77 (25%) | 15 (25%) | 16 (23%) |
| Systolic hypertension | 67 (22%) | 13 (22%) | 17 (25%) |
| Hypoxia | 66 (22%) | 12 (20%) | 13 (19%) |
| Respiratory rate increased | 43 (14%) | 6 (10%) | 10 (14%) |
| Diastolic hypotension | 41 (14%) | 17 (29%) | 16 (23%) |
| Nausea | 12 (4%) | 2 (3%) | 2 (3%) |
| Bradycardia | 11 (4%) | 4 (7%) | 4 (6%) |
| Pyrexia | 11 (4%) | 1 (2%) | 1 (1%) |
| Headache | 8 (3%) | 0 (0%) | 3 (4%) |
| Adverse Reaction | BYFAVO N = 31 | Placebo (with Midazolam Rescue 16/16 (100%) patients received midazolam rescue. ) N = 16 | Midazolam N = 30 |
|---|---|---|---|
| n (%) | n (%) | n (%) | |
| Hypotension Hypotension defined as a fall in systolic BP to ≤80 mmHg or in diastolic BP to ≤40 mmHg, or a fall in systolic or diastolic BP of 20% or more below baseline or necessitating medical intervention. | 18 (58%) | 11 (69%) | 17 (57%) |
| Hypertension Hypertension defined as an increase in systolic BP to ≥180 mmHg or in diastolic BP to ≥100 mmHg, or an increase of systolic or diastolic BP of 20% or more over baseline or necessitating medical intervention. | 13 (42%) | 6 (38%) | 13 (43%) |
| Respiratory acidosis | 6 (19%) | 2 (13%) | 8 (27%) |
| Diastolic hypertension | 3 (10%) | 0 (0%) | 0 (0%) |
| Systolic hypertension | 2 (6%) | 0 (0%) | 0 (0%) |
| Bradycardia | 1 (3%) | 1 (6%) | 4 (13%) |
| Respiratory rate decreased | 1 (3%) | 1 (6%) | 2 (7%) |
| Diastolic hypotension | 1 (3%) | 1 (6%) | 0 (0%) |
| Blood pressure diastolic increased | 1 (3%) | 0 (0%) | 0 (0%) |
| Blood pressure increased | 1 (3%) | 0 (0%) | 0 (0%) |
| Blood pressure systolic increased | 1 (3%) | 0 (0%) | 0 (0%) |
| Upper respiratory tract infection | 1 (3%) | 0 (0%) | 0 (0%) |
| BYFAVO | Placebo (with Midazolam Rescue 57/60 (95%) patients received midazolam rescue. ) | Midazolam | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Fentanyl dose (mcg) | <100 | 100-150 | >150 | <100 | 100-150 | >150 | <100 | 100-150 | >150 |
| N = 148 | N = 146 | N = 2 | N = 9 | N = 43 | N = 8 | N = 31 | N = 62 | N = 9 | |
| Adverse Reaction | n (%) | n (%) | n (%) | n (%) | n (%) | n (%) | n (%) | n (%) | n (%) |
| Hypotension Hypotension defined as a fall in systolic BP to ≤80 mmHg or in diastolic BP to ≤40 mmHg, or a fall in systolic or diastolic BP of 20% or more below baseline or necessitating medical intervention. | 49 (33%) | 64 (44%) | 2 (100%) | 5 (56%) | 17 (40%) | 3 (38%) | 18 (58%) | 36 (58%) | 9 (100%) |
| Hypertension Hypertension defined as an increase in systolic BP to ≥180 mmHg or in diastolic BP to ≥100 mmHg, or an increase of systolic or diastolic BP of 20% or more over baseline or necessitating medical intervention. | 24 (16%) | 35 (24%) | 0 (0%) | 1 (11%) | 14 (33%) | 2 (25%) | 3 (10%) | 12 (19%) | 3 (33%) |
| Bradycardia | 12 (8%) | 20 (14%) | 1 (50%) | 0 (0%) | 5 (12%) | 2 (25%) | 1 (3%) | 13 (21%) | 2 (22%) |
| Diastolic hypertension | 9 (6%) | 20 (14%) | 0 (0%) | 0 (0%) | 3 (7%) | 3 (38%) | 2 (6%) | 7 (11%) | 0 (0%) |
| Tachycardia | 10 (7%) | 12 (8%) | 1 (50%) | 0 (0%) | 6 (14%) | 1 (13%) | 2 (6%) | 8 (13%) | 3 (33%) |
| Diastolic hypotension | 10 (7%) | 13 (9%) | 0 (0%) | 0 (0%) | 3 (7%) | 1 (13%) | 3 (10%) | 4 (6%) | 2 (22%) |
| Systolic hypertension | 5 (3%) | 11 (8%) | 0 (0%) | 0 (0%) | 3 (7%) | 2 (25%) | 4 (13%) | 2 (3%) | 0 (0%) |
| BYFAVO | Placebo (with Midazolam Rescue 57/59 (97%) patients received midazolam rescue. ) | Midazolam | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Fentanyl dose (mcg) | <100 | 100-150 | >150 | <100 | 100-150 | >150 | <100 | 100-150 | >150 |
| N = 215 | N = 63 | N = 25 | N = 26 | N = 18 | N = 15 | N = 29 | N = 27 | N = 13 | |
| Adverse Reaction | n (%) | n (%) | n (%) | n (%) | n (%) | n (%) | n (%) | n (%) | n (%) |
| Hypotension Hypotension defined as a fall in systolic BP to ≤ 80 mmHg or in diastolic BP to ≤40 mmHg, or a fall in systolic or diastolic BP of 20% or more below baseline or necessitating medical intervention. | 52 (24%) | 32 (51%) | 16 (64%) | 7 (27%) | 9 (50%) | 12 (80%) | 7 (24%) | 7 (26%) | 9 (69%) |
| Hypertension Hypertension defined as an increase in systolic BP to ≥180 mmHg or in diastolic BP to ≥100 mmHg, or an increase of systolic or diastolic BP of 20% or more over baseline or necessitating medical intervention. | 43 (20%) | 25 (40%) | 18 (72%) | 2 (8%) | 2 (11%) | 5 (33%) | 3 (10%) | 8 (30%) | 8 (62%) |
| Diastolic hypertension | 65 (30%) | 12 (19%) | 0 (0%) | 11 (42%) | 3 (17%) | 1 (7%) | 10 (34%) | 6 (22%) | 0 (0%) |
| Systolic hypertension | 55 (26%) | 11 (17%) | 1 (4%) | 10 (38%) | 3 (17%) | 0 (0%) | 9 (31%) | 6 (22%) | 2 (15%) |
| Hypoxia | 35 (16%) | 22 (35%) | 9 (36%) | 6 (23%) | 2 (11%) | 4 (27%) | 2 (7%) | 5 (19%) | 6 (46%) |
| Respiratory rate increased | 22 (10%) | 12 (19%) | 9 (36%) | 1 (4%) | 2 (11%) | 3 (20%) | 2 (7%) | 5 (19%) | 3 (23%) |
| Diastolic hypotension | 28 (13%) | 13 (21%) | 0 (0%) | 8 (31%) | 7 (39%) | 2 (13%) | 7 (24%) | 6 (22%) | 3 (23%) |
| Nausea | 9 (4%) | 1 (2%) | 2 (8%) | 0 (0%) | 0 (0%) | 2 (13%) | 1 (3%) | 1 (4%) | 0 (0%) |
| Bradycardia | 3 (1%) | 4 (6%) | 4 (16%) | 2 (8%) | 1 (6%) | 1 (7%) | 0 (0%) | 2 (7%) | 2 (15%) |
| Pyrexia | 7 (3%) | 2 (3%) | 2 (8%) | 0 (0%) | 0 (0%) | 1 (7%) | 1 (3%) | 0 (0%) | 0 (0%) |
| Headache | 5 (2%) | 2 (3%) | 1 (4%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 3 (11%) | 0 (0)% |
Warnings & Cautions for Byfavo
Personnel and Equipment for Monitoring and Resuscitation
Clinically notable hypoxia, bradycardia, and hypotension were observed in Phase 3 studies of BYFAVO. Continuously monitor vital signs during sedation and through the recovery period. Only personnel trained in the administration of procedural sedation, and not involved in the conduct of the diagnostic or therapeutic procedure, should administer BYFAVO.
Administering personnel must be trained in the detection and management of airway obstruction, hypoventilation, and apnea, including the maintenance of a patent airway, supportive ventilation, and cardiovascular resuscitation. Resuscitative drugs, and age- and size-appropriate equipment for bag/valve/mask assisted ventilation must be immediately available during administration of BYFAVO. Consider the potential for worsened cardiorespiratory depression prior to using BYFAVO concomitantly with other drugs that have the same potential (e.g., opioid analgesics or other sedative-hypnotics).
Administer supplemental oxygen to sedated patients through the recovery period. A benzodiazepine reversal agent (flumazenil) should be immediately available during administration of BYFAVO.
Risks from Concomitant Use with Opioid Analgesics and Other Sedative-Hypnotics Concomitant use of benzodiazepines, including BYFAVO, and opioid analgesics may result in profound sedation, respiratory depression, coma, and death. The sedative effect of intravenous BYFAVO can be accentuated by concomitantly administered CNS depressant medications, including other benzodiazepines and propofol. Titrate the dose of BYFAVO when administered with opioid analgesics and sedative-hypnotics to the desired clinical response.
Continuously monitor sedated patients for hypotension, airway obstruction, hypoventilation, apnea, and oxygen desaturation. These cardiorespiratory effects may be more likely to occur in patients with obstructive sleep apnea, the elderly, and ASA III or IV patients.
Hypersensitivity Reactions
BYFAVO contains dextran 40, which can cause hypersensitivity reactions, including rash, urticaria, pruritus, and anaphylaxis. BYFAVO is contraindicated in patients with a history of severe hypersensitivity reaction to dextran 40 or products containing dextran 40.
Neonatal Sedation and Withdrawal Syndrome
Receiving benzodiazepines late in pregnancy can result in sedation (respiratory depression, lethargy, hypotonia) and/or withdrawal symptoms (hyperreflexia, irritability, restlessness, tremors, inconsolable crying, and feeding difficulties) in the neonate. Monitor neonates exposed to benzodiazepines, including BYFAVO, during pregnancy or labor for signs of sedation and monitor neonates exposed to benzodiazepines during pregnancy for signs of withdrawal and manage these neonates accordingly.
Pediatric Neurotoxicity
Published animal studies demonstrate that the administration of anesthetic and sedation drugs that block NMDA receptors and/or potentiate GABA activity increase neuronal apoptosis in the developing brain and result in long-term cognitive deficits when used for longer than 3 hours. The clinical significance of these findings is not clear. However, based on the available data, the window of vulnerability to these changes is believed to correlate with exposures in the third trimester of gestation through the first several months of life, but may extend out to approximately three years of age in humans.
Some published studies in children suggest that similar deficits may occur after repeated or prolonged exposures to anesthetic agents early in life and may result in adverse cognitive or behavioral effects. These studies have substantial limitations, and it is not clear if the observed effects are due to the anesthetic/sedation drug administration or other factors such as the surgery or underlying illness. Anesthetic and sedation drugs are a necessary part of the care of children needing surgery, other procedures, or tests that cannot be delayed, and no specific medications have been shown to be safer than any other.
Decisions regarding the timing of any elective procedures requiring anesthesia should take into consideration the benefits of the procedure weighed against the potential risks.
Drug Interactions with Byfavo
Opioid Analgesics and Other Sedative-Hypnotics
The sedative effect of intravenous BYFAVO can be accentuated by concomitantly administered CNS depressant medications, including opioid analgesics, other benzodiazepines, and propofol. Continuously monitor vital signs during sedation and through the recovery period. Titrate the dose of BYFAVO when administered with opioid analgesics and sedative-hypnotics to the desired clinical response.
Pregnancy Safety for Byfavo
Pregnancy Risk Summary Neonates born to mothers using benzodiazepines late in pregnancy have been reported to experience symptoms of sedation and/or neonatal withdrawal. Available data from published observational studies of pregnant women exposed to benzodiazepines do not report a clear association with benzodiazepines and major birth defects (see Data ). In animal studies, reduced fetal weights but no evidence of malformations or embryofetal lethality were noted in a study in which pregnant rabbits were treated intravenously with 4 times the maximum recommended human dose (MRHD) of 30 mg during organogenesis.
Adequate rodent reproductive and developmental toxicology studies have not been completed to fully evaluate the effects of BYFAVO. Published studies in pregnant primates demonstrate that the administration of anesthetic and sedation drugs that block NMDA receptors and/or potentiate GABA activity during the period of peak brain development increases neuronal apoptosis in the developing brain of the offspring when used for longer than 3 hours. There are no data on pregnancy exposures in primates corresponding to periods prior to the third trimester in humans (see Data ).
The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is respectively.
Clinical Considerations Fetal/Neonatal Adverse Reactions Benzodiazepines cross the placenta and may produce respiratory depression, hypotonia, and sedation in neonates. Monitor neonates exposed to BYFAVO during pregnancy or labor for signs of sedation, respiratory depression, hypotonia, and feeding problems. Manage these neonates accordingly.
Data Human Data Published data from observational studies on the use of benzodiazepines during pregnancy do not report a clear association with benzodiazepines and major birth defects. Although early studies reported an increased risk of congenital malformations with diazepam and chlordiazepoxide, there was no consistent pattern noted. In addition, the majority of more recent case-control and cohort studies of benzodiazepine use during pregnancy, which were adjusted for confounding exposures to alcohol, tobacco, and other medications, have not confirmed these findings.
Animal Data Reduced fetal weights but no evidence of malformation or embryofetal lethality were noted in a study in which pregnant rabbits were treated intravenously with 5 mg/kg remimazolam (approximately 4 times the MRHD of 30 mg/day based on AUC) from Gestation Day 6 to 20 in the presence of maternal toxicity (reduced food intake and body weights). In a study that did not test exposures comparable to the MRHD of 30 mg/day over the full period of organogenesis, there was an increase in early resorptions (embryolethality) but no evidence of malformations when female rats were treated from Gestation Day 6 through 17 with up to 30 mg/kg remimazolam via intravenous bolus (approximately 0.3 times the MRHD based on AUC by the end of the dosing interval) in the presence of maternal toxicity (convulsion in one mid dose and one high dose dam). In a pre- and postnatal development study that did not test exposures comparable to the MRHD of 30 mg/day over the full treatment period, there were no adverse effects on survival or development of offspring when pregnant rats were treated with up to 30 mg/kg remimazolam (<0.3 times the MRHD by the end of the gestational period) by intravenous bolus injection from Gestation Day 6 through Lactation Day 20 with minimal evidence of maternal toxicity (sedation).
No evidence of adverse effects on physical development, a functional observational battery of behavioral assessments, or fertility were noted in pups born to pregnant rabbits that were treated by intravenous infusion of up to 20 mg/kg/day remimazolam (approximately 19 times the MRHD based on AUC) from 14 days prior to mating until Lactation Day 30 despite the presence of maternal toxicity (sedation, convulsions, and mortality). Learning and memory of the first-generation offspring was not evaluated in this study. In a published study in primates, administration of an anesthetic dose of ketamine for 24 hours on Gestation Day 122 increased neuronal apoptosis in the developing brain of the fetus.
In other published studies, administration of either isoflurane or propofol for 5 hours on Gestation Day 120 resulted in increased neuronal and oligodendrocyte apoptosis in the developing brain of the offspring. With respect to brain development, this time period corresponds to the third trimester of gestation in the human. The clinical significance of these findings is not clear; however, studies in juvenile animals suggest neuroapoptosis correlates with long-term cognitive deficits.
Pediatric Use of Byfavo
Pediatric Use Safety and effectiveness in pediatric patients have not been established. No studies are available in any pediatric population and extrapolation of adult effectiveness data to the pediatric population is not possible. Published juvenile animal studies demonstrate that the administration of anesthetic and sedation drugs, such as BYFAVO, that either block NMDA receptors or potentiate the activity of GABA during the period of rapid brain growth or synaptogenesis, results in widespread neuronal and oligodendrocyte cell loss in the developing brain and alterations in synaptic morphology and neurogenesis.
Based on comparisons across species, the window of vulnerability to these changes is believed to correlate with exposures in the third trimester of gestation through the first several months of life but may extend out to approximately 3 years of age in humans. In primates, exposure to 3 hours of ketamine that produced a light surgical plane of anesthesia did not increase neuronal cell loss; however, treatment regimens of 5 hours or longer of isoflurane increased neuronal cell loss. Data from isoflurane-treated rodents and ketamine-treated primates suggest that the neuronal and oligodendrocyte cell losses are associated with prolonged cognitive deficits in learning and memory.
The clinical significance of these nonclinical findings is not known, and healthcare providers should balance the benefits of appropriate anesthesia in pregnant women, neonates, and young children who require procedures with the potential risks suggested by the nonclinical data.
Contraindications for Byfavo
BYFAVO is contraindicated in patients with a history of severe hypersensitivity reaction to dextran 40 or products containing dextran 40. Hypersensitivity to dextran 40.
Overdosage Information for Byfavo
Clinical Presentation Overdosage of benzodiazepines is characterized by central nervous system depression ranging from drowsiness to coma. In mild to moderate cases, symptoms can include drowsiness, confusion, dysarthria, lethargy, hypnotic state, diminished reflexes, ataxia, and hypotonia. Rarely, paradoxical or disinhibitory reactions (including agitation, irritability, impulsivity, violent behavior, confusion, restlessness, excitement, and talkativeness) may occur.
In severe overdosage cases, patients may develop respiratory depression and coma. Overdosage of benzodiazepines in combination with other CNS depressants (including alcohol and opioids) may be fatal. Markedly abnormal (lowered or elevated) blood pressure, heart rate, or respiratory rate raise the concern that additional drugs and/or alcohol are involved in the overdosage.
Management of Overdosage In managing benzodiazepine overdosage, employ general supportive measures, including intravenous fluids and airway management. Flumazenil, a specific benzodiazepine receptor antagonist indicated for the complete or partial reversal of the sedative effects of benzodiazepines in the management of benzodiazepine overdosage, can lead to withdrawal and adverse reactions, including seizures, particularly in the context of mixed overdosage with drugs that increase seizure risk (e.g., tricyclic and tetracyclic antidepressants) and in patients with long-term benzodiazepine use and physical dependency. The risk of withdrawal seizures with flumazenil use may be increased in patients with epilepsy.
Flumazenil is contraindicated in patients who have received a benzodiazepine for control of a potentially life-threatening condition (e.g., status epilepticus). If the decision is made to use flumazenil, it should be used as an adjunct to, not as a substitute for, supportive management of benzodiazepine overdosage. See the flumazenil injection Prescribing Information.
Consider contacting the Poison Help Line (1-800-222-1222), or medical toxicologist for additional overdosage management recommendations.
Clinical Studies of Byfavo
Colonoscopy Study 1 (NCT 02290873) This Phase 3 study was conducted in 461 ASA I to III patients undergoing colonoscopy. Midazolam rescue was dosed per investigator discretion in both treatment groups. Fentanyl was administered as an analgesic pre-treatment at an initial dose of 50 to 75 mcg IV (or a reduced dose for ASA III patients) immediately prior to administration of the initial dose of study medication.
Supplemental oxygen was administered prior to the start of the procedure and continued at a rate of 1 to 5 L/minute until the patient was fully alert after procedure completion. Colonoscopy started when adequate sedation was achieved, defined as an MOAA/S score ≤3. The primary efficacy endpoint for BYFAVO versus placebo was success of the colonoscopy procedure, defined as a composite of the following: Completion of the colonoscopy procedure, AND No requirement for a rescue sedative medication, AND No requirement for more than 5 doses of study medication within any 15-minute window.
There were 143 patients in ASA I, 285 in ASA II, and 30 in ASA III. As shown in Table 6, the colonoscopy sedation success rate was statistically significantly higher in the BYFAVO group than in the placebo group. Table 6.
Colonoscopy Sedation Success Rate – Colonoscopy Study 1 The reasons for procedural sedation failure are shown in Table 7. Table 7. Reasons for Procedural Sedation Failure – Colonoscopy Study 1 Table 8 shows the number of top-up doses required, and the total doses of study medication, fentanyl, and rescue medication administered.
Table 8. Number of Top-up Doses and Total Doses of Study Medication, Fentanyl, and Rescue Medication – Colonoscopy Study 1 Summaries of the time to start procedure, duration of procedure, time to fully alert, and time to ready for discharge are shown in Table 9. Table 9.
Bronchoscopy Study (NCT 02296892) This Phase 3 study was conducted in 431 ASA I to III patients undergoing bronchoscopy. Top-up doses of fentanyl 25 mcg every 5 to 10 minutes were allowed until analgesia was adequate. A maximum dose of fentanyl 200 mcg was recommended.
There were 15 patients in ASA I, 254 in ASA II, and 162 in ASA III. As shown in Table 10, the bronchoscopy sedation success rate was statistically significantly higher for the BYFAVO group than for the placebo group. Table 10.
Bronchoscopy Success Rates The reasons for procedural sedation failure are shown in Table 11. Table 11. Table 12.
Table 13. Fentanyl was administered as an analgesic pre-treatment at an initial maximum dose of 50 mcg (with dose reduction for debilitated patients), immediately prior to administration of the initial dose of study medication. The primary objective of the study was to assess the safety of multiple doses of BYFAVO compared to placebo and midazolam.
The total patient population, including all randomized patients who received any amount of study medication, comprised 31 patients in the remimazolam group, 16 patients in the placebo group, and 30 patients in the midazolam group. There were two patients, one each in the remimazolam and midazolam treatment groups, who were randomized, but did not receive a dose of study medication. There were 40 patients in ASA III and 37 patients in ASA IV.
In the remimazolam group, 90.3% of patients did not receive any rescue sedative medication, compared to 0.0% in the placebo group. There were no serious adverse reactions and no discontinuations due to adverse reactions observed in the remimazolam group. The incidence of hypotension (SMQ) was 61.3% in the remimazolam group and 75% in the placebo group.
No inferential statistical tests were performed in this trial. Patients who received BYFAVO for sedation during scheduled colonoscopy responded at a numerically greater rate than patients who received placebo (randomized analysis population – remimazolam: 27/32; placebo: 0/16 ).
| Cohort | Sedation Success Rate n/N (%) |
|---|---|
| n/N = number of successes/number of subjects in group. | |
| Remimazolam | 272/298 (91.3%) |
| Placebo | 1/60 (1.7%) |
| Reason | Remimazolam N = 298 n (%) | Placebo N = 60 n (%) |
|---|---|---|
| Rescue sedative medication taken | 10 (3.4%) | 57 (95%) |
| Too many doses within the predefined time window | 18 (6.0%) | 44 (73.3%) |
| Procedure not completed | 7 (2.3%) | 1 (1.7%) |
| Number of Top-up Doses of Study Drug (Mean ± SD) | Total Amount of Study Drug (mg) (Mean ± SD) | Total Amount of Fentanyl (mcg) (Mean ± SD) | Total Amount of Midazolam Rescue Medication (mg) (Mean ± SD) | |
|---|---|---|---|---|
| Remimazolam | 2.2 ± 1.6 | 10.5 ± 4.0 | 88.9 ± 21.7 | 0.3 ± 2.1 |
| Placebo | 5.1 ± 0.5 | 0 | 121.3 ± 34.4 | 6.8 ± 4.2 |
| Time to start procedure (minutes) Patients who were unable to start the procedure were excluded. | |
| Median (95% confidence interval) | 4.0 (4.0, 4.0) |
| Min, Max | 0, 26 |
| Duration of procedure (minutes) Patients who did not successfully complete the procedure were excluded. | |
| Median (95% confidence interval) | 12.0 (11.0, 13.0) |
| Min, Max | 3, 33 |
| Number (proportion) of procedures lasting longer than 30 minutes | 1/291 (0.3%) |
| Time to fully alert after end of colonoscopy (minutes) | |
| Median (95% confidence interval) | 6.0 (5.0, 7.0) |
| Min, Max | 0, 44 |
| Time to ready to discharge after end of colonoscopy (minutes) | |
| Median (95% confidence interval) | 44.0 (42.0, 46.0) |
| Min, Max | 3, 79 |
| Cohort | Total Success Rate n/N (%) |
|---|---|
| n/N = number of successes/number of subjects in group. | |
| Remimazolam | 250/310 (80.6%) |
| Placebo | 3/63 (4.8%) |
| Reason | Remimazolam N = 310 n (%) | Placebo N = 63 n (%) |
|---|---|---|
| Rescue sedative medication taken | 49 (15.8%) | 57 (90.5%) |
| Too many doses within the predefined time window | 14 (4.5%) | 10 (15.9%) |
| Procedure not completed | 9 (2.9%) | 3 (4.8%) |
| Number of Top-up Doses of Study Drug (Mean ± SD) | Total Amount of Study Drug (mg) (Mean ± SD) | Total Amount of Fentanyl (mcg) (Mean ± SD) | Total Amount of Midazolam Rescue Medication (mg) (Mean ± SD) | |
|---|---|---|---|---|
| Remimazolam | 2.6 ± 2.0 | 11.5 ± 5.1 | 81.8 ± 54.3 | 1.3 ± 3.5 |
| Placebo | 4.1 ± 0.8 | 0 | 118.8 ± 79.1 | 5.9 ± 3.7 |
| Time to start procedure (minutes) Patients who were unable to start the procedure were excluded. | |
| Median (95% confidence interval) | 4.1 (4.0, 4.8) |
| Min, Max | 1,41 |
| Duration of procedure (minutes) Patients who did not successfully complete the procedure were excluded. | |
| Median (95% confidence interval) | 10.0 (8.0, 11.0) |
| Min, Max | 1, 68 |
| Number (proportion) of procedures lasting longer than 30 minutes | 28/299 (9.4%) |
| Time to fully alert after end of bronchoscopy (minutes) | |
| Median (95% confidence interval) | 6.0 (5.2, 7.1) |
| Min, Max | 1.1, 107 |
| Time to ready to discharge after end of bronchoscopy (minutes) | |
| Median (95% confidence interval) | 60.0 (57.0, 63.0) |
| Min, Max | 6.6, 284 |
Drug information sourced from the FDA. This content is for informational purposes only and does not constitute medical advice. Consult a healthcare professional before making any medication decisions.
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