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DATASHEET
Epiphen Solution (Vétoquinol UK Limited) Epiphen Solution
Use of phenobarbitone in conjunction with primidone is not recommended as primidone is predominantly metabolised tophenobarbitone.
Presentation:
Solution containing 4% Phenobarbitone PhEur
Phenobarbitone may reduce the activity of some drugs by increasing the rate of metabolism through induction of drug-metabolisingenzymes in liver microsomes.
Uses:
Phenobarbitone is an antiepileptic agent for use in the control of
Overdosage may result in coma severe respiratory and cardiovascular depression hypotension and shock leading to renal failure anddeath. Following the recent ingestion of an overdose the stomach Dosage and administration:
may be emptied by lavage. The prime objectives of management arethen intensive symptomatic and supportive therapy with particular attention being paid to the maintenance of cardiovascular respiratory and renal functions and to the maintenance of the Withdrawal periods:
Operator warnings:
In case of accidental ingestion seek medical attention immediatelyadvising medical services of barbiturate poisoning or show this Steady state serum concentrations are not reached until 1 - 2 weeksafter treatment is initiated. The full effect of the medication does Flammable keep away from sources of ignition. Do not smoke.
not appear for two weeks and doses should not be increased duringthis time.
If seizures are not being controlled the dosage may be increased by Pharmaceutical precautions:
20% at a time with associated monitoring of serum phenobarbitone levels. The phenobarbitone serum concentration may be checked after steady state has been achieved and if it is less than 15 microgram/ml the dose may be adjusted accordingly. If seizures recur the dose may be raised up to a maximum serum concentration of 45 Dispose of in accordance with local authority regulations.
microgram/ml. High plasma concentrations may be associated withhepatotoxicity. Blood samples should be taken at the same time to Legal category:
allow plasma phenobarbitone concentration to be determined preferably during trough levels shortly before the next dose ofphenobarbitone is due.
Package quantities:
30ml amber type III glass bottle with integral LDPE dropper and
Contra-indications warnings etc:
Child Resistant Closure: 100ml high density polyethylene bottle with Not for use in pregnant animals or nursing bitches.
integral syringe adapter insert and child resistant closure.
Do not administer to animals with impaired hepatic function.
Further information:
The antiepileptic effects of phenobarbitone are probably the result
Occasionally polyphagia polyuria and polydipsia have been reported of at least two mechanisms: - Decreased monosynaptic transmission but these effects are usually transitory and disappear with continued which presumably results in reduced neuronal excitability and an increase in the motor cortex's threshold for electrical stimulation.
Toxicity may develop at doses over 20mg/kg/day or when serum After oral administration of phenobarbitone to dogs the drug is phenobarbitone levels rise above 45 microgram/ml.
rapidly absorbed and maximal plasma concentrations are reachedwithin 4 - 8 hours. Bioavailability is between 86% - 96%. About 45% In the light of isolated reports describing hepatotoxicity associated of the plasma concentration is protein bound. Metabolism is by with combination anticonvulsant therapy it is recommended that:- aromatic hydroxylation of the phenyl group in the para position andabout one third of the drug is excreted unchanged in the urine.
1. Hepatic function is evaluated prior to initiation of therapy (e.g.
Elimination half-lives vary considerably between individuals and 2. Therapeutic phenobarbitone serum concentrations are monitored Marketing authorisation number:
to enable the lowest effective dose to be used. Typically concentrations of 15 - 45microgram/ml are effective in controllingepilepsy.
3. Hepatic function is re-evaluated on a regular (6 to 12 month) basis.
4. Seizure activity is re-evaluated on a regular basis.
Withdrawal of phenobarbitone or transition to or from another typeof antiepileptic therapy should be made gradually to avoidprecipitating an increase in the frequency of seizures.
Disclaimer: Every effort has been made to ensure the accuracy of the information provided. However, it remains the responsibility of the readers to familiarise themselves with the product information contained on the product label or package insert. Data Valid as of : December 2003

Source: http://www.canineepilepsy.co.uk/Documents/data_Pheno_sol.pdf