CPD ACCREDITED ARTICLE
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When the GIT of man is compared to animals, there
are major difference that can influence absorption
between the species. These difference may be ana-
tomical in that there are different structure of the GIT;
there may be difference in transit times; difference in
content and thus non-specific binding; differences in
bile salts; differences in pH amongst the different ar-
eas; differences in GIT bacterial content and/or spe-
cies; differences in liver metabolic capacity; and most
importantly differences in the transport proteins in the
intestinal wall. The latter is also a major reason why
veterinary drugs differ so much between species.
To illustrate the process, the innovator veterinary for-
mulation of amoxycillin-clavulanate and Ran-Clav®
(Ranbaxy) were compared at the same dose and the
same route in the same six Beagles (in a cross-over
study undertaken by myself). (Figure 4) The result for
amoxycillin phase of the study showed a marked dif-
ference in absorptive profile between the two formu-
lations. While the small sample size did result in signif-
icant variability in both groups, this was much more
substantial (>80%) in the Ran-Clav® group. This study
illustrates the point that the non-veterinary formula-
tion could not only differ in the extent of absorption,
but more importantly could result in large intra-sub-
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Another important scenario that comes up in South
Africa is the cost of the medication. Under some con-
ditions veterinary medications may be more expen-
sive than their medical generics, due to lower costs
on the medical side from larger scale production. Can
one use these human generics as cheaper therapeu-
tic options? Firstly legally, the onus is on the treating
veterinarian to let the owner know that there is a vet-
erinary formulation and give them the option. The
reason for this, is that the medical product has been
tested in only people and thus the veterinary profile
may be unknown i.e. it may be possible that the drug
has different profiles in the veterinary patient than in
people.
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1000
500
0
0
2
4
6
8
10
12
14
Time (h)
Figure 4: Average plasma concentration versus time profile for
amoxycillin for a veterinary (R) and non-veterinary (T) amoxy-
cillin formulation tested in the same group of six dogs in a 2x2
cross over study.
ject variability which could mean completely inferior
treatment in some individuals. This effect is addition
to being potential dangerous, is also generally un-
known until tested.
Conclusion
Drug regulation science, is a highly complex science
that is focused on allowing the treating veterinarian
the best chance of getting therapeutic success in a
patient with the least chance of formulation failure.
This science extends to both innovator and generic
formulations, but only so far as to the species and in-
dication for which the product has been tested. As
such, when using a non-veterinary formulation, care
should be practiced, as therapeutic success are affect-
ed by a number of unknown variables such as added
exipients and exact structure of the active chemical/
ingredient.
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linevets CPD facility for Vet360 Subscribers
Category Use Benefits Dangers Liabilities
Innovator Vet Medi-
cine/Stock Remedy Registered Use Proven safety, quality
and efficacy Poor storage can change product
safety If used and stored as per instruc-
tions: Falls to the manufacturer
Generic Vet Medi-
cines/Stock Remedies Registered Use Proven safety, quality
and efficacy Poor storage can change product
safety If used and stored as per instruc-
tions: Falls to the manufacturer
Stock Remedies: Vet
Med (innovator or ge-
neric) used extralabel Used for non-regis-
tered purpose in the
intended species Proven quality. Safety
knoen in target species
if used at the recom-
mended dose Unknown efficacy when used for a
new indication and potentially safety
concerns when used at a different
dose Vet liable for extralabel use, since
use is in the intended species i.e.
species saftety usually known
Stock Remedies: Vet
Med (innovator or ge-
neric) used extralabel Used for non-regis-
tered purposes in a
non-indicated species Quality of the product
proven Unknown efficacy as used for a new
indication, and unknown safety con-
cerns as used in untested species Vet liable for extralabel use. Risk
increases as species safety usual-
ly unknown
Human Meds Non-registered use Quality of the product
proven Unknown efficacy and safety Vet liable for extralabel use. Risks
are the same as use of a veter-
inary medicine in non-indicated
species
Compound Meds Non-registered prod-
uct Patient specific treat-
ment option when no
registered product is
available Unknown safety, efficacy and quality Vet liable for use. Greater risk
than extrlabel use, since quality,
safety and efficacy unknown
Table 2: Indication of how personal liability increases as different categories of medicines are used
vet360
Issue 03 | JUNE 2017 | 20