Will Metacam immediately counteract the affects of Phenobarbital?

I had a dog who was epileptic and she was on phenobarbital. We had been noticing she was in some pain, maybe, 6 months after she originally went on phenobarbital after a spell of seizures. Anyway, the vet gave her a dose of metacam in order to relieve the pain and also gave us another 2 syringes for the weekend if the pain persisted, since it was a long weekend. The following day we gave her another dose just so she could be comfortable.Then, about 10 hours after that, she began having seizures. Unfortunately it was so severe that she didn't make it through them. Now, I understood that phenobarbital wasn't a cure and that there could be some breakout seizures infrequently. However, she was having a very minor seizure about every hour. It almost wasn't noticeable at times, although she did have one bad one which prompted us to call the vet emergency clinic. Anyway, I know, now, that metacam counteracts the effectiveness of phenobarbital. Does this take effect immediately? Could it be that the metacam caused this spell of seizures to break through? I'm not interested in suing anyone, but I'd really like to let me vet know about this interaction if it could have caused the issue, so other people don't experience the same issue. Thanks in advance.

I'd like to start by first saying that I'm really sorry for your loss. The two medications don't work well together because of how they interact in the liver, and Metacam begins working for pain about 8 hours after being taken. So I'm thinking it would follow that the medicines would clash around the same time the Metacam would begin working. From what you've said, I'm fairly certain that it was the Metacam/phenobarb interaction that caused the seizure. I find it irresponsible of the vet to have prescribed your dog those two medications together.

Like any medication, Metacam does carry certain potential side effects and should only be prescribed and used under the direction of a vet - as was done in your dog's case. However, I was unaware that Metacam counteracted with Phenobarb - especially 10 hours out. In fact, I have owned two dogs in the past who suffered from seizure disorders, and one of them was prescribed Metacam by our vet after he was injured - while on Phenobarb.However, it does sound as though your dog's seizure disorder was severe and escalating, and it likely that this gran mal event would have happened sooner or later, regardless of the barbiturates. I am so very sorry for your loss and for how upsetting it was for you to watch your dog in seizure.You had him under a vet's care and you did right by your dog - always know that.ADD: Just for my own info., I did a little checking. I did find that Metacam and Phenobarb prescribed together MAY cause ineffectiveness in one or the other and that liver monitoring should be conducted when they are used in tandem. However, it is not 100% conclusive (in my dog's case, he did well when on both meds) that it always does. Was your vet monitoring her at all? That may be a good question to ask him.

I am so sorry that you have lost your dog. Although I have had dogs forever, none of them have had epilepsy.Metacam, is a medication which was prescribed for my dogs who had other problems.Although you don't intend to sue, I think that you should Google the "side effects" of Metacam.I guess that you are in the U.K. consequently you could complain to the Royal College of Veterinary Surgeons. Unfortunately they appear to be a "closed shop" who protect vets even when they are negligent.Take care, it takes forever to get over the death of a beloved dog.