Once again, veterinary medicine has been left in the lurch as the availability of opioids has withered due to a DEA-mandated decrease in their production. Although the DEA’s intentions are good in trying to reduce the access to these addictive drugs, this move has the appearance of shorting the veterinary profession while our human anesthesiologists get to treat their patients as usual. We’re forced to rely on veterinary-label opioids still available to us. But a shortage like this is a great time to consider other pain treatments and how they fit into your practice now—or even in a future of plentiful opioids.
We can survive this and any future shortage by using the opioids available to us—namely, butorphanol and the brand name buprenorphine product, Simbadol. Why are these opioids still available? Thankfully, Zoetis has a license to produce these products for veterinary use. This means they have not been subject to the decreased production affecting those opioids that are human generics.
In business with butorphanol
Butorphanol is an opioid with extremely short pain-relieving actions, sometimes as little as 15 minutes, but with a longer sedating action. This sedation has led to confusion about the actual duration of pain-relieving properties. On top of this, it’s not a “strong” opioid and is insufficient for any procedure that is more than mildly painful. This narrows the opportunities where butorphanol may be used, but in the right circumstances it can do an adequate job and keep you from using stronger opioids you’ve got left in stock, saving them for more painful procedures.
Consider the use of butorphanol alone or combined with dexmedetomidine for short and mild to moderately painful procedures, such as expressing infected anal sacs, removing a torn dewclaw or taking hip radiographs of an arthritic dog. Remember, though, that the 15-minute window inherent in the drug may prevent you from even getting local anesthetics on board before the butorphanol wears off.
Bust out the buprenorphine
Buprenorphine is considered a moderate-strength opioid, which can be adequate for all but the most painful of procedures. Although licensed for use in cats as a 24-hour subcutaneous injection for the relief of pain, buprenorphine in the form of Simbadol can be used like generic buprenorphine at the usual intramuscular (IM) dose of 0.02 mg/kg in both our canine and feline patients. Do not use the label dose intramuscularly as it is only intended for the subcutaneous route.
Simbadol is a high-concentration buprenorphine which when administered to cats subcutaneously as directed on the label will have duration of action of 24 hours. Simbadol is not a sustained-release formulation. Given at the lower IM dose to either dogs or cats, Simbadol will last roughly six hours. Given this way, Simbadol is less expensive than the human buprenorphine preparations. I was recently discussing this with Jeff Ko, DVM, a professor of anesthesiology at Purdue University, and he said, “I have been using Simbadol in all routes in both dogs and cats. The routes are IV, IM, subcutaneous (SC) and oral transmucosal (OTM). It’s basically six times cheaper than human buprenorphine on a per-mg basis.”
Look at local anesthetics
Of course, local anesthetics should be the cornerstone of any surgical procedure and should be used wherever practical. Locals are the only analgesic we have—everything else we use is hypoalgesic. This means they have the potential to stop 100% of nociceptive pain, and you can easily learn the techniques for line blocks, dental blocks, testicular blocks, locoregional blocks and epidurals. For some procedures, you can avoid the use of opioids if adequate local techniques are employed.
Thanks to Aratana Therapeutics, we also have the use of Nocita, the 72-hour extended-release bupivacaine. This drug means that we can do away with the lengthy hospitalizations necessary for animals with pain that’s controlled with a constant rate infusion of opioids and other medications. Although Nocita is only licensed for use with cruciate surgery, I’ve successfully used it in any surgery where I previously used regular bupivacaine.
Opt for other drugs
Dexmedetomidine and ketamine. Other drugs to consider—alone or in combination with opioids—are the usual “doggy and kitty magic" formulations that contain dexmedetomidine and ketamine. Both of these drugs have analgesic properties and greatly enhance opioids’ ability to treat pain when used in combination. When they’re appropriate, nonsteroidal anti-inflammatory drugs (NSAIDs) can be a powerful pain killer in the immediate postoperative period. Also consider the use of gabapentin before and after surgery; although there are no great veterinary studies of its use in the perioperative period, gabapentin’s mode of action suggests it may slow or stop the development of postsurgical neuropathic pain.
Maropitant. There’s some evidence that this drug—marketed under the brand name Cerenia (Zoetis) to treat vomiting—has pain-relieving properties, but the evidence doesn’t support its use as a stand-alone pain medication. However, vomiting is a dreaded event for animals. When given prior to surgery, maropitant can stop the emesis associated with opioids and anesthesia, and in some cases stop the associated nausea. Use it as an antiemetic, and if it contributes to pain control, that’s a bonus.
Make nice with nonpharmaceutical options
Nonpharmaceutical options exist for all of us, even without special training.
Cryotherapy. This is the No. 1 easiest thing to do. One study showed that one or two 15-minute icings can lessen pain for up to 24 hours. There are freezer gel packs available that remain pliable when frozen, and there are many “slushy” formulations to buy on the Internet. Avoid the use of frozen peas, which is an emergency home remedy and not adequate for the level of icing we need for our patients.
Compression. Adding this to the icing enhances pain relief. This can be done with the above by adding an Ace bandage over the ice pack. There are also devices that incorporate both icing and compression, such as the Companion Cold Compression Wrap designed for veterinary use.
Therapy laser. This can reduce pain by speeding up the healing process and reducing inflammatory agents. Be careful about using it over an area infused with a local anesthetic, as the resulting increase in circulation can disperse the local anesthetics and work at cross-purposes with them. Only use the laser once the anticipated duration of action of the local anesthetic has passed. Note: No one knows the effect a laser will have on Nocita, so don’t use the laser at all until the fourth day after administration.
Pain evaluations. Employing the use of validated acute pain evaluations, such as the Glasgow forms developed by Newmetrica, help us observe and treat pain as it develops. It’s much easier to treat a developing pain issue than to chase after it once it has reached a higher level. Intervention with something like a micro-dose of dexmedetomidine may be all it takes to keep pain from reaching a critical state. And you can only know to do that if you’re looking for it.
Tissue handling. Employ good techniques while performing invasive procedures. Keep incisions as small as possible. Be considerate about the awkward body positions we put patients in during surgery, especially in our geriatric patients, to avoid a source of nonsurgical pain during the recovery period. Acute pain on top of chronic pain is always worse than acute pain by itself.
Nursing care. Keeping an animal clean, warm and dry in a quiet environment improves the recovery experience. Interact with your patients before, during and after recovery, so they’re less scared and stressed. Those are factors that contribute to pain felt during recovery.
My hope for the future? We see more veterinary-label opioids like Zoetis’ Simbadol and Torbutrol—opioids that wouldn’t be subject to the vagaries of human generic suppliers. In the meantime, brush up on your local anesthetic techniques and get familiar with the other pharmaceutical and nonpharmaceutical pain treatments mentioned above.