When should Journavax (suzetrigine) be administered relative to anesthesia, and what are the recommended dosing, timing, and contraindications for postoperative use?

Journavax (Suzetrigine) Administration Relative to Anesthesia

Initiate Journavax postoperatively as soon as the patient can tolerate oral medications, starting with 100 mg on an empty stomach, followed by 50 mg every 12 hours beginning 12 hours after the initial dose. 1

Timing of Administration

Postoperative Initiation

• Start Journavax after surgery when the patient can swallow tablets whole (do not crush or chew)
• The first dose (100 mg) must be taken on an empty stomach (at least 1 hour before or 2 hours after food) to avoid delayed onset of action
• Clear liquids are permitted during this fasting period (water, apple juice, vegetable broth, tea, black coffee)
• Expect perceptible pain relief to begin at approximately 60 minutes, with peak effect at 240 minutes 2

Maintenance Dosing

• 12 hours after the initial dose, begin 50 mg every 12 hours
• These maintenance doses can be taken with or without food
• Continue for the shortest duration consistent with pain control goals
• Maximum studied duration is 14 days 1

Critical Contraindications and Drug Interactions

Absolute Contraindications

• Strong CYP3A inhibitors (e.g., ketoconazole, clarithromycin, ritonavir) - this is a hard contraindication 1

Required Dose Adjustments

Moderate CYP3A Inhibitors:

• Initial dose: 100 mg (same as standard)
• Doses 2-4: 50 mg every 12 hours
• Dose 5 and beyond: reduce to 50 mg every 24 hours (not every 12 hours) 1

Moderate Hepatic Impairment (Child-Pugh B):

• Same dosing adjustment as moderate CYP3A inhibitors above
• Initial dose: 100 mg
• Doses 2-4: 50 mg every 12 hours
• Dose 5 and beyond: 50 mg every 24 hours 1

Severe Hepatic Impairment (Child-Pugh C):

• Avoid use entirely 1

Perioperative Considerations

Anesthetic Compatibility

• Suzetrigine does not interfere with local anesthetics due to its selective NaV1.8 targeting 3
• No respiratory depression, sedation, or CNS effects since it does not cross the blood-brain barrier 4, 5
• No cardiac arrhythmia risk as NaV1.8 is absent from cardiac tissue 2

Drug Interactions Requiring Attention

CYP3A Substrates:

• Suzetrigine is a CYP3A inducer and will reduce levels of CYP3A substrates 1, 6
• Adjust doses of sensitive CYP3A substrates when starting or stopping Journavax

Hormonal Contraceptives:

• Patients on progestins other than levonorgestrel or norethindrone must use additional non-hormonal contraception during treatment and for 28 days after discontinuation 1

Avoid grapefruit products during treatment 1

Clinical Efficacy Data

Phase 3 trials demonstrated:

• Statistically significant pain reduction over 48 hours post-abdominoplasty (SPID48 difference: 48.4, P<0.0001) and post-bunionectomy (SPID48 difference: 29.3, P=0.0002) compared to placebo 5
• Pain relief comparable to hydrocodone/acetaminophen 5/325 mg 5
• Adverse events were mild to moderate, with no addiction potential or respiratory depression 5, 2

Common Pitfalls to Avoid

1. Do not give the first dose with food - this delays onset of action significantly 1
2. Do not combine with strong CYP3A inhibitors - this is contraindicated, not just cautioned 1
3. Do not forget dose reduction after dose 4 in patients with moderate hepatic impairment or on moderate CYP3A inhibitors 1
4. Screen for hepatic function - severe hepatic impairment is a contraindication 1
5. Monitor for transient eGFR decline (≤2.5%) - typically resolves spontaneously but warrants awareness 2

Missed Dose Management

Standard dosing patients:

• If one dose missed: take as soon as possible, then resume schedule
• If two or more doses missed: take 100 mg, then resume schedule 1

Patients on modified dosing (moderate hepatic impairment or moderate CYP3A inhibitors):

• Take missed dose as soon as possible
• If next scheduled dose is within 6 hours, skip it and resume subsequent doses on schedule 1