EQUIOXX
Equioxx is a highly COX-2 selective NSAID for use in horses suffering from osteoarthritis
Relative COX selectivity of different equine NSAIDs:
Active
Brand names
Selectivity
ingredient
Firocoxib
EQUIOXX
643 :1
Phenylbutazone
Equipalazone, Pro-Dynam
1.6 :1
Suxibuzone
Danilon
1.6 :1
Flunixin
Finadye, Binixin, Meflosyl
0.3 :1
Meloxicam
Metacam
3.8 :1
Vedaprofen
Quadrisol
8 :1
Carprofen
Rimadyl
1.6 :1
Ketoprofen
Ketofen
~1
Classification
SELECTIVE
Non-selective
Non-selective
Non-selective
Preferential
Preferential
Non-selective
Non-selective
Significance of being highly selective:
Completely spares COX-1 at normal doses
COX enzymes:
The function of the COX enzymes is the production of various prostaglandins, many of
which are needed for normal physiological function
COX-1
Responsible for production of “good”
prostaglandins, needed for normal
function, such as protection stomach and
blood clotting
Examples- PGE2 in stomach, thromboxane
in platelets
COX-2
Responsible for production of “bad”
prostaglandins which cause pain and
inflammation
Example- PGE2 in joints with OA
NSAID side effects:
Gastrointestinal- stomach ulcers and damage to colon (particularly ‘bute)
Renal failure
Severe cases- death
Benefits of sparing COX-1
No inhibition of beneficial prostaglandins, so less likely to get GI side effects, even at
high doses
Pharmacokinetics
After oral dose:
- appears in plasma within 30 mins
- peak plasma at 4 hrs
- half-life= ~30hrs
- 7 doses to reach “steady state” in plasma (but will start working before this)
- Good tissue penetration
Data sheet summary
Licensed claim
Alleviation of pain and inflammation associated with osteoarthritis and reduction of
associated lameness in horses.
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Dose
0.1mg/kg once daily for 14 days
Minimum age- 10 weeks
Adverse effects:
Lesions (erosion/ulceration) of the oral mucosa and of the skin around the mouth
may occasionally be observed in treated animals. Typically, these lesions are mild
and resolve without treatment, but oral lesions may be associated with salivation
and labial and tongue oedema.
Contraindications:
Do not use in animals suffering from gastrointestinal disorders and haemorrhage,
impaired hepatic, cardiac or renal function and bleeding disorders.
Do not use in breeding, pregnant or lactating animals.
Do not use concomitantly with corticosteroids or other NSAIDs.
Use in pregnancy?- NO, not licensed
Withdrawal period:
26 days for meat and milk
Racing- NO OFFICIAL DETECTION TIME YET- recommend 30 days
TRIAL SUMMARIES
Dose determination study
 4 groups of 16 horses
 Treated at 0.05mg/kg. 0.1mg/kg and 0.25mg/kg. Untreated control group
 Treated for 14 days
 Assessed by lameness score and force plate analysis
Key outcomes:
 Similar results for 0.1 and 0.25mg/kg groups
 Started working immediately- significant improvement seen within several
hours
EQUIOXX versus Bute field trial
 127 horses in EQUIOXX group, 126 horses in bute group
 Treated for 14 days
 Doses: 0.1mg/kg for Equioxx, 4.4mg/kg for bute (higher than usual dose in UK)
 Assessed by:
- lameness score
- pain on manipulation of joint
- joint swelling (subjective and objective)
- range of motion
Key outcomes:
 similar proportion of horses improved on lameness scores
 significantly better results for Equioxx for joint swelling, range of
motion and pain on manipulation
Significance:
Equioxx possibly more effective at reducing inflammation in joint
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STRIDE Trial
 very large trial (429 horses)
 various ages (2-33) and weight (190-900kgs)
 0.1mg/kg for 14 days
 Assessed by vet lameness scoring and owner assessment
Key outcomes:
 Good improvement in lameness grades after 14 days (25% with no
lameness at all)
 Owner scores- improved over time, highlighting benefits of giving full
treatment course
COXIB issues in humans
 Vioxx was withdrawn from market in 2004, ndue to increased incidence of heart
attack/stroke in human patients
 Due to underlying atherosclerosis
 Atherosclerosis is not a problem in veterinary medicine, so being highly selective
for COX-2 is not an issue
Presentations
 Injectable for IV use, low dose volume (1ml/225kgs)
 Oral paste syringe- one syringe treats up to 600kg horse, 100kg increments
Injectable dose rates
Drug
Equioxx
Metacam
Equipalazone
Finadyne
Dose (mls/kg)
1ml/225kgs
1ml/45kgs
1ml/33kgs
1ml/45kgs
Volume for 600kg horse
2.67mls
13.2mls
18mls
13.2mls
COLIC Paper summary
 3 groups of 6 horses- saline control group, Equioxx group and flunixin group
 Damage induced to small intestine by cutting off blood supply for two hours
 Impact on gut healing assessed
 Behavioural pain scoring also done to evaluate pain relief
Key outcomes
 Pain scores similar in Equioxx and flunxin groups
 Flunixin group had slower gut healing than Equioxx or control group
Significance:
Equioxx does not impact on healing of the small intestine and was an
effective analgesic
Laminitis paper summary
 Not a specific study assessing efficacy or safety in laminitis
 Commentary by KOL on choosing an NSAID for laminitis
 Quote:
“For horses being treated for laminitis and having significant risk for intestinal or
renal injury from prolonged NSAID use, firocoxib could be a medically sound
selection and, in a study of naturally occurring equine osteoarthritis, pain
reduction with firocoxib was comparable to phenylbutazone”
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Use in foals
 Licensed from 10 weeks
 Anecdotal data from USA and some safety trials in foals (from 36hrs old) suggest
that dose of 0.1mg/kg is well tolerated
Oral ulcers
 Ulcers were present in all horses prior to treatment in the safety studies (including
the negative control group)
 In the overdose groups (3 times and 5 times overdose), the incidence was slightly
higher than in the control group by the end of the study, hence the label warning
 In the field trials, out of approximately 600 horses treated with Equioxx, only one
horse had mild transient hypersalivation and lip swelling for one day
 A review of the pharmacovigilance data from the US shows that they did not have
any reports of oral ulcers during 2010. In conclusion, a very uncommon and mild
potential adverse effect
List prices
EQUIOXX Injection 25ml = £66.81
EQUIOXX Paste = £7.19
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