Simnoxin Simnotrelvir Tablets/Ritonavir Tablets

1. Indications and Usage
COVID-19 Treatment: Treatment of mild to moderate coronavirus disease 2019 (COVID-19) in adult patients.
Timing Requirement: Should be used as soon as possible after the onset of symptoms, ideally within 3 days.
2. Dosage and Administration
Route of Administration: Oral administration ONLY.
Standard Dosage: 750 mg Simnotrelvir and 100 mg Ritonavir every 12 hours for 5 days.
Renal Impairment:
Mild (eGFR 60-89): No adjustment needed.
Moderate (eGFR 30-59): Reduce to 375 mg Simnotrelvir and 100 mg Ritonavir every 12 hours.
Severe (eGFR <30): Contraindicated.
Hepatic Impairment: No adjustment for mild or moderate impairment. Contraindicated in severe impairment.
Critical Administration Instructions:
Fasting: Administer on an empty stomach.
Swallowing: Tablets must be swallowed whole; do not chew, divide, or crush.
Co-administration: Simnotrelvir must be taken with Ritonavir to achieve therapeutic plasma levels.
3. Mechanism of Action
Mpro Inhibition: Simnotrelvir is a peptidomimetic inhibitor of the SARS-CoV-2 main protease (Mpro), preventing the processing of polyprotein precursors and stopping viral replication.
Metabolic Inhibition: Ritonavir inhibits CYP3A-mediated metabolism of Simnotrelvir, significantly increasing its plasma concentration and therapeutic efficacy.
4. Safety and Warnings
Pregnancy: Contraindicated during pregnancy. Effective contraception is required during and for 7 days after the final dose.
Hypersensitivity: Contraindicated in patients with known hypersensitivity to the active ingredients or excipients.
Drug Interactions: Strictly contraindicated with drugs highly dependent on CYP3A for clearance where concentration elevation causes severe harm, or with strong CYP3A inducers which may cause therapeutic failure.
5. Adverse Reactions and Clinical Research
Most Common Adverse Reactions: Neutrophil count decreased, dyslipidemia, diarrhea, nausea, pruritus, sinus bradycardia, and vomiting.
Clinical Research Highlights: In the Phase II/III SIM0417-301 trial, the combination demonstrated efficacy in treating symptomatic mild-to-moderate COVID-19 with a manageable safety profile.
6. Drug Interactions
Contraindicated CYP3A Substrates: Includes Alfuzosin, Pimozide, Quinidine, and others where increased plasma levels cause serious or life-threatening reactions.
Contraindicated CYP3A Inducers: Includes Carbamazepine, Phenobarbital, Phenytoin, and Rifampin, which significantly decrease drug exposure.
Moderate CYP3A Inhibitors: Drugs like Diltiazem or Verapamil may increase Simnotrelvir exposure and require clinical monitoring.
7. Pharmaceutical Information
Chemical Composition: Active Ingredients: Simnotrelvir and Ritonavir.
Appearance: Simnotrelvir tablets are pinkish-red oval film-coated tablets; Ritonavir tablets are white or off-white oval film-coated tablets.
Packaging: Co-packaged combination.
Storage: Store in the original packaging to protect from moisture and light.