Privileges versus rights of the use of medicines by the veterinarian
J.G du Toit
Veterinarians are in the privileged position of being able to dispense and compound medicines for their patients. These functions are typically performed by pharmacists.
The primary reasons for this are that most pharmacists do not stock medicines for animals due to the low demand, and in rural communities, pharmacies may not be easily accessible for farmers.
This article uses the wildlife veterinarian as an example to explain the challenges veterinarians may encounter in their practice.
The reasons for using pharmaceutical products to capture wild animals are.
• To examine and treat sick and injured animals, or those that have been caught in snares or traps.
• To remove aggressive individuals from a captured group.
• To select specific animals from a group for breeding purposes.
• To mark animals and to fit them with telemetry collars for ecological and other studies.
• To capture and retrieve animals that have escaped from a wildlife ranch or reserve.
• To collect blood for disease studies and surveillance, such as for foot-and-mouth disease surveys.
The principles of selecting the drugs and dosages are as follows:
• Preference for a wide therapeutic index (the ratio of the effective to the lethal dose) for safer use on animals.
• Rapid effect to increase the chances of finding darted animals.
• Minimal side-effects such as excitement, muscle tremors, respiratory and circulatory depression, changes in body temperature, salivation and bloat.
• Effective immobilisation of the animal.
• Small volume is required to fit in a 3 to 5 cc dart.
• Availability of a reversal agent to ensure the animal’s survival after capture.
Compounding and manufacturing medication for wildlife.
“compounding” means to prepare, mix, combine, package, and/or label a non-registered medicine(s), or to mix or combine a registered medicine with a non-registered medicine for dispensing as a result of a prescription for an individual patient, as defined by Rule 1, by a pharmacist or a veterinarian authorised in terms of the Medicines Act. (Def from Veterinary Rules)
To “compound” means to prepare, mix, combine, package and label a medicine- (a) by a pharmacist, pharmacist intern or pharmacist’s assistant practising in accordance with the Pharmacy Act for – (i) an individual patient; or (ii) an animal as a result of a prescription issued by a veterinarian practising in accordance with the Veterinary and Para -Veterinary Professions Act, 1982 (Act No.19 of 1982); or (b) for dispensing as a result of a prescription for a patient by a person licensed in terms of section 22C(1)(a) of the Act and practising in accordance with the relevant scope of practice; (Amendment Medicines Act 101 (Government gazette 25 August 2017 No 41064).
Manufacturing involves the production, preparation, propagation, conversion, and/or processing of a drug or device, either directly or indirectly, through extraction from substances of natural origin or chemical or biological synthesis. The term includes any packaging or repackaging of the substance(s), relabelling its container, and promoting and marketing such drugs or devices. It also includes preparing and promoting commercially available products from bulk compounds for resale by pharmacies, practitioners, or qualified persons.
Game capture drugs for wildlife are used to capture healthy animals, capture, and treat sick animals or used to reduce stress and mortalities in wildlife. Compounding allows veterinarians to use available human medical drugs, making it possible to capture wildlife with a tailor-made darting “cocktail” specific to species. It also enables the use of medicines in animals that are not currently available in South Africa, where not more than six such drugs are registered for wildlife use.
Compounding drugs allows for easier dosing with a dilution of a concentrated product in small animals, which would otherwise be impossible. Only a small volume of a concentrated drug is necessary to fill a dart. For example, 5 mg of etorphine and 150 mg of azaperone will fill a 2-cc dart. Compounding is essential when an entire herd must be tranquillised. The packaging in 1 cc ampules of medicines such as Serenace makes it time-consuming to load syringes when injecting a large group of captured animals, while the compounded product Haloperidol is available in 20 cc bottles. Wildlife veterinarians use compounded medicines daily, with well-established drug dosages, obtaining compounded medicines from a specific pharmacy with which they have a long-standing relationship.
Compounded drugs have a legal shelf life of only 30 days. Because wildlife capture operations depend on environmental factors such as high temperatures, cold fronts and rain, a compounded drug may have expired on paper but remain effective. Compounding a new batch will take time and is counterproductive. Since compounding is patient-specific, a compounding product must not be kept for routine dispensing.
Why is compounding of medicine necessary for wildlife?
• In the case where a medicine cannot be compounded the off-label use allows veterinarians to treat animals with available human medical drugs at an economic price. An example is the use of Trilafon instead of perphenazine. When a registered product or a product to use off-label is not available then a medicine can be compounded with a script from a veterinarian.
• It makes it possible to capture wildlife with dart “cocktails” tailored to the species.
• In small animals, it allows for easier dosing with a dilution of a concentrated product, which otherwise not be possible.
• It enables the use of medicines that are currently not available in South Africa by compounding them with active pharmaceutical ingredients that are legally available. Few game capture drugs (not more than 6) are registered for wildlife in South Africa.
• Only a small volume of a concentrated product is necessary to fill a dart. For example, 5 mg of etorphine and 150 mg azaperone will fill a 2cc dart.
• Compounding is necessary where a herd must be treated with tranquillizers. The packaging of medicine products such as Serenace in 1 cc ampules makes it time-consuming to load syringes to inject a large herd of captured animals, while the compounded product Haloperidol is available in 20 cc bottles.
• Wildlife veterinarians are using compounded medicines daily. The drug dosages are well established in the industry and veterinarians obtain their compounded medicine from a specific pharmacy with which they have a long-standing relationship.
Problems associated with compounding medicine in wildlife.
• Compounded drugs have a legal shelf life of only 30 days. Game capture operations depend on environmental factors such as high temperatures, cold fronts, rain, etc. This leads to the problem that the product has expired on paper but is still effective. Compounding a new batch will take time and is counterproductive.
• Compounding is patient-specific and therefore compounding products should not be kept for routine dispensing. The use of game capture products is exclusive for healthy animals and to reduce stress and mortalities in wildlife.
• Recently the product Yohimbine was confiscated at the Oliver Thambo airport without any publication of the reason in the Government Gazette. The reason from the South African Health Products Regulatory Authority (SAHPRA) stated that the product can be used as an aphrodisiac. This is a legal human problem that prevents a compounding pharmacy from compounding a medicine legally for veterinary use. Yohimbine and Atipamezole are used as antagonists (acting at the α-1 and α-2-adrenoreceptors found both in the central nervous system and peripherally) to Xylazine and Medetomidine. The problem is that Atipamezole reverses the alfa-2-receptors hundred per cent but not the α-1- adrenoreceptors. Yohimbine reacts slower than Atipamezole but binds to the α-1-adrenoreceptors. The combination is preferred by experienced wildlife veterinarians to prevent the recycling in animals.
Solutions
• Veterinarians must respect their privilege to dispense products to their clients, However, during the chemical poaching of rhinos, some stated that a veterinarian sold immobilising products to the private sector for more than R1 million. Such actions may lead to veterinarians losing their privilege to dispense drugs for their clients.
• To create an emergency body to react when a case such as Yohimbine happens. The body consists of;
a. Member of SAPHRA (Act 101) – permanent
b. Member of Department of Agriculture (Act 36) – permanent
c. Member of SA Veterinary Association – permanent
d. Member of Industry in dispute – not permanent
e. Representative of the private sector appointed by the industry in dispute – not permanent.