Who Should Not Take Journavx
Journavx (suzetrigine) is absolutely contraindicated in patients taking strong CYP3A inhibitors and should be avoided in patients with severe hepatic impairment (Child-Pugh Class C). 1
Absolute Contraindications
Strong CYP3A Inhibitors
Concomitant use with strong CYP3A inhibitors is the only absolute contraindication listed in the FDA label 1. Strong CYP3A inhibitors significantly increase suzetrigine and its active metabolite (M6-SUZ) exposures, which may cause adverse reactions 1.
Common strong CYP3A inhibitors to avoid include:
- Ketoconazole
- Itraconazole
- Clarithromycin
- Ritonavir and other HIV protease inhibitors
- Nefazodone
Situations Requiring Avoidance
Severe Hepatic Impairment
Avoid use in patients with severe hepatic impairment (Child-Pugh Class C) 1. Patients with moderate hepatic impairment already demonstrate higher systemic exposures of suzetrigine and M6-SUZ compared to those with normal hepatic function, increasing the risk of adverse reactions 1. The safety and pharmacokinetics in severe hepatic impairment have not been established.
Relative Contraindications and Special Precautions
Moderate Hepatic Impairment (Child-Pugh Class B)
While not contraindicated, these patients require dose reduction: after the initial 100 mg dose, give 50 mg every 12 hours for doses 2-4, then reduce to 50 mg every 24 hours (instead of every 12 hours) for subsequent doses 1.
Moderate CYP3A Inhibitors
Patients taking moderate CYP3A inhibitors (e.g., diltiazem, verapamil, fluconazole, erythromycin) require the same dose reduction schedule as those with moderate hepatic impairment 1.
Hormonal Contraceptive Users
Patients taking hormonal contraceptives containing progestins other than levonorgestrel or norethindrone must use additional non-hormonal contraceptives (such as condoms) or switch to alternative contraceptives during Journavx treatment and for 28 days after discontinuation 1. This is because suzetrigine is a CYP3A inducer and may reduce the efficacy of these hormonal contraceptives 1.
Acceptable hormonal contraceptive options include:
- Combined oral contraceptives with ethinyl estradiol plus levonorgestrel or norethindrone
- Intrauterine systems
- Plus barrier methods during and 28 days after treatment
Patients on Sensitive CYP3A Substrates
Exercise caution when Journavx is used with sensitive CYP3A substrates or CYP3A substrates where minimal concentration changes may lead to loss of efficacy 1. Dosage adjustment of these concomitant medications may be required when initiating or discontinuing Journavx 1.
Clinical Considerations
Grapefruit Products
Patients should avoid food or drink containing grapefruit during treatment with Journavx 1, as grapefruit is a moderate CYP3A inhibitor.
Pregnancy and Lactation
While not explicitly listed as contraindications in the provided FDA label excerpts, standard practice would require careful consideration in these populations given the lack of established safety data.
Common Pitfalls to Avoid
- Do not overlook medication reconciliation for CYP3A inhibitors—many commonly prescribed medications fall into this category
- Remember that the contraindication applies to strong CYP3A inhibitors; moderate inhibitors require dose adjustment but are not contraindicated
- Do not forget the 28-day washout period for hormonal contraceptive interactions after stopping Journavx
- Verify hepatic function before prescribing, as dose adjustments are critical for moderate impairment and the drug should be avoided entirely in severe impairment