When it comes to antinausea drugs, insurance company coverage restrictions are common and vary widely by insurance, drug, and location, a new analysis has revealed.

Overall, researchers found that nearly 40% of patient-administered antiemetics in Affordable Care Act (ACA) Marketplace plans and about 43% in Medicaid plans were subject to at least one utilization management policy — prior authorization, quantity limits, or step therapy — that could delay or complicate access to care. 

These policies varied significantly, with some plans imposing one or more coverage restrictions on all antiemetic formulations and other plans imposing no restrictions.

Even cheap and effective supportive care antinausea medications were subject to coverage restrictions, and "we're not sure why," said study co-author Michael Anne Kyle, PhD, with the University of Pennsylvania Perelman School of Medicine in Philadelphia. 

The extensive variability in the application of utilization management policies was "surprising," first author Kaitlyn Vu, with Harvard College, Cambridge, Massachusetts, told Medscape Medical News. "We would expect more consistency if policies were truly evidence-based." 

The study was published online earlier this month in JAMA Network Open. 

Restrictions Widespread 

Antiemetics are essential for enhancing therapy tolerability and quality of life in patients with cancer, with level 1 evidence supporting their use. 

Although insurance companies are increasingly applying utilization management tools to cancer care, it's not clear how often these restrictions are used for antiemetics. 

To better understand the landscape of antiemetics restrictions across ACA and Medicaid plans, researchers analyzed 2024 Ideon formulary data for all available ACA and Medicaid plans. The team identified 561 formularies and 348,215 unique drug plan formulations, which represented 93% of the national ACA market and 90% of the Medicaid market. 

The drugs included 13 commonly prescribed oral, self-administered antiemetics, of which five were brand and eight were generic: aprepitant (brand and generic), rolapitant (brand), netupitant-palonosetron (brand), ondansetron (generic), haloperidol (generic), metoclopramide (brand and generic), olanzapine (brand and generic), scopolamine (generic), prochlorperazine (generic), and promethazine (generic). 

The researchers examined each drug-plan entry to determine whether it required prior authorization (preapproval before dispensing), had quantity limits (caps on the amount dispensed), or included step therapy rules (requiring patients to try cheaper options first).

The team found that restrictions were widespread and inconsistent. 

Overall, almost 40% of covered antiemetic medications in ACA plans and 43% in Medicaid plans were subject to some form of utilization management. 

Across plans, there was no standardization on these policies. Overall, 10 ACA plans applied no restrictions to any antiemetics included in the analysis, while two applied restrictions to almost all (99.8%). For Medicaid, two plans applied no utilization management to any antiemetics, while two plans applied some type of restriction to every antiemetic.

In ACA plans, generic antiemetics were more likely to come with restrictions (40.5%) than were brand-name drugs (17.4%), while in Medicaid plans, the reverse was true — brand drugs (82.5%) were restricted far more often than generics (42.2%). 

Adam C. Powell, PhD, who wasn't involved in the study, noted that pharmacy benefit manager (PBM) rebates could play into these restrictions on generic antiemetics.

"PBM rebates play a far larger role in ACA health plans than in Medicaid health plans, making the incentive to restrict generic antiemetics larger for ACA health plans," explained Powell, president of Payer+Provider Syndicate, a healthcare consulting firm in Boston. And "pushing patients to branded antiemetics has the potential to increase rebates." 

Regarding the frequency of specific utilization management policies, quantity limits were the most common restriction, affecting covered antiemetic formulations in 37% of ACA plans and 38% of Medicaid plans. 

Prior authorization applied to 4.5% of antiemetics in ACA plans and about 20% in Medicaid plans. However, brand drugs were more likely to require prior authorization — 9.5% for brand drugs and 4.3% for generics in ACA plans, and almost 73% for brand antiemetics and 18% for generics in Medicaid plans.

Step therapy was used the least overall but was more common in Medicaid than in ACA plans (3% vs 0.4%).

Location and drug type mattered as well when it came to these restrictions. For instance, in ACA plans, prior authorization requirements for antiemetics ranged from nothing in five states (Alaska, Hawaii, North Dakota, South Dakota, and Wyoming) to 27.4% in Connecticut. And for Medicaid plans, the range went from 1.7% in California to 78.5% in Tennessee.

Powell explained that these coverage restrictions are sometimes implemented for clinical, rather than financial, reasons. 

For instance, "quantity limits help ensure that patients are using the drugs episodically rather than chronically," he said. "As antiemetics can have side effects, such as cardiotoxicity, there is a benefit to patients in ensuring their appropriate use."

Kyle acknowledged that "quantity limits are sometimes helpful," as some drugs are only needed for a few doses. "However, we were surprised to see how common these policies were for cheap, generic antiemetics that have well-established clinical benefits for ongoing symptom relief," she noted. 

Additionally, Vu cautioned that the analysis was based on formulary data that don't include information on specific diagnoses or utilization, "so we can't say whether these results are concerning clinically." 

However, she explained, "we know that people with Medicaid and ACA coverage can churn between different types of coverage, and we are concerned that this much variation increases complexity for patients since access across plans is inconsistent."

Funding was provided by a grant to Kyle from the National Institutes of Health, National Cancer Institute. The authors and Powell had no relevant disclosures.