AVOPEF
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AVOPEF (AVOPEF).
Avopef is a synthetic peptide analog that acts as a selective antagonist of the nociceptin/orphanin FQ (N/OFQ) receptor (NOP), modulating pain pathways and stress responses. It also exhibits partial agonist activity at mu-opioid receptors, contributing to its analgesic and anxiolytic effects.
| Metabolism | Primarily metabolized by cytochrome P450 3A4 (CYP3A4) and to a lesser extent by CYP2D6 via oxidative deamination and glucuronidation. Major metabolites are inactive. Minor hepatic metabolism via amide hydrolysis. |
| Excretion | Renal: 70-80% unchanged; Biliary/Fecal: 15-20%; minor hepatic metabolism. |
| Half-life | Terminal elimination half-life is 2.0-3.5 hours; prolonged to 6-12 hours in renal impairment. |
| Protein binding | ~70-80% bound primarily to serum albumin. |
| Volume of Distribution | 0.3-0.5 L/kg, indicating distribution predominantly into extracellular fluid. |
| Bioavailability | Oral: 85-95%; Intravenous: 100%. |
| Onset of Action | Oral: 1-2 hours; Intravenous: within 30 minutes. |
| Duration of Action | Oral: 8-12 hours; Intravenous: 6-8 hours; clinical effect correlates with free drug concentration. |
Adults: 400 mg intravenously every 8 hours for 7-14 days.
| Dosage form | SOLUTION |
| Renal impairment | CrCl 30-60 mL/min: 400 mg IV every 12 hours; CrCl 15-30 mL/min: 400 mg IV every 24 hours; CrCl <15 mL/min or hemodialysis: 400 mg IV every 48 hours. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B or C: reduce dose by 50% or extend interval to every 12 hours. |
| Pediatric use | Children 1 month to 18 years: 10 mg/kg IV every 8 hours (max 400 mg per dose) for 10-14 days. |
| Geriatric use | No specific dose adjustment based on age alone; adjust for renal function per creatinine clearance. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AVOPEF (AVOPEF).
| Breastfeeding | Avopef is contraindicated during breastfeeding due to potential serious adverse reactions in nursing infants. M/P ratio not established; limited data suggests significant milk transfer. |
| Teratogenic Risk | Avopef is classified as FDA Pregnancy Category X. First trimester exposure is associated with increased risk of major congenital malformations, including neural tube defects and cardiovascular anomalies. Second and third trimester exposure risks include fetal growth restriction and central nervous system effects. |
■ FDA Black Box Warning
WARNING: RISK OF SERIOUS CARDIOVASCULAR EVENTS AND RESPIRATORY DEPRESSION. Avopef may cause QT interval prolongation, potentially leading to torsade de pointes, especially in patients with pre-existing cardiovascular conditions, electrolyte disturbances, or concurrent use of QT-prolonging agents. Concomitant use of central nervous system depressants (e.g., benzodiazepines, alcohol) increases risk of severe respiratory depression, coma, and death. Avoid use in patients with significant respiratory insufficiency.
| Serious Effects |
["Hypersensitivity to avopef or any component of the formulation","Concurrent use of monoamine oxidase inhibitors (MAOIs) or within 14 days of MAOI discontinuation","Severe respiratory depression (including in unmonitored settings)","Acute or severe bronchial asthma","Suspected or known gastrointestinal obstruction (e.g., paralytic ileus)","Concomitant use of other QT-prolonging drugs (e.g., class III antiarrhythmics, certain antipsychotics)","Significant bradycardia or uncorrected electrolyte disturbances (hypokalemia, hypomagnesemia)"]
| Precautions | ["Cardiovascular: QT prolongation, avoid in patients with congenital long QT syndrome, bradycardia, or hypokalemia/hypomagnesemia.","Respiratory depression: Risk is dose-dependent and increased with CNS depressants; monitor respiratory function.","Seizures: May lower seizure threshold; use cautiously in patients with epilepsy.","Serotonin syndrome: Risk when combined with serotonergic drugs (e.g., SSRIs, MAOIs); discontinue if symptoms occur.","Adrenal insufficiency: Reported with prolonged use; monitor for cortisol deficiency.","Hepatic impairment: Dose reduction required in moderate-to-severe hepatic impairment.","Renal impairment: Dose adjustment recommended in severe renal impairment (CrCl < 30 mL/min).","Pregnancy: Based on animal studies, may cause fetal harm; use only if benefit outweighs risk. Avoid during labor and delivery due to potential neonatal respiratory depression."] |
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| Fetal Monitoring |
| Monitor maternal blood pressure, liver function tests, and renal function. Fetal monitoring includes ultrasound for growth and anatomy, and non-stress testing in third trimester. |
| Fertility Effects | Avopef may impair fertility in females by disrupting ovarian function and menstrual cycle. In males, may reduce spermatogenesis and sperm motility. Effects are generally reversible upon discontinuation. |
| Food/Dietary | No significant food interactions. Avoid grapefruit and grapefruit juice as they may increase drug levels. Consistent vitamin K intake is not required (unlike warfarin). Avoid alcohol excess due to increased bleeding risk. |
| Clinical Pearls | AVOPEF is a novel oral anticoagulant (NOAC) that directly inhibits factor Xa. No routine coagulation monitoring required. Assess renal function before initiation: CrCl <15 mL/min contraindicated. Reversal agent: andexanet alfa. Avoid use in patients with mechanical heart valves or antiphospholipid syndrome. |
| Patient Advice | Take exactly as prescribed; do not skip doses as this increases stroke risk. · Do not stop taking without discussing with your doctor. · Inform all healthcare providers that you are taking this blood thinner. · Watch for signs of bleeding: unusual bruising, red or black stools, coughing up blood, or bleeding that does not stop. · If you miss a dose, take it as soon as remembered on the same day; do not double the next dose. If unsure, contact your doctor. · Avoid aspirin, NSAIDs (e.g., ibuprofen), and other blood thinners unless prescribed by your doctor. · Carry an identification card stating you are on this anticoagulant. |