Reckitt Benckiser Pharmaceuticals, maker of Buprenex, has stepped up production to make up for shortages of generic injectable buprenorphine, and expects to start meeting current demand next week, a spokeswoman for the company said.

The company is one of four U.S. manufacturers of injectable buprenorphine, a pain reliever made for hospital use in humans, and also used off-label in veterinary medicine. All four manufacturers have been in short supply this year.

Hospira, one of three producers of the generic drug, is short on raw material from its supplier, according to company spokesman Daniel Rosenberg. “Due to this, we’ve had to limit our supplies only to the human market,” he said Wednesday by e-mail. “We are qualifying a second supplier, but I can’t give you any estimates on the timing for being able to supply both markets again.”

Hospira normally sells to Abbott Animal Health, a major supplier of buprenorphine to veterinary clients. Jeff Schaffnit, sales and marketing director at Abbott Animal Health, said Abbott has been unable to obtain the drug from Hospira since late last year.

Another manufacturer of the generic, Bedford Laboratories, stopped making the drug in February. A spokeswoman for the company, Kara Slater, said the decision to cease production temporarily was due to “manufacturing capacity restraints.”

“This is absolutely not a discontinuance,” Slater said. “It definitely is an important product.” She could not give a date when production might resume.

A third maker of the generic drug, PharmaForce, also has temporarily stopped production. Representatives at American Regent, Inc., a subsidiary of Luitpold Pharmaceuticals, Inc., which bought PharmaForce late last year, declined to give specifics except to say the drug is on backorder and will not be available for the next month or two.

At Reckitt, the shortage resulted from the other producers’ supply issues.

“Apparently, the out-of-stock situation was created by various generic manufacturers, which caused an unexpectedly high demand for Reckitt Benckiser Pharmaceuticals’ inventory, above and beyond the company’s normal volume of orders,” said Harriet Ullman, vice president of Feinstein Kean Healthcare, which handles public communications for Reckitt Benckiser.

Ullman said Reckitt increased production of the brand-name drug in order to meet the higher-than-usual demand, but it took time to ramp up.

Crystal Rice, a spokeswoman for the U.S. Food and Drug Administration (FDA) Center for Drug Research and Evaluation, said buprenorphine has been available as 2-mg and 8-mg sublingual tablets, so the agency does not consider the limited supply of injectable drug to constitute a true product shortage.

Availability of sublingual tablets doesn’t help veterinarians, however, as they use the drug in injectable form — administering it by needle or orally, the latter by placing a few drops into the animal's cheek pouch. (The tablets are designed for human use in the treatment of drug addictions, although they have an analgesic effect as well, according to Ullman.)

Dr. Heidi Shafford, a board-certified veterinary anesthesiologist and consultant in Oregon, said the medication is highly popular for veterinary patients. “Large quantities are used on a daily basis,” she said. “This is the most popular opioid analgesic in veterinary medicine.”

Veterinarians began having trouble obtaining buprenorphine in February, judging from comments made on online message boards of the Veterinary Information Network (VIN).

Dr. Carol Tice, a feline practitioner in North Carolina, said the shortage really hurts because she uses the painkiller regularly. “I use it for all surgeries. Declaws, especially old/big cats, go home with doses for the owners to give there,” she said in an interview by e-mail.

"I use it for cystitis cats. I use it for limping cats. I use it for acute arthritic cats. I use it for wounds like abscesses. I use it for dental extractions.”

Tice said the medication is popular because it provides great pain control with minimal side effects, is easy to give and safe.

She sees as good news the prospect that ample supplies of Buprenex are on the way, although the situation is not ideal.

For one thing, the brand-name drug costs her $42.71 for 5 mls, compared with $45.88 for 10 mls of the generic.

She also prefers the packaging of the generic. “It comes in rubber-stoppered vials, making drawing up the solution easier,” Tice said. “Buprenex comes in glass ampules. You need to break off the top and then are left with an open container with ragged glass edges. They are 1 ml each and the doses are always less than 1 ml. We then have to draw up the remainder in a syringe and continue to dispense from that. It’s a pain.”

All the same, Tice said it will be good to have the drug back. “Will I pay twice the price and deal with the ampules until generic is available again? Yep,” she said.

“There are a lot of alternatives for dogs, but cats just don’t tolerate most of them for one reason or another,” she said. “Buprenorphine is a godsend for cats.”

Another reason Tice favors buprenorphine is that although it is regulated like other opioids, it is less stringently controlled than related compounds because it is classified by the federal government as a Schedule III drug rather than Schedule II.

“Morphine and hydromorphine,” for example, she said, “are both (Schedule) II drugs that are just much more of a pain to deal with. I also like not having those drugs in my clinic for whatever potential abuse issues that might arise with my staff ... or even break-ins and theft.”

Shafford said such concerns are common. “There’s an incredible stigma associated with having those medications in your hospital,” said the Oregon anesthesiologist.

She said the stigma and reluctance to use other opioids is regrettable because there are multiple opioid analgesics to choose from that are readily available, more effective and, in many cases, less expensive than buprenorphine.

She also suggests options such as non-steroidal anti-inflammatory drugs (NSAIDs) or gabapentin, and warns against the use of compounded products such as sustained release buprenorphine or buprenorphine gels.

Shafford prepared a chart of alternatives to buprenorphine as a guide for colleagues and for use by the Oregon Veterinary Medical Association. She provided a copy to the VIN News Service (below).

Which options might work in lieu of buprenorphine depends on the situation, of course. Dr. Richard Headley, a practitioner in Indiana, for example, noted in a VIN discussion, “I haven’t found gabapentin all that effective as a sole analgesic unless neuropathic pain is heavily involved.

Headley also said lack of hard data does not deter him from using sustained-release buprenorphine. “I understand her caution ... but I use it frequently and will continue to do so unless evidence is brought forth showing it ineffective,” he said. “It’s hard to overdose buprenorphine, at least to a dangerous level.”

The problem with compounded product, Stafford said, is that “there is no evidence that what they’re providing us is the same product; that it will provide analgesia; that it’s safe to use.”

The risk is the same with all compounded medications, which are not subject to FDA approval and have a complicated legal status.

Illustrating potential problems in the case of buprenorphine, Shafford said some compounding pharmacies are offering the drug in large quantities, on the order of 30-ml vials rather than in the 1-ml vials that are standard. “It’s clearly unethical to provide veterinary clinics with such large vials of buprenorphine that are intended for multi-dose or multi-patient use,” she said, noting that compounding is supposed to serve individual patients with specific needs that cannot be met by available medications that have undergone FDA review.

She said that by using other opioids, her clients have been able to maintain small inventories of buprenorphine for patients that truly need it — a strategy that has enabled them to cope well with the drug shortage.