Taking a look at a new antimicrobial product

It's important to look at the pros and cons, if any, and ask questions

With new animal health products it is not just the effectiveness of the product that makes a difference.

These days all antimicrobials, NSAIDs and a few other products are prescription products with most coming under the VCPR (veterinary client-patient relationship) requirement. NSAIDs stands for nonsteroidal anti-inflammatory drugs.

It is best that producers educate themselves on new, emerging products that may benefit their operation or management style. Everyone needs to realize that any new products have passed rigorous testing.

Even though they may be generics, they have passed the same testing as the original brand-name product.

For example, a new product called Zeleris contains essentially two generic products that have been combined into a new product. The products are florphenical and meloxicam — two very well- accepted and well-used products combined to produce an antibiotic for things like pneumonia and which also contain an anti-inflammatory or pain control component.

These days, generic drugs should be the equivalent to the brand- name drug, but the carrier may be different and there may be other subtle changes. Zeleris was no doubt developed as a competitor to Resflor, the tried and proven number one product used to treat clinical pneumonia in Canada. As a first- line treatment against pneumonia, Resflor contains a category-three antibiotic and banamine, which is also an NSAID.

When a new product hits the market and is equivalent to other products, a veterinarian usually reviews the literature and decides whether to prescribe it. Some may prescribe the new product to give it a try while others might want to stay with the proven product following the adage of “if it ain’t broke, don’t fix it.” It is up to the producer to decide which product to use — and neither is wrong.

Features worth checking

What I am finding with new, similar products are the sometimes subtle different features that may attract the vet/producer. Zeleris has three that in my mind make it a bit different. It comes in a plastic bottle, has a lower dose than Resflor and is more syringeable, meaning the viscosity of the medicine makes it easier to load and inject with less effort.

In regards to plastic bottles, there are great plastics out there these days and I would hope the regulatory people will approve more antimicrobials in plastic bottles. It makes sense to reduce breakage during shipping and eliminate the need for protective plastic shrouds around a glass bottle during shipment. It reduces the amount of packaging, reduces waste and hopefully reduces overall cost. Plastic is by far the best new way to go. It is user-friendly and I know of several antimicrobials already sold in plastic bottles so I see no reason why all can’t be packaged that way.

The lower-dose feature of Zeleris does add convenience. Resflor used at the six cc per 100 pounds was used extensively because the efficacy was so darn good. If efficacy is excellent a lot of inconvenience can be tolerated. Zeleris is a bit lower at 4.5 cc per 100 lbs., so there’s a slight convenience on administration. Zeleris should be administered as a single subcutaneous dose at a rate of 40 mg florfenicol/kg bodyweight and 0.5 mg meloxicam/kg body weight (i.e. 1 mL/10 kg bodyweight). Do not administer more than 15 mL at each injection site. The injection should only be given in the neck area.

The syringability issue really only comes up in colder weather and I know the company that makes Resflor provides bottle warmers to try and keep the product as syringable as possible so they have found a way around that.

I have heard of the odd case of swelling related to Zeleris. That is possible with its more watery product so one has to see how much swelling it actually might produce. The only question for producers is whether they can put up with whatever swelling, if any.

With Resflor used widely I have never seen any swelling personally. That is why a person needs to try these products and make their own judgement.

There are actually three antimicrobial products that carry the florphenicol molecule, so the competition may affect price. But it is best to check with your veterinarian first to determine if the products can be used interchangeably. It should be noted all florphenicol products have a longer withdrawal of 56 days than other antibiotics, and Zeleris is no different.

Your veterinarian has the VCPR with you. So don’t be afraid to ask them about any new products on the market. Sometimes all vets need to try new products first hand to see if they’re effective.

It is important that the various pharma companies keep the market competitive and keep being innovative. It is amazing in this day and age how often simple things like a plastic bottle and ease of administration can be important decisions in which product we choose both as veterinarians and producers.

About the author


Roy Lewis is an Alberta-based veterinarian specializing in large-animal practice. He is also a part-time technical services vet for Merck Animal Health.



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