VetInfo Digest                                          December 2006

Table of Contents:

Compounding Pharmacies

Getting a Grip

Sedatives and Tranquilizers Can Be Helpful

Pets Mask Pain

Too Many Medications to Know Them All

Too Many Medications to Stock Them All

Splitting Medications

Medication Form Matters

Drug Reactions

This Month's Note:

Almost every profession or trade has a body of information that becomes referred to as the "trade secrets". These are usually not actual secrets but when you're not working with the information or skills necessary to perform a job on a daily basis it is hard to know all of the important information that applies, much less all the little bits of trivia that are helpful, but not absolutely necessary to know. There really aren't all that many trade secrets in veterinary medicine but there are a few things that might be useful to pet owners so I'm going to devote part of this issue of the VetInfo Digest to discussing trade secrets.

For all of you who have been following Henry's progress, he is now so playful and active that we have been wondering what exactly possessed us to get a puppy! So far our best conclusion is temporary insanity.

Compounding Pharmacies

I am really good at giving pills to dogs and cats due to years of experience. I still meet a dog or cat every now and then who I can't give a pill to, though. There are several solutions to this type of problem. For dogs it is often effective just to hide the pill in a treat that the dog will swallow readily, like liverwurst or peanut butter. This rarely works for cats, though. Currently we are happy with a product called "Pill Pockets (tm)" that are made in dog and cat versions. These are pretty sticky and it is hard for a pet to separate the treat from the pill. They still work better in dogs than in cats but it is worth a try for either species. When this doesn't work there is the option of having the medication "compounded" into a form that the pet is willing to take.

Compounding is the process of making medications. For many years pharmacists pretty much made all medications in the store. As mass production of pills, syrups and solutions became the norm this aspect of pharmacy practice declined.

Simple compounding consists of taking a pre-manufactured medication and altering it to make it into a form that the pet will readily accept, such as a flavored pill, gel or liquid. In general it is reasonably safe to do this but it is important to recognize that it is possible to alter the way a drug is absorbed or utilized by the body by changing it from a pill to a powder, gel or liquid. Some pill form medications must retain their film coating to be efficiently absorbed by the body, for instance. It is important that the person who changes the medication's form have access to the information on how the drug is absorbed and utilized in the body. For this reason we usually rely on a compounding pharmacy even though there are kits made for veterinarians that allow flavoring of medications. It is possible to do a good job of flavoring medications in a veterinary practice but it does involve having time to pay attention to the details.

At home compounding consists of doing things like putting all of the day's medications into a gel capsule to make it possible to give one capsule rather than three individual medications. Another example would be putting a powder such as tylosin (an antibiotic) or fenbendazole (a dewormer) into capsules to make it easier to administer. Gel capsules are often available from pharmacies or your veterinarian might keep some on hand to make it easier to administer medications to some patients.

More complex compounding, which is usually done almost exclusively by compounding pharmacies, involves making medications from bulk ingredients or transforming the method a medication is administered substantially. Technically at this time it is illegal to use bulk ingredients to produce a medication but since this is the only way to obtain some medications that have proven their usefulness in veterinary medicine it is a practice that the FDA seems to be tolerating for the time being. In the United States the medication that best fits this description at the current time is potassium bromide, used for seizure control in dogs. It is not available as an approved drug in any form and must be made from bulk ingredients directly. Another medication that would not be available at the current time without the use of bulk ingredients is diethylstilbestrol (DES), used to treat incontinence in female dogs. Compounding pharmacies are the only source of these medications.

Another form of compounding that can be very helpful is using an approved medication that comes in one form, such as an injectable base or pill form, and transforming it into another form that can be more easily administered. When this can be shown to be necessary it is probably legal to make this type of medication. The best example of this is the use of methimazole tablets, used to treat hyperthyroidism in cats, to make a transdermal gel that can be administered by applying it to the skin on the inside of the ear. Transdermal gels are the most convenient way for many cat owners to administer methimazole and it seems to work without causing problems even in cats who vomit after administration of methimazole tablets. There is often a need to make medications into a form that can be administered by people who can't give pills. A common use of this in veterinary medicine is the manufacture of prednisone liquid from prednisone tablets since there is not a liquid version of prednisone approved for use in pets.

There is a chance of changing the way a medication works by compounding it. Over time methods of limiting this possibility have been worked out and published but these are still mostly guidelines rather than well documented scientific studies. For this reason, you have to be careful in the selection of medications to be compounded. It is best to restrict the use of compounded medications to situations in which there is a good way to tell if the medications is working well. An example of this is the use of transdermal methimazole for hyperthyroidism in cats. It is relatively easy to test thyroid levels in the blood stream to ensure that the medication is having the desired effect. If it is necessary to have a medication such as an antibiotic made into a different form it is harder to tell if it is working well. In these cases you have to try as hard as you can to realistically evaluate the success using whatever means is possible, such as fewer skin sores, a drop in fever or some other observable change in status.

The laws regarding compounding are confusing enough that some veterinarians are reluctant to write prescriptions for compounded medications. In some areas there is very limited access to pharmacies that can legally compound medications. For these reasons compounding may not be mentioned or advocated even when it might be very helpful for a particular patient. It is still worthwhile to ask about the possibility of getting a medication made into a flavored form or about the use of a transdermal gel when giving methimazole to a difficult to pill cat. Sometimes your vet just isn't aware that you are having trouble giving the medication and need an alternative route of administration.

Unfortunately, there are some clearly illegal uses of compounding that are still quite attractive to some veterinarians and veterinary clients. Two of the more attractive of these are the use of cyclosporin for dry eyes in dogs and the use of fludrocortisone for pets who have Addison's disease (hypoadrenocorticism). Cyclosporin is available in a commercial form as an eye ointment. Due to this it would only be legal to alter it using the original product. Over the years this ointment has not always been available so it was common for veterinarians to write prescriptions for oral cyclosporin to be made into an eye drop. This is OK when the ointment is off the market but illegal when it is available. It is also illegal for compounding pharmacies to make fludrocortisone out of bulk ingredients since there is an approved FDA product. The major reason that veterinarians would consider writing prescriptions for compounded fludrocortisone is cost. The FDA approved product can cost several dollars a day at necessary doses but the compounded product was often available for much less. Unfortunately, avoidance of high cost is not an approved reason for compounding so this is not something that can be done, legally. Using compounding to avoid high costs of importing drugs for special use, such as trilostane for Cushing's disease or pimobendan for heart disease isn't legal.

For the veterinary client the legality of compounded medications is less of an issue than it is for veterinarians. It is very unlikely that the FDA would ever try to go after an individual for using a prescribed compounded medication to treat a pet. It is much more likely that the FDA would target the veterinarian or the pharmacy involved in distributing the compounded medication. If your vet or pharmacy is comfortable dispensing a compounded medication and you can tell that it is having the desired effect there is no reason for you to worry about the drug laws except to consider the fact that the medication may not always be available in the future. Be understanding if your vet is reluctant to write prescriptions for certain compounded medications, though. His or her license may be on the line. There are certain medications which require compounding that are useful enough that there would be a great deficit in our ability to treat patients without them. I think that this pretty much ensures that compounding will continue to be available but there aren't any absolute guarantees right now since this is a gray area in prescription laws.

Get a Grip

You may have noticed that your veterinarian doesn't like it when you hold your pet during examinations or minor procedures such as vaccination or toe nail trimming. Many of my clients seem to think that they can hold their pet in a way that it won't bite anyone but which doesn't stress the pet at all. I wish that were true. The reality is that pets who are inclined to bite during examinations are usually able to manage to bite someone when their owner is providing restraint. This is not always true but it is true more often than not.

Your vet and the veterinarian's staff are better at restraining your dog than you are, almost all the time. More veterinary clients are injured trying to restrain uncooperative pets, or attempting to assist veterinary staff in restraining dogs or cats than in any other way at veterinary hospitals. This is a major problem for veterinary hospitals because the way that liability works in most states the veterinarian and his or her staff are responsible for restraint of the pet when they are present. The reasoning behind this is that they are professionals providing a service which includes knowing how to restrain the pet properly so that no one is injured. If the vet makes the judgment that you are able to restrain your pet and allows you to do that but your pet bites you the veterinarian is usually liable for damages related to the bite injury. As you can imagine, this makes many veterinarians extremely reluctant to allow you to hold your pet during examinations and for minor procedures.

Let the veterinary staff provide the restraint and don't interfere. If you think that you pet is being harmed ask that the staff stop whatever they are doing. If you do resort to this keep in mind that it may end the visit, whether or not the veterinarian is done with examination or whatever procedure set off the problem. In a very limited number of circumstances it will impossible for the veterinarian to stop a procedure right at the moment that you become upset about restraint. This can happen when a needle has been inserted and a pet won't allow it to be removed, for instance. The veterinarian pretty much has to provide adequate restraint to get to the point that stopping the procedure won't harm the pet.

There are a few things that you can do to limit the need for restraint at the veterinarian's. Bringing some really special treats to all of the puppy visits and giving them to distract the puppy from vaccinations or other procedures can make future visits much less frightening. It isn't necessary to bring your own treats if your vet is the type who gives lots of treats, anyway. We try to give treats to most of our canine patients on every visit. Cats are as likely to accept treats but give them to cats who will accept them. Dogs and cats who are food oriented often seem happy to come to our office, despite the examinations and vaccinations.

Some pets are better when their owners are in the room and some are better when their owners are not in sight. This is something that has to be discovered over time. I am very reluctant to separate pets from their owners because I really think that people should be aware of what we are doing to their pets and how we are treating them. However, I know that some veterinary hospitals routinely move pets to another room for any treatment procedures. Personally, I think the best approach is for people to be present until we know that a pet is reacting aggressively to us. We try working with the aggressive dog or cat without the owner's presence in this case. Sometimes it really helps. Other times we have to look for other alternatives.

Sedatives and tranquilizers can be very helpful.

We have some cats and dogs in the practice who do better during physical examinations if they have been sedated prior to the visit. It is very important to keep in mind that some pets get noticeably more aggressive when they are sedated. I think of this as sort of a "mean drunk" phenomenon. For pets who want to be aggressive but are inhibited in their aggression, sedation may lower the inhibition level and result in a stronger tendency to bite. You must work very carefully around pets who have been sedated or tranquilized until it is clear that they are providing the desired effect and not the opposite effect.

When pets respond well to sedation it is often possible to stop using sedatives after a few visits because the pet has a chance to figure out that the examination process isn't as scary as it seemed. This is a nice added benefit to sedation when it works.

We usually try to send home a sedative like acepromazine (cats and dogs) or to call in a prescription for a tranquilizer like diazepam (Valium Rx) or alprazolam (Xanax Rx) (usually dogs only) and to have the owner give the medication 15 to 30 minutes prior to leaving the house to come to our office. This gives some time for the sedative to work.

While we would prefer not to have to use sedatives they can be extremely helpful for some patients, making office visits much less stressful for everyone involved.

Pets Mask Pain

One of the most disheartening problems we deal with on a routine basis is the failure of many pet owners to recognize when their pet is in pain, especially chronic pain associated with degenerative diseases. It is hard to tell when a dog is in pain and it is even harder to tell when a cat is in pain. Almost every week I have a patient who I can clearly tell would benefit from pain relief whose owner can not be convinced their pet is in pain. People seem to expect pets to vocalize pain in some manner. This just isn't how most pets express pain. They show it by restricting their activities or in difficulty rising up from laying down. There may be changes in appetite or sleep patterns. This includes eating more or eating less and sleeping more or sleeping less.

If your veterinarian suggests trying pain relieve medications at least give it serious consideration. I try to talk people into trying a reliable pain reliever for at least a week to ten days to try to gauge how much of their pet's disability or behavioral changes relates directly to pain. Often they are very surprised how much better a little pain relief can make their pet feel.

I think that a lot of pets would be better off if people just assumed they were in pain when it was reasonable to suspect they might be. Pain should be expected after surgery, in older pets due to degenerative joint disease and when injuries that would hurt if you had them (such as a broken rib) are present. If your vet doesn't discuss pain relief ask about it.

It took us a long time to figure out a way to provide pain relief for cats but we are getting some better options now. For post-surgical pain the injectable pain reliever meloxicam (Metacam Rx) is now approved for pets and will provide pain relief for 24 hours. The injectable form of buphrenorphine can be given orally and it isn't even necessary for the cat to swallow it for it to have an effect. This makes it possible to dispense doses of buphrenorphine for home administration for cats. Since cats can be hard to give pills to this makes a very nice pain reliever for short term use. For long term degenerative joint pain in cats we are currently using aspirin given every other day or twice weekly to provide pain relief. Most cats will tolerate this well but it is important to watch for any changes in appetite and to be cautious using aspirin when cats have chronic kidney disease.

There are a great number of very good pain relief medications for dogs now. It is possible to provide very good long term pain relief in dogs when it is necessary. Just like in people different dogs will respond better to one medication than another so don't give up on pain relief if the first attempt at medicating for it doesn't work well enough. There are at least four or five very good non-steroidal anti-inflammatory medications available for pain relief in dogs and usually one will help with chronic pain due to degenerative joint disease. For surgical pain dogs also have many more choices so if your dog seems to be in pain after surgery despite the use of pain relievers let your vet know. It is very likely that your vet can supply additional or alternative pain relief medications.

Too many medications to know them all:

There are so many medications available to veterinarians at this time that it is probably safe to say that no veterinarian is familiar with all of them. Veterinarians get medications from two sources, distributors who carry many brands and directly from pharmaceutical manufacturers. Some manufacturers only sell directly to vets and if a product from one of these companies is available but no one is coming to the vet's practice to discuss the medication it may be months or even years before the veterinarian becomes aware of the medication.

Veterinarians are allowed to write prescriptions for human medications even though we can’t order them directly from distributors or manufacturers in many instances. This means that a very large number of medications are available that might help certain pets but which for which clinical trials or random clinical trials have never been run in pets. This doesn't usually stop veterinarians from prescribing these medications if they really feel they may be beneficial. It is fairly important to recognize that while there really is a potential for great benefit in having the option to prescribe human medications there is also potential for great harm, as well. If you would ask your own doctor for some evidence that proper drug studies have been done before using a medication you might consider asking your vet the same thing. There are lots of times when the potential benefit truly outweighs the potential risk but I wouldn't hop on the bandwagon to get the latest and greatest medication when a well proven old standby is readily available.

Distributors who carry many brands also carry many rumors from clinic to clinic. I am always amused by anecdotal stories of how "Dr. X" is obtaining great success with medication "Y" from my drug distributors. It isn't that I totally distrust their information, I just recognize that this doesn't come close the standard of evidence that I would like to have. I know that I am sometimes guilty of giving testimonials for medications, too. It is just human nature. It isn't good science, though. All of us get caught up in the search for the next miracle drug at times. I can't even begin to count the number of times I have tried medications for chronic skin diseases that I just knew from "the buzz" were going to cure all my difficult to treat skin disease patients. So far, some of these medications have proven useful in some patients but I'm a long ways from curing all of the chronic skin disease in my practice and I suspect that is true for all vets.

Too many medications to stock them all:

In some cases vets are aware of medications but have difficulty obtaining it at a reasonable price due to the manufacturer's policies. We are a very small clinic and it is frustrating to us when a pharmaceutical company wants us to order minimum quantities for medications we have limited use for. It is also hard to stock medications that will not be used up within a reasonable period of time. We probably discard between $2000 and $3000 worth of outdated medications yearly at our clinic. For these reasons, there will be situations in which you may be aware of a medication that has been recommended for a condition your pet has and not be able to get it from your veterinarian, even if he or she is aware of the medication.

There are several ways around this problem. Some vets use a pharmacy warehousing service like VetCentric, which stocks a wide variety of veterinary drugs but allows veterinarians to prescribe them at a cost set by the veterinarian. This allows the vet access to seldom used medications without loss of the income associated with them going out of date or for writing prescriptions instead of dispensing medications. For drugs that are used in human medicine as well as veterinary medicine it is possible for your vet to write prescriptions for the medication that can be taken to a pharmacy to be filled. Sometimes equivalent human drugs are more expensive than the veterinary version of the drug but usually there isn't any difference in price for generically available medications.

Veterinarians will sometimes dispense their second or third choice in medications simply because they have the medication on hand and do not have the drug that would otherwise have been their choice. If it seems clear that your pet might be better off on another medication ask your vet if it is possible to write a prescription for it or to get the medication from a company such as Vetcentric (tm). It is usually possible to find a way to obtain a medication when it is important to do so, even if it is one that it is impractical to keep in stock.

Splitting medications

It is less expensive to buy larger sizes of many medications and to split the medication than to buy the correct dosage size in many cases. Sometimes there is almost no difference in price between 5mg and 10mg methimazole, for instance. If a cat needs 5mg of the medication twice a day it is less expensive to buy the 10mg size and to split the tablets. This works for a number of different medications. In other cases it is possible to choose between twice daily dosing and three times a day dosing to get to recommended medication levels and it may be less expensive to give the medications three times a day in some cases. An example of this would be administering cephalexin to a 75 lbs. dog. If the medication is given at the correct dosage twice daily the dog would need to have one 500mg capsule and one 250mg capsule twice a day. Since the capsules are not too much different in price it is about 25% less expensive to give 500mg of cephalexin three times a day, which is an acceptable way to medicate. Veterinarians know that client compliance decreases with each additional time a medication must be given during the day and may be reluctant to dispense three times a day medications but if you know you will give the capsules it is reasonable to use the less expensive approach.

There are medications that can not be split. The manufacture does not recommend splitting Heartgard Chewable (tm) tablets as it is not certain that the active ingredient (ivermectin) is evenly distributed in the chewable tablet. Omeprazole ( Prilosec tm) should not be split as it is important that it retain its film coating. This is true for a number of medications so it is always best to consult with your vet prior to splitting medications. Most vets will willingly prescribe medications that can be split when it is more economical for their clients so you can generally trust your vet to be straight with you about which medications can and can't be divided.

Some of the products used by veterinarians are approved by the EPA or USDA rather than the FDA. The regulations governing these products are different than those of the FDA. Where it is perfectly legal for your veterinarian to recommend splitting an FDA approved medication it is actually illegal to use EPA approved products "in a manner inconsistent with the labeling". This means that even though it seems to make perfect sense that an 88 lb. dose of Frontline Topspot (tm) could be even split between two 44 lbs. dogs, your vet can't advise doing this as it is illegal to do so. I know several vets who appear not to recognize that there is a difference in dispensing laws between FDA approved and EPA approved products so if your vet advised splitting the dosing of topical flea control products it is possible he or she just isn't aware that this is not something they can legally recommend to you.

Medication Form Matters

It may surprise you but the form a medication comes in can have a big bearing on the cost of the medication. To give you one example, there is enough Frontline Spray (tm) in a 250ml bottle to treat a 16 pound cat ten times. The bottle of Frontline Spray costs about the same as three tubes of Frontline Topspot (tm) topical applications. It is therefore three times as expensive to use Frontline Topspot for cats than it is to use Frontline Spray, even though they both contain the same active ingredient. Oddly enough, it is usually less expensive to treat large dogs with the Topspot than with the spray. For small dogs and cats, though, Frontline Spray is a bargain compared to Topspot.

Liquid versions of antibiotics and several other medications routinely cost twice as much as the pill forms of the same medications. While it may be a little more difficult to give a cat a pill than it is to give a liquid medication it can save money. There is usually no advantage to liquid medications over pills if both versions of the medication are available and you can verify that the medication is actually successfully administered.

Injectable medications are usually the most expensive form of a medication. Lots of times my clients really want an injection of an antibiotic or other drug for their pet, thinking that it will really make a big difference. For a wide range of drugs the difference between reaching effective drug levels between using the injectable form and the oral form of a medication is less than an hour. There really isn't much reason to give an injection for a condition that isn't threatening the pet's life when there is this little difference between the time it takes to reach effective blood levels. There are some exceptions where effective blood levels can be achieved much more rapidly by injection and there are also times when the injection is actually less expensive to use than other forms of a medication, although this is unusual. One example of a time when effective blood levels are achieved much more rapidly when using an injection involves the use of phenobarbital injection to treat a seizuring pet. By giving the injection effective blood levels are achieved almost immediately but it takes several weeks to obtain effective blood levels of phenobarbital by oral administration. Some of the pain relieving medications seem to work better when injected prior to surgery to ensure that blood levels are adequate when the pet wakes up from the procedure.

If you have a choice between the forms of a medication and cost is a significant factor ask your vet which dosing form is less expensive and get him or her to show you how to successfully administer the form of the medication you choose.

Drug Reactions

Reactions to medications and vaccinations occur more frequently than many veterinarians think. Reactions to medications and vaccinations occur less commonly than many veterinary clients think. The reason for both misconceptions is probably perspective. Veterinarians use medications all the time and most of the time there are no significant side effects that are not unexpected. When reactions do occur it isn't unusual for the veterinarian to be unaware of them because the client doesn't let them know or because of other communication problems. This makes the mindset of vets move towards believing that reactions are very rare events. Veterinary clients, on the other hand, tend to think that anything that goes wrong after administration of a medication or vaccination is due to the medication or vaccination. In reality, coincidence is a very common reason for events that are unrelated to the drug or vaccine to be blamed on it. People have a very hard time ignoring coincidental events because our survival instincts demand that we recognize links between things that happen to us and bad events. Our species wouldn't have survived very long if we couldn't recognize that eating poisonous foods made us ill or caused death and therefore it was necessary to avoid that potential food source, for instance.

The reluctance of veterinarians to recognize when a drug reaction has occurred can be partially remedied by continued reporting of potential drug reactions from clients. It might seem to be just coincidence the first time that liver disease occurs after starting a non-steroidal anti-inflammatory medication but if five or six clients report the same thing it becomes obvious that a pattern is developing. Let your vet know when you suspect that a drug reaction has occurred. Make sure that your vet reports the reaction to the drug company if it seems to be serious. This reporting is the only way to recognize unusual drug reactions since they may occur infrequently enough that only persistent reporting of drug reactions will cause them to be recognized. Vaccine reactions can occur for at least two or three weeks after vaccine administration so don't be put off by a veterinarian or member of veterinary staff who believes that a reaction is unlikely because a vaccine was given several days previously. Likewise, drug reactions can occur even after a pet has tolerated a drug for a very long time previously. Don't discount the possibility of a drug reaction just because a pet has been on the medication for a long time.

If your vet is certain, or nearly certain, that the cause of a suspected reaction is something other than the drug or vaccine that has been administered there is a very good chance that he or she is right. Some drugs are very unlikely to cause certain symptoms and if your pet has those symptoms it is more likely that something other than that particular drug caused them. Other drugs have long lists of possible symptoms but rarely seem to cause side effects in practice. For this group of drugs it is harder to be certain they are not the cause of a problem but your vet may really believe that it is more beneficial to look for other causes based on past experiences with the medication. To a big extent you have to trust your vet's judgment but when you just aren't sure ask that he or she report the possible reaction to the drug company, anyway. Perhaps it will turn out to be one of the very rare reactions that only gets discovered because people finally report enough cases to make a connection between the drug and the reaction.