Journavx (suzetrigine): state of practice

Why this drug matters for psychiatric practice

The intersection of psychiatric medication and acute pain is where a lot of iatrogenic complications happen. A patient on sertraline gets tramadol after a knee replacement, and now there's serotonin syndrome risk plus the seizure threshold from tramadol's SNRI activity. A patient on a MAOI gets meperidine and ends up hospitalized. A patient on lithium takes ibuprofen for a week and lithium level climbs into toxicity. A patient in early recovery from opioid use disorder is offered oxycodone for post-surgical pain and the recovery collapses. Every one of these is preventable if there's a non-opioid, non-serotonergic option with a real efficacy signal for acute pain.

That's the space suzetrigine is trying to fill. It's a peripheral drug: it acts on sodium channels expressed only in dorsal root ganglion sensory neurons, not on central neurons. There's no crossing of the blood-brain barrier at therapeutic doses. No serotonin activity, no norepinephrine reuptake inhibition, no opioid receptor binding, no dopamine effect. From a psychiatric interaction standpoint, it's inert.

For pain specialists, the drug is a class-of-one non-opioid, non-NSAID acute pain drug. For prescribing psychiatrists working with surgeons and primary care on shared patients, it's a specific option to know about when the standard alternatives are contraindicated or risky.

What the trials showed

Two Phase 3 trials supported the approval:

Post-bunionectomy pain: 1,118 patients randomized to suzetrigine 100 mg loading dose then 50 mg every 12 hours, hydrocodone-acetaminophen, or placebo, for 48 hours after surgery. Suzetrigine's mean pain reduction at 48 hours was slightly better than the hydrocodone-acetaminophen comparator and significantly better than placebo.

Post-abdominoplasty pain: 1,073 patients on the same protocol. Similar results: suzetrigine's pain reduction was comparable to hydrocodone-acetaminophen and significantly better than placebo.

The effect size versus the opioid comparator was modest. This is not a drug that outperforms opioids by a large margin. It's a drug that produces roughly opioid-equivalent acute pain relief without the opioid side effects. That's the value proposition.

A parallel Phase 2 trial in painful lumbosacral radiculopathy (LSR) did not meet its endpoint. Neuropathic pain does not appear to respond to suzetrigine as consistently as nociceptive post-surgical pain does. This is consistent with the mechanism: Nav1.8 blockade is more relevant to inflammatory and mechanical pain than to neuropathic pain.

Dosing

The approved regimen is a 100 mg loading dose followed by 50 mg every 12 hours for the acute pain course. The label allows up to 14 days of treatment. In the trials, most patients were on the drug for 48 to 72 hours after surgery, which is the typical acute pain window.

There is no titration. There is no dose adjustment for weight or age. There is no need for TDM.

Renal impairment: no dose adjustment needed for mild to moderate impairment. Severe renal impairment (CrCl below 30) is not well studied and requires clinical judgment. Hepatic impairment: no adjustment for mild impairment. Moderate to severe hepatic impairment is not well studied and the drug should be used cautiously.

Missed doses: if a dose is missed by less than 6 hours, take it. If more than 6 hours, skip and resume the next scheduled dose. Do not double up.

Adverse events and tolerability

Trial adverse events were modest overall. The most common were nausea (about 11 percent), constipation (7 percent), headache (7 percent), and dizziness (5 percent). Discontinuation rates for adverse events were around 3 percent in the trials.

Notably absent from the profile: no sedation, no respiratory depression, no confusion or delirium, no addictive potential. That's the point of the drug: acute pain relief without the opioid class effects.

The most important safety signal is a small increase in creatine phosphokinase (CPK) seen in some patients, likely because Nav1.8 channels are also expressed on some peripheral muscle fibers. Clinically significant myopathy was rare in the trials, but it's the reason the label warns about muscle symptoms and recommends stopping the drug if severe muscle pain or weakness develops.

CYP3A4 metabolism: suzetrigine is metabolized primarily by CYP3A4. Strong CYP3A4 inhibitors (ketoconazole, clarithromycin, ritonavir) raise suzetrigine levels and worsen side effects. Strong CYP3A4 inducers (rifampin, carbamazepine, phenytoin, St. John's Wort) lower levels and may blunt efficacy. Both are label warnings.

Where suzetrigine fits right now

Three practice scenarios where the case is clearest:

The first is post-surgical acute pain in a patient on serotonergic psychiatric medications where tramadol or codeine would raise interaction risk. The classic example is the patient on sertraline (or venlafaxine, or duloxetine) who needs 3 to 5 days of opioid-comparable pain relief after dental extraction, minor surgery, or bunionectomy. Suzetrigine is a clean choice.

The second is post-surgical pain in a patient in recovery from opioid use disorder where any opioid exposure is a real risk to the recovery. Non-opioid multimodal analgesia (acetaminophen, NSAIDs where safe, regional anesthesia, ice, mobilization) is standard, and suzetrigine adds a real efficacy tier that wasn't available before.

The third is post-surgical pain in an older adult where opioids raise fall risk, confusion, delirium, and constipation risk in a population already vulnerable to all of them. Suzetrigine sidesteps the classic geriatric opioid pitfalls.

Where suzetrigine doesn't fit right now: chronic pain (not indicated, and the mechanism suggests it wouldn't work for long-term neuropathic or centralized pain), neuropathic pain (the Phase 2 lumbosacral radiculopathy trial failed), pediatric acute pain (not studied), severe post-surgical pain where opioids are the appropriate mainstay (the effect size compared to hydrocodone-acetaminophen was modest, not massive; suzetrigine doesn't replace opioids for major surgery).

Cost and access

List price is around $16 per 50 mg tablet, or roughly $30 for a 100 mg loading dose plus about $32 per day thereafter. A typical 3-day post-surgical course runs about $150 to $200. Insurance coverage in early 2026 is uneven. Some payers have added suzetrigine to formularies as a preferred non-opioid for acute post-surgical pain, especially in the context of opioid stewardship. Others require prior authorization documenting contraindication to opioids or NSAIDs.

The manufacturer (Vertex) offers a copay assistance program that brings out-of-pocket to under $50 for commercially insured patients meeting eligibility criteria.

Practical implication for prescribers: know your local formulary and PA requirements. For a patient with clear opioid contraindications (SUD history, drug interaction with serotonergic psychiatric medication, older adult at fall risk), documenting the reason clearly in the PA note is what makes the difference between coverage and denial.

Common questions

Is suzetrigine as effective as opioids? In post-surgical acute pain over 48 hours, comparable to hydrocodone-acetaminophen. Not clearly better, not clearly worse. For severe pain requiring higher-tier opioid regimens (morphine, oxycodone at higher doses), suzetrigine has not been tested and is not expected to substitute. It's a low-tier opioid alternative for moderate acute pain, not a high-tier opioid alternative.

Can suzetrigine be combined with acetaminophen or NSAIDs? Yes, and this is expected practice. Multimodal analgesia including scheduled acetaminophen plus an NSAID plus suzetrigine is a reasonable post-surgical protocol for patients where opioids are best avoided. No known negative interaction with common analgesics.

Can it be combined with an opioid? Yes if needed. Suzetrigine's mechanism is orthogonal to opioid receptor mechanism, and the trials allowed rescue opioid use. In practice, using suzetrigine as the scheduled analgesic with a small opioid dose available for breakthrough is a plausible framework for post-surgical pain where the surgeon expects opioids might be needed but wants to minimize total opioid exposure.

Is suzetrigine safe with lithium? No known clinically significant interaction. Suzetrigine is not renally excreted to a degree that would affect lithium clearance. Suzetrigine is not metabolized through lithium-relevant pathways. This is one of its advantages: unlike NSAIDs, which can raise lithium levels significantly by reducing renal clearance, suzetrigine does not carry that risk. For a patient on lithium who needs 3 to 5 days of acute pain relief, suzetrigine is a much safer option than an NSAID.

Is it safe with clozapine? Yes as far as known. No serotonergic activity, no anticholinergic burden, no orthostatic risk that would compound clozapine's known cardiovascular liability. Not a substitute for clozapine's own monitoring requirements, but for acute pain during a clozapine treatment course, suzetrigine is a clean choice.

What about breastfeeding? Label recommends against breastfeeding during treatment and for 24 hours after the last dose. Suzetrigine's transfer into breast milk is not fully characterized. Given the acute (48-hour) treatment paradigm typically, pumping and discarding through the treatment course is often feasible.

Is it safe in pregnancy? Not studied in pregnancy. Animal reproductive toxicity data showed dose-related effects at doses higher than human exposure. The label recommends against use during pregnancy unless benefit outweighs risk. Most acute pain in pregnancy is managed with acetaminophen plus non-pharmacologic measures, with opioids reserved for severe pain.

How long can it be used? Label allows up to 14 days for acute pain. Beyond that, the drug is not indicated. Chronic pain has not been shown to respond to suzetrigine in trials.

Can psychiatrists prescribe it? Yes, no scheduling restriction, no special certification required. In practice, suzetrigine prescribing usually happens through the surgeon or primary care for the acute pain indication. Psychiatry's role is often coordination: advocating for suzetrigine over tramadol or codeine when the patient is on serotonergic medications, or coordinating pain management planning with the surgical team before a scheduled procedure.

What's next

Vertex has additional NaV1.8 and Nav1.7 sodium channel blockers in development, including compounds targeted at chronic pain rather than acute. If any of them succeed for neuropathic or chronic pain, the class becomes a major addition to pain medicine. Suzetrigine itself is being studied in additional acute pain settings (post-cesarean, orthopedic surgery beyond bunionectomy). Label expansion is likely if the trials succeed.

The broader question is what happens to opioid prescribing patterns as non-opioid alternatives with real efficacy signals become available. Historically, non-opioid alternatives have had smaller effect sizes and less clinician confidence. Suzetrigine is close enough to opioid-equivalent for moderate acute pain that formularies and clinical pathways are beginning to reflect the shift. Whether this translates to reduced opioid prescribing at population scale takes years to see.

For psychiatric practice, the immediate practical impact is having a specific drug name to suggest when a surgeon or primary care clinician is considering tramadol or codeine for a patient on an SSRI, or oxycodone for a patient in recovery. That conversation is easier when there's a real alternative to recommend.

Sources

• Bertoch T, Bergese SD, Habib AS, et al. Safety and efficacy of suzetrigine in acute post-surgical pain: pooled analysis of two Phase 3 randomized clinical trials. Anesthesiology. 2025.
• Journavx (suzetrigine) tablets, for oral use. Prescribing information. Vertex Pharmaceuticals; approved January 30, 2025. Available via DailyMed.
• Osteras N, McCarberg BH, Fu R, et al. Suzetrigine for painful lumbosacral radiculopathy: a randomized clinical trial. JAMA. 2025 (Phase 2 negative trial).
• Bennett DL, Clark AJ, Huang J, Waxman SG, Dib-Hajj SD. The role of voltage-gated sodium channels in pain signaling. Physiol Rev. 2019;99(2):1079-1151.
• Centers for Disease Control and Prevention. Clinical Practice Guideline for Prescribing Opioids for Pain, 2022 (context for non-opioid preference in acute pain).