Soliphen 15 mg Tablet for Dogs

The decision to start antiepileptic drug therapy with phenobarbital should be evaluated
for each individual case and depends on number, frequency, duration and severity of
seizures in dogs.
To achieve successful therapy, administration of tablets should occur at the same
time(s) each day and should be co-ordinated with feeding times in a consistent manner.
Withdrawal or transition from other types of antiepileptic therapy should be made
gradually to avoid precipitating an increase in the frequency of seizures.
Some dogs are free of epileptic seizures during the treatment, but some dogs show only
a seizure reduction, and some dogs are considered to be non-responders.

Amended pages: August 2025
AN: 01034/2025Page 2 of 8

i. Special precautions for use in animals
Caution is recommended in animals with:
- impaired hepatic and renal function
- hypovolemia, anaemia and
- cardiac or respiratory dysfunction
The chance of hepatotoxic side effects can be diminished or delayed using an
effective dose that is as low as possible. Monitoring of hepatic parameters is
recommended in case of a prolonged therapy.
It is recommended to assess the clinical pathology of the patient 2-3 weeks after
start of treatment and afterwards every 4-6 months, e. g. measurement of hepatic
enzymes and serum bile acids. It is important to know that the effects of hypoxia etc.
do cause increased levels of hepatic enzymes after a seizure.
Phenobarbital may increase the activity of serum alkaline phosphatase and
transaminases. These may demonstrate non-pathological changes but could also
represent hepatotoxicity. Therefore, in the case of suspected hepatotoxicity, liver
function tests are recommended.
Treating dogs with phenobarbital may lower TT4 or FT4 serum levels, however this may
not be an indication of hypothyroidism. Treatment with thyroid hormone replacement
should only be started if there are clinical signs of the disease.
In stabilised epileptic patients, it is not recommended to switch between
phenobarbital formulations. However, if this cannot be avoided then additional
caution should be taken. This includes more frequent plasma concentration sampling
to ensure that therapeutic levels are maintained. Monitoring for increased side
effects and for hepatic dysfunction should be conducted more regularly until
stabilisation is confirmed.
A wide therapeutic range of phenobarbital concentration in the serum of 15 mg/l to
40 mg/l is often stated. Optimal seizure control is achieved in most dogs with a
serum phenobarbital concentration of between 25−30 mg/l. High serum
concentrations of more than 35 mg/l should be avoided due to increased risk of
hepatotoxicity. Below these ranges, in dogs with good seizure control, no change of
dose may be necessary, as the concentration may be sufficient for that individual.
As a general guide, serum phenobarbital concentration should be the lowest to
achieve a decrease in seizure frequency of greater than 50%, or absence of seizures
where possible, without intolerable side effects.
ii
medicinal product to animals
People with known hypersensitivity to phenobarbital or other barbiturates should
avoid contact with this veterinary medicinal product.
It is advisable to wear disposable gloves when handling the product, to reduce skin
contact.

Amended pages: August 2025
AN: 01034/2025Page 3 of 8Phenobarbital is a teratogen and developmental neurotoxicant and transfers to
breast milk.
The product should not be administered by pregnant women, women intending to
become pregnant or whose pregnancy status is unknown, as well as lactating
women.
Ingestion of Phenobarbital can cause neurotoxicity which may prove fatal. Take
utmost care that children do not come into any contact with the product. Children
are particularly at risk of intoxication. To prevent accidental ingestion of tablets, the
container should be closed immediately after withdrawing the required number of
tablets for one administration. Part tablets should be placed back into the container
and used at the next administration, as even part tablets pose a health risk to small
children if ingested. The container should be stored in a safe place out of the sight
and reach of children.
In case of accidental ingestion, seek medical advice immediately and show the
package leaflet or the label to the physician. If possible, the physician should be
informed about the time and amount of ingestion, as this information may help to
ensure that appropriate treatment is given.
Wash hands after use.