In an attempt to slow the opioid epidemic, some drugstore chains, states, and health insurers are limiting the number of days for new prescription opioids.

Easy access to prescription opioids since the late 1990s has helped fuel an epidemic that now kills more than 40 Americans every day.

Hoping to slow the epidemic, drugstore chain CVS Health will limit initial opioid prescriptions to seven-day supplies for new patients with acute pain.

This kind of limit has already been imposed by several states. A bill to this effect was introduced in the U.S. Senate earlier this year.

But can prescription limits reduce the number of people who become addicted to opioids?

CVS, which manages medications for almost 90 million people, is the first drugstore chain to impose a limit on opioid prescriptions.

Under the new plan, customers who haven’t filled an opioid prescription through CVS before will only be able to get a seven-day supply of opioid medication for acute conditions.

This includes the use of opioid pain medication after an injury, minor surgery, or a dental procedure.

This doesn’t impact people taking prescription opioids for chronic pain conditions and cancer.

The number of pills dispensed will depend upon the strength of the opioid. Patients will also be prescribed opioids that provide pain relief over a shorter duration instead of a longer one.

If a doctor or dentist prescribes over these limits, the pharmacist will ask them to revise the prescription. Prescribers will also be able to request an exception if they feel the patient’s care warrants it.

The program will go into effect February 1.

The company’s new approach fits with opioid prescribing guidelines released by the Centers for Disease Control and Prevention (CDC) in 2016.

These acknowledge that “long-term opioid use often begins with treatment of acute pain.”

To minimize the risk of opioid dependence, the CDC recommends that doctors prescribe these medications in the lowest dose and for the shortest duration that’s effective at relieving a patient’s pain.

“Three days or less will often be sufficient; more than seven days will rarely be needed,” state the guidelines.

The CDC also cites research showing that high doses of prescription opioids and the use of extended-release opioids have “contributed to the overdose epidemic.”

The CVS plan targets both of these.

However, there’s nothing to stop a patient from asking a doctor for a refill.

“Patients who are in significant pain will have no choice but to get refills; this may result in higher out-of-pocket cost to the patient and substantial inconvenience to both patients and physicians,” Robert Stein, PharmD, JD, a professor of practice for pharmacy law and ethics and healthcare information technology at the Keck Graduate Institute School of Pharmacy, told Healthline.

Stein added that a new federal law allows a “partial dispensing” of Schedule 2 controlled substances such as opioid medications. A doctor could write a prescription longer than seven days, but the pharmacy would only dispense a one-week supply at a time.

CVS will also expand the number of kiosks available at its stores for the disposal of unused medication. This could cut down on unused prescription opioids being misused.

A recent report by the U.S. Substance Abuse and Mental Health Services Administration (SAMHSA) found that about half of people who misused prescription opioids in the past year obtained them from a friend or relative for free.

About 4 percent of people who misused prescription opioids took the pills from a friend or relative without asking.

Walgreens officials didn’t respond to a Healthline email, asking whether the company intends to follow in CVS’ footsteps.

However, the company launched a campaign last month to educate teens about the opioid epidemic.

Express Scripts, the country’s largest pharmacy benefit manager, rolled out a program similar to that of CVS at the beginning of last month.

Snezana Mahon, the company’s vice president of clinical product development, said that an earlier pilot program that included 106,000 patients showed that this limit led to a 38 percent drop in hospitalizations and a 40 percent decrease in emergency department visits.

Mahon also said that the average opioid prescription written for patients covered by its programs was 22 days.

Stein thinks opioid limits will also “indirectly educate prescribers to avoid writing prescriptions for excessive quantities of opioids.”

While the seven-day limit fits with the CDC’s guidelines, even that carries a risk of opioid dependence.

A CDC report from earlier this year found that the risk of long-term opioid use increased with each additional day of taking the pills — starting with the third day.

The report noted that the “sharpest increases in chronic opioid use” occurred after 5 days and 31 days of opioid therapy.

The risk also spiked when a patient was given a refill, a high-dose prescription, or an initial 10- or 30-day supply.

Several states — including Arizona, Connecticut, Delaware, Maine, Massachusetts, New York, Pennsylvania, Rhode Island, and Vermont — have laws limiting initial opioid prescriptions to around seven days.

New Jersey has the strictest law in the nation — a five-day limit signed into effect by Gov. Chris Christie in February.

Philadelphia-area Independence Blue Cross also set a five-day limit for initial opioid prescriptions for people covered by its health insurance plans.

And earlier this year, Sens. John McCain (R-Ariz.) and Kirsten Gillibrand (D-N.Y.) introduced a bill that would set a seven-day limit for opioid prescriptions for acute pain. The bill remains in committee.

Critics of state limits for opioid prescriptions — including some doctors — are worried that limits will restrict a doctor’s ability to treat patients individually.

“A one-size-fits-all approach to medical care and specifically pain management seems unwise,” Stein told Healthline. “An orthopedic patient may need weeks of opioid pain control, making the limit inconvenient for those physicians and their patients. A dental patient, on the other hand, should reasonably require no more than a seven-day supply.”

Of course, a bigger question remains: What’s the most appropriate length of an opioid prescription for different acute conditions?

A recent study in JAMA Surgery adds some clarity to that.

Researchers found that the ideal prescription length for general surgery likely falls between four and nine days. For women’s health procedures, it’s between 4 and 13 days. And for procedures like knee and hip replacements, it’s between 6 and 15 days.

Studies like this might make it easier for states, drugstores, and insurers to set opioid prescription limits that still allow doctors to provide the care they feel is needed.