Compounded drugs and clinical practice (Proceedings)

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Compounded drugs and clinical practice (Proceedings)

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Nov 01, 2009

Compounded drug formulation for use in equine clinical practice has at least two clearly ethical appeals, one contentious issue, and one non ethical practice.

1. Drugs that are not available in commercial formulations useful in horses can be compounded for better ease of administration and clinically effective applications. Also, drugs without Food and Drug Administration (FDA) approval, human or otherwise, can be formulated. This is the essential function that pharmacy compounding fulfills, because there is a large need for medications in equine practice relative to the small number of drugs FDA approved for horses.

2. Compounding of drugs that have been approved for horses, but have been withdrawn by the sponsor is fair game for compounding pharmacies (e.g., oral flunixin meglumine powders, or dipyrone injectable). Again this is an essential function fulfilled by compounding pharmacies.

3. Compounded drugs are often far less expensive than FDA approved formulations for other species, especially those approved for human beings. Compounding of these formulations is a contentious issue. By the letter of the guide this is inappropriate compounding. However, expense of products approved for human beings can preclude treatment. It is the author's opinion that if the veterinarian and the owner are aware of issues in using compounded drugs, this is a rational use for them.

4. Compounded drugs that mimic FDA approved drugs are often far less expensive than FDA approved formulations for horses. This is the disturbing form of compounding that has a severe negative impact on drug development and equine practice. In addition, this is an unethical practice as defined by most pharmacy boards and good compounding practice. As an example, using compounded omeprazole, clenbuterol (both for oral use), or flunixin meglumine, (for iv use) in horses is not advisable or appropriate on several levels. Quality of clinical medicine, negative impact on equine drug development, and client expectations are just a few issues. The quality of the compounded medication cannot be guaranteed. Hence, it is reasonable to assume that this increases your liability, and reduces the quality of care delivered. Compounding of these drugs is considered unethical by the AVMA.

Veterinary compounded drug quality is greatly unregulated in most states. Essentially quality is dictated by the ethical and knowledge bounds of your pharmacist. Clearly an essential part of rational therapeutic drug use is the knowledge of the quality, strength (concentration), purity and availability of the molecule in the formulation you intend to administer. In this respect, when a compounded drug is prescribed, veterinarians should have complete knowledge of the compounding pharmacy selected for this process, since the veterinarian bears a portion of the responsibility for the use of these formulations. In addition, veterinarians must decide when quality is outweighed by cost. In other words, when is a clinical decision to use a compounded medication worth the risk of ineffectiveness or adverse responses in the patient and to the client.

It is judicious for veterinary practitioners to assume that they are ultimately responsible for the use of a compounded product. This more clearly defines the seriousness of using compounded formulations. Clearly, it behooves the veterinary practitioner to be sure that the compounding pharmacy is following appropriate compounding pharmacy laws and guides.

Regulation of compounded drugs

Knowledge of a drug's strength and availability to a patient is essential to achieving a positive effect. If practitioners choose to compound, or to prescribe compounded medications prepared by a pharmacist, they may be accepting the responsibility for the formulation's effectiveness, safety and composition. FDA approved drugs are consistently formulated to specification. Assurance of a formulation's composition or its availability to the patient is less certain when veterinarians prescribe compounded medications. Therefore, the veterinarian must collect specific information to aid in the identification and choice of a quality compounding pharmacy. However, remember that even with compounding pharmacies with high quality standards, there is little scientific information for the pharmacologic characteristics of compounded formulations in animals. Some pharmacies have incorporated analytical techniques (e.g., HPLC), but this practice is not widespread.

Federal and state compounding regulations and guidelines do little to monitor quality of product. Compounding of animal drugs is regulated principally by the Food and Drug Association (FDA) at the federal level and pharmacy boards at the state level. FDA regulates compounding through the Federal Food Drug and Cosmetic Act. Federal regulations regarding compounding are located in Section 21 of the Code of Federal Regulations, Part 530 entitled "Extralabel Drug Use in Animals." Also, FDA's policy regarding compounding can be found in the Compliance Policy Guide 608.400 entitled "Compounding of Drugs for Use in Animals." Veterinarians are encouraged to read these documents, as well as the pharmacy board laws and guides in their respective states, to get a more complete understanding of the legal requirements. However, even with federal and state regulatory oversight there can be quality issues associated with compounded products.

State pharmacy boards perform annual or biannual inspections and are effective at responding to complaints. If you believe that a pharmacy is performing in an unethical manner (e.g., compounding for lay-persons, not providing the drug in the prescribed concentration, etc.), then you should to file a report to your state pharmacy board. ( http://www.avma.org/ "Addressing, prescribing and dispensing in your practice")

Provisions in federal and state laws also apply to veterinarians, if they find themselves in situations where the only choice for treatment is a compounded medication. Use of compounded medications is bound legally and ethically by several stipulations that include, but are not limited to, the development of a veterinarian-client-patient relationship, prescription drug dispensing restrictions, and use in the treatment of disease or to improve welfare of the animal. In addition, there should be no FDA commercially available approved product in a suitable dosage form to treat the condition (e.g. a need for an IV formulation, when only tablets are approved).

Economics

Cost versus the use of FDA approved formulations

Compounding of formulations for routes that are the subject of a New Animal Drug Approval (NADA, FDA veterinary approval, see http://www.fda.gov/cvm/greenbook/) for use in horses or food animal species is not appropriate according to good compounding practice guidelines in almost every state. Since the ethical nature and compounding knowledge of the pharmacist is essential to the quality of compounded drugs, then it could be assumed, but not guaranteed, that pharmacies that provide this service may be suspect in terms of providing quality product. However, the cost of some formulations that are the subject of a New Drug Approval (NDA) for use in persons or small animals may preclude the use of these drugs for veterinary practice. In this case compounding may be rational and clearly arguable.