Convenia, the long-acting antibiotic injection that maintains antibiotic levels in a dog or cat’s bloodstream for up to two weeks is the hot topic this week.
Let’s look at another case in which Convenia worked out well.
Fritzi is a Shih Tzu who weighs 20 pounds and has a urinary tract infection. A urinalysis revealed that she had round bacteria, cocci, in her urine. We began an oral antibiotic that has a wide spectrum of effectiveness for cocci, and simultaneously submitted a sample for a bacterial culture and sensitivity test to a laboratory.
Five days later we had results and the sensitivity portion of the test showed that the antibiotic we first chose was effective.
We called Fritzi’s owner to inform them of the results and to ask them to pick up additional antibiotics so that we could have a total of three weeks of antimicrobial therapy.
They were happy to hear that the organism was not resistant, but had a comment about the medication Fritzi was already on. “She’s been vomiting intermittently since she started it. Not every time, but at least once a day. We tried it with food and on an empty stomach, but nothing made a difference.”
Vomiting, with or without diarrhea, are sometime complaints with oral antibiotic therapy. Many antibiotics are associated with these problems.
We gave Fritzi’s owners three choices:
- One was to stick with the same antibiotic but begin giving yogurt several times daily in an attempt to appease the gastrointestinal (GI) tract with beneficial bacteria. The technique works in about 50% of cases and has the advantage of allowing Fritzi to continue to take the same inexpensive antibiotic. Two more weeks of this antibiotic would cost $21.25.
- Option two was to change to a different antibiotic. The next best antibiotic infrequently causes GI upset, but costs more. Two weeks for a Fritzi-sized dog costs $61.40.
- Option three was to give Fritzi a Convenia injection. The active ingredient in Convenia, cefovecin sodium, is a cousin to the first antibiotic we started for Fritzi, but injectable forms almost never cause GI upset, so we should have excellent results in treatment without side effects. The cost? $65.00
How to decide?
If cost were the only factor it might be worthwhile to try to use the original antibiotic, recognizing that there is a 50% chance that vomiting might continue, which would lead to a change of medication anyway and loss of the $21.25.
Weighing the other two options becomes what modern parlance would call a no-brainer. Two weeks of pills twice daily versus no pills, for almost the same cost?
And nearly identical effectiveness.
While the final decision is always the client’s choice, most people would choose the Convenia injection, I’m sure.
I know I would for my own pet.
