Dosing Journavx
The recommended starting dose of Journavx is 100 mg orally on an empty stomach (at least 1 hour before or 2 hours after food), followed by 50 mg every 12 hours starting 12 hours after the initial dose, with subsequent doses taken with or without food. 1
Standard Dosing Regimen
Initial dose (Dose 1): 100 mg orally on an empty stomach at least 1 hour before or 2 hours after food to avoid delayed onset of action 1
- Clear liquids may be consumed during this fasting period (water, apple juice, vegetable broth, tea, black coffee) 1
Maintenance dosing (starting 12 hours after initial dose): 50 mg orally every 12 hours 1
- These doses may be taken with or without food 1
Duration: Use for the shortest duration consistent with treatment goals; has not been studied beyond 14 days 1
Grapefruit restriction: Avoid food or drink containing grapefruit during treatment 1
Administration: Swallow tablets whole; do not chew or crush 1
Dosing Modifications for Hepatic Impairment
Severe hepatic impairment (Child-Pugh Class C):
- Avoid use entirely 1
Moderate hepatic impairment (Child-Pugh Class B):
- Dose 1: 100 mg orally on empty stomach (same as standard) 1
- Doses 2-4: 50 mg every 12 hours (same as standard) 1
- Dose 5 and beyond: Reduce to 50 mg every 24 hours (instead of every 12 hours) 1
Mild hepatic impairment (Child-Pugh Class A):
- Use standard dosing regimen 1
Dosing with CYP3A Inhibitors
Strong CYP3A inhibitors:
- Journavx is contraindicated with strong CYP3A inhibitors 1
Moderate CYP3A inhibitors:
- Dose 1: 100 mg orally on empty stomach (same as standard) 1
- Doses 2-4: 50 mg every 12 hours (same as standard) 1
- Dose 5 and beyond: Reduce to 50 mg every 24 hours 1
- Continue avoiding grapefruit products 1
Key Clinical Considerations
Common pitfall: The initial dose requires fasting conditions while subsequent doses do not—this asymmetry in food requirements is critical for optimal efficacy, as food delays onset of action for the first dose but does not significantly affect subsequent doses 1
Practical timing example: If the first dose is taken at 8 AM on an empty stomach, the second dose should be taken at 8 PM (with or without food), then continue every 12 hours thereafter at 8 AM and 8 PM 1
Dose reduction triggers: Only two scenarios require dose reduction from every 12 hours to every 24 hours after the first four doses: moderate hepatic impairment or concomitant moderate CYP3A inhibitor use 1