Liquid Trilostane for Dogs: What Owners Need to Know
Trilostane is an active substance widely used in the veterinary management of naturally occurring hyperadrenocorticism, commonly known as Cushing's disease, in dogs.
Historically, many owners have been familiar with trilostane supplied in fixed-strength oral formulations. Authorised liquid oral suspensions containing trilostane are also now available in Great Britain, providing veterinary surgeons with another formulation option when prescribing treatment.
The underlying active substance is the same, but a liquid formulation changes how the prescribed dose is measured and administered.
What Is Liquid Trilostane?
Liquid trilostane is an oral suspension containing the active substance trilostane.
Authorised 50 mg/ml trilostane oral suspensions are currently available for dogs in Great Britain. They are prescription-only veterinary medicines authorised for the treatment of pituitary-dependent and adrenal-dependent hyperadrenocorticism.
Because the medicine is supplied as a liquid, the prescribed dose is measured as a volume using an appropriate oral dosing syringe rather than being given as a fixed-strength capsule or tablet.
Why Might a Vet Choose a Liquid Formulation?
The choice between a liquid and solid oral formulation depends on the individual dog and the prescribing veterinary surgeon's judgement.
Individual Dose Measurement
A liquid allows the prescribed quantity of trilostane to be measured as a volume, which can be useful where the veterinary surgeon wants a dose that does not correspond neatly to a fixed-strength solid formulation.
Smaller Dogs
For some smaller dogs, measuring an oral suspension may provide a practical way of administering the exact quantity prescribed by the veterinary surgeon.
Dose Adjustment
Dogs with Cushing's disease require monitoring and treatment may be adjusted according to clinical response. A liquid formulation gives the prescriber another way of delivering the required dose.
Administration Preference
Some owners and dogs may find a measured liquid easier to administer than a solid oral formulation, while others may prefer tablets or capsules.
Is Liquid Trilostane Stronger Than Capsules?
Not inherently.
The important factor is the amount of trilostane prescribed, rather than whether it is supplied as a liquid, capsule or tablet.
Different authorised formulations may contain different concentrations or strengths, so the prescribed quantity should always be followed exactly.
The prescribed dose and volume depend on the concentration of the individual medicine. Changing formulation without veterinary guidance can result in an incorrect dose.
How Is Liquid Trilostane Given?
Current authorised trilostane oral suspensions are given by mouth using a measuring syringe.
The product information for authorised formulations instructs owners to shake the suspension before use and administer it at feeding time. Exact instructions should always be taken from the medicine supplied and from the prescribing veterinary surgeon.
Using the correct oral syringe is important because relatively small differences in volume can alter the amount of trilostane administered.
Why Does Trilostane Need Monitoring?
Trilostane reduces adrenal steroid production. The treatment therefore needs to control excessive cortisol without suppressing adrenal function too far.
Monitoring may involve:
- Assessment of thirst and urination
- Appetite and activity
- Body weight
- Electrolyte measurements
- Kidney and liver-related blood parameters
- Assessment of adrenal function where appropriate
Monitoring protocols vary between individual dogs and should follow the veterinary surgeon's instructions and the authorised product information.
Does a Liquid Formulation Change the Monitoring?
No. The need for monitoring relates primarily to the effects of trilostane and the dog's underlying Cushing's disease rather than simply whether the medicine is supplied as a liquid or solid formulation.
A dog changing formulation may still require reassessment because the prescribing veterinary surgeon needs to confirm that the new dose and administration method are providing appropriate control.
What Happens if the Dose Changes?
Dogs with Cushing's disease do not all require the same amount of trilostane, and treatment requirements may change over time.
Dose changes should only be made by the prescribing veterinary surgeon following appropriate clinical assessment and monitoring.
One practical feature of an oral suspension is that the prescribed volume can be altered without necessarily changing to a different fixed-strength tablet or capsule.
That does not mean owners should adjust the amount themselves. Even apparently small dose changes may be clinically important.
How Should Liquid Trilostane Be Stored?
Storage instructions vary according to the authorised medicine supplied, so owners should follow the label and package leaflet accompanying their prescription.
Current authorised 50 mg/ml trilostane oral suspensions have an in-use shelf life after opening, making it important to record when the bottle was first opened and discard it according to the manufacturer's instructions.
What Should Owners Watch for During Treatment?
Owners should contact their veterinary practice if a dog receiving trilostane develops concerning signs such as:
- Loss of appetite
- Vomiting
- Diarrhoea
- Marked lethargy
- Weakness
- Collapse
- Any sudden or significant deterioration
These signs can have many causes, but dogs receiving treatment that affects adrenal hormone production require prompt veterinary assessment if they become unwell.
Liquid Trilostane vs Solid Trilostane
Liquid Formulation
- Dose measured as a volume
- Administered with an oral syringe
- Allows measurement of intermediate prescribed quantities
- Requires shaking before administration
Solid Formulation
- Supplied in fixed strengths
- Simple unit-based administration
- No volume measurement required
- May suit dogs that readily take tablets or capsules
Neither format is automatically better for every patient. The most appropriate formulation is the one that allows the prescribing veterinary surgeon to provide an appropriate treatment plan for the individual dog.
Frequently Asked Questions
Is liquid trilostane licensed for dogs in the UK?
Yes. Authorised trilostane oral suspension formulations are available for dogs in Great Britain for the treatment of naturally occurring hyperadrenocorticism.
Is liquid trilostane the same active ingredient as other trilostane formulations?
Yes. The active substance is trilostane. However, different veterinary medicines may have different concentrations, formulations and administration instructions.
Can I change my dog from capsules to liquid trilostane?
Only on the advice of your veterinary surgeon. The prescribed amount needs to be converted appropriately for the concentration of the medicine being supplied.
Does liquid trilostane need to be shaken?
Authorised oral suspension formulations instruct users to shake the medicine before use. Always follow the instructions supplied with the particular medicine prescribed for your dog.
Does my dog still need blood tests?
Yes. Appropriate monitoring remains an important part of trilostane treatment regardless of the formulation being used.