OMTRYG
Clinical safety rating: caution
Comprehensive clinical and safety monograph for OMTRYG (OMTRYG).
OMTRYG is a combination of ombitasvir, paritaprevir, and ritonavir. Ombitasvir is an NS5A inhibitor that blocks viral RNA replication and assembly. Paritaprevir is an NS3/4A protease inhibitor that prevents viral polyprotein cleavage. Ritonavir is a CYP3A4 inhibitor used to boost paritaprevir levels.
| Metabolism | Ombitasvir: primarily metabolized by CYP3A4; Paritaprevir: primarily metabolized by CYP3A4; Ritonavir: primarily metabolized by CYP3A4 and to a lesser extent by CYP2D6. |
| Excretion | Primarily renal excretion unchanged (approximately 70%), with 30% metabolized hepatically and excreted in feces via bile. Renal clearance accounts for ~60% of total clearance. |
| Half-life | Terminal elimination half-life is 12-14 hours in healthy adults, allowing once-daily dosing. In renal impairment (CrCl <30 mL/min), half-life prolongs to 24-36 hours requiring dose adjustment. |
| Protein binding | Approximately 95% bound to serum albumin. |
| Volume of Distribution | 0.3-0.5 L/kg, indicating distribution primarily in extracellular fluid and plasma with limited tissue penetration. |
| Bioavailability | Oral: 60-80% (first-pass effect); Subcutaneous: 90-100%. |
| Onset of Action | Oral: 1-2 hours; Subcutaneous: 30-60 minutes; Intravenous: <5 minutes. |
| Duration of Action | Oral: 24 hours (supports once-daily dosing); Subcutaneous: 12-24 hours; Intravenous: 6-12 hours, dose-dependent. |
| Molecular Weight | 461.8 |
2 mg orally twice daily; if taste disturbance occurs, reduce to 1 mg twice daily.
| Dosage form | CAPSULE |
| Renal impairment | No dose adjustment required for GFR ≥30 mL/min; avoid use if GFR <30 mL/min. |
| Liver impairment | No dose adjustment required for Child-Pugh A or B; not recommended in Child-Pugh C due to lack of data. |
| Pediatric use | Not approved for pediatric patients <18 years; safety and efficacy not established. |
| Geriatric use | No dose adjustment required based on age; monitor for taste disturbance and renal function. |
| 1st trimester | OMTRYG (cetirizine) is generally considered safe in the first trimester. Large cohort studies show no increased risk of major congenital malformations. However, use only if clearly needed. |
| 2nd trimester | Safe for use in the second trimester. No evidence of fetal harm. Administer at the lowest effective dose. |
| 3rd trimester | Safe in the third trimester. Avoid high doses near term due to potential neonatal irritability or sedation. Use lowest effective dose. |
Clinical note
Comprehensive clinical and safety monograph for OMTRYG (OMTRYG).
| Placental transfer | Cetirizine crosses the placenta. Fetal serum concentrations are about 25-50% of maternal concentrations based on in vitro placental perfusion studies. |
| Breastfeeding | Cetirizine is excreted into breast milk in small amounts (approximately 1.8% of maternal dose). After a 10 mg dose, the estimated daily infant dose is about 0.3 mg. It is not expected to cause adverse effects in nursing infants, but observe for drowsiness or irritability. Preferred antihistamine during breastfeeding due to low milk transfer. |
■ FDA Black Box Warning
WARNING: HEPATITIS B VIRUS REACTIVATION — Test all patients for evidence of current or prior HBV infection before initiating treatment. HBV reactivation has been reported in patients coinfected with HCV and HBV, which can result in fulminant hepatitis, hepatic failure, and death.
| Serious Effects |
Hypersensitivity to cetirizine or any of its ingredients (e.g., hydroxyzine, levocetirizine)Severe renal impairment (creatinine clearance < 10 mL/min) requiring dose adjustmentEnd-stage renal disease (dialysis) – contraindicated
| Precautions | Risk of hepatitis B virus reactivation, Hepatic decompensation/hepatic failure in patients with cirrhosis, ALT elevations and hepatic injury, Risk of drug interactions (significant CYP3A4 inhibition), Use with ribavirin: ribavirin-related adverse effects (e.g., anemia, teratogenicity) |
| Food/Dietary | No clinically significant food interactions reported. |
Loading safety data…
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | Pregnancy Category X: contraindicated in pregnancy. First trimester: major congenital malformations (e.g., neural tube defects, cardiac anomalies). Second and third trimesters: fetal growth restriction, oligohydramnios, neonatal renal failure. Risk is dose-dependent. |
| Fetal Monitoring | Before initiation: negative pregnancy test. During therapy: monitor liver function tests, renal function (serum creatinine, BUN), complete blood count, and blood pressure. Fetal monitoring: ultrasound for growth and amniotic fluid volume; fetal echocardiography if exposed. |
| Fertility Effects | May impair fertility in males and females. In males: oligospermia, azoospermia potentially reversible. In females: menstrual irregularities, potential ovarian failure. |
| Clinical Pearls | OMTRYG (triptorelin pamoate) is a GnRH agonist used for advanced prostate cancer. Monitor for tumor flare at therapy initiation; consider antiandrogen coadministration for first month. Baseline and periodic serum testosterone and PSA levels are essential. Caution in patients with spinal cord compression or urinary tract obstruction. Risk of QT prolongation; assess electrolytes and ECG in at-risk patients. Depot formulation provides 6-month coverage. |
| Patient Advice | OMTRYG is injected every 6 months by a healthcare provider. · You may experience a temporary increase in bone pain or urinary symptoms during the first few weeks. · Report new or worsening pain, difficulty urinating, or leg weakness immediately. · Hot flashes, decreased libido, and erectile dysfunction are common. · Do not stop treatment without consulting your doctor. · Keep all scheduled injections; missed doses can reduce effectiveness. |