Phenoleptil

Main information

  • Trade name:
  • Phenoleptil 25mg tablets for dogs
  • Pharmaceutical form:
  • Tablet
  • Medicine domain:
  • Animals
  • Medicine type:
  • Allopathic drug

Documents

Localization

  • Available in:
  • Phenoleptil 25mg tablets for dogs
    Ireland
  • Language:
  • English

Therapeutic information

  • Therapeutic group:
  • Phenobarbital
  • Therapeutic area:
  • Dogs

Other information

Status

  • Source:
  • HMA - Europe
  • Authorization number:
  • UK/V/0336/003
  • Authorization date:
  • 24-10-2012
  • EU code:
  • UK/V/0336/003
  • Last update:
  • 09-08-2016

Summary of Product characteristics: dosage,interactions,side effects

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AN:01562/2011

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SUMMARYOFPRODUCTCHARACTERISTICS

1. NAMEOFTHEVETERINARYMEDICINALPRODUCT

PHENOLEPTIL25mgTabletsfordogs

2. QUALITATIVEANDQUANTITATIVECOMPOSITION

Eachtabletcontains

Activesubstance mg

Phenobarbital 25

Excipient(s):

Forafulllistofexcipients,seesection6.1.

3. PHARMACEUTICALFORM

Tablet.

Whitetooffwhite,circular,convextabletwithbrownspecklesandacrossedscoreline

ononeside(8mmdiameter).

Thetabletscanbedividedintotwoorfourequalparts.

4. CLINICALPARTICULARS

4.1Targetspecies

Dog.

4.2Indicationsforuse,specifyingthetargetspecies

Preventionofseizuresduetogeneralisedepilepsyindogs.

4.3Contraindications

Donotuseincaseofhypersensivitytotheactivesubstance.

Donotuseinanimalswithseriousimpairedhepaticfunction.

Donotuseinanimalswithseriousrenalorcardiovasculardisorders.

Donotuseindogsweighinglessthan2.5kgbodyweight.

4.4Specialwarningsforthetargetspecies

Thedecisiontostartantiepilepticdrugtherapywithphenobarbitalshouldbeevaluated

foreachindividualcaseanddependsonnumber,frequency,durationandseverityof

seizuresindogs.

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Generalrecommendationsforinitiatingtherapyincludeasingleseizureoccurringmore

thanonceevery4-6weeks,clusterseizureactivity(i.e.morethanoneseizurewithin24

h)orstatusepilepticusregardlessoffrequency.

Toachievesuccessfultherapy,administrationoftabletsmustbeatthesametimeeach

day.

Withdrawalortransitionfromothertypesofantiepileptictherapyshouldbemade

graduallytoavoidprecipitatinganincreaseinthefrequencyofseizures.

Someofthedogsarefreeofepilepticseizuresduringthetreatment,butsomeofthe

dogsshowonlyaseizurereduction,andsomeofthedogsareconsideredtobenon-

responders.

4.5Specialprecautionsforuse

i)Specialprecautionsforuseinanimals

Dosesforsmallerdogscannotbeadjustedinaccordancewiththerecommended20%

regime,andthereforespecialcareshouldbetakeninmonitoringtheseanimals.Also

seesection4.9.

Cautionisrecommendedinanimalswithimpairedhepaticandrenalfunction,

hypovolemia,anemiaandcardiacorrespiratorydysfunction.

Theriskofhepatotoxicsideeffectscanbediminishedordelayedusinganeffective

dosethatisaslowaspossible.Monitoringofhepaticparametersisrecommendedin

caseofaprolongedtherapy

Itisrecommendedtoassesstheclinicalpathologyofthepatient2-3weeksafterstartof

treatmentandafterwardsevery4-6months,e.g.measurementofhepaticenzymesand

serumbileacids.Itisimportanttoknowthattheeffectsofhypoxiaetc.docause

increasedlevelsofhepaticenzymesafteraseizure.

Phenobarbitalmayincreasetheactivityofserumalkalinephosphataseand

transaminases.Thesemaydemonstratenon-pathologicalchanges,butcouldalso

representhepatotoxicity.Therefore,inthecaseofsuspectedhepatotoxicity,liver

functiontestsarerecommended.Increasedliverenzymevaluesdonotrequireadose

reductionofPhenobarbitaliftheserumbileacidsareinthenormalrange.

Instabilisedepilepticpatients,itisnotrecommendedtoswitchfromotherphenobarbital

formulationstoPhenoleptilTablets.However,ifthiscannotbeavoidedthenadditional

cautionshouldbetaken.Thisincludesmorefrequentplasmaconcentrationsamplingto

ensurethattherapeuticlevelsaremaintained.Monitoringforincreasedsideeffectsand

forhepaticdysfunctionshouldbeconductedmoreregularlyuntilstabilisationis

confirmed.

WithdrawaloftherapywithPhenobarbitalformulationsshouldbemadegraduallyto

avoidprecipitatinganincreaseinthefrequencyofseizures.

ii)Specialprecautionstobetakenbythepersonadministeringtheveterinary

medicinalproducttoanimals

Peoplewithknownhypersensitivitytobarbituratesshouldavoidcontactwiththe

veterinarymedicinalproduct.Washhandsafteruse.

Takeutmostcarethatchildrendonotcomeintocontactwiththeproduct.Childrenare

particularlyatriskofintoxicationwhichmayprovefatal.

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Incaseofaccidentalingestion,seekmedicaladviceimmediatelyandshowthe

packageleafletorthelabeltothephysician.Ifpossible,thephysicianshouldbe

informedaboutthetimeandamountofingestion,asthisinformationmayhelptoensure

thatappropriatetreatmentisgiven.

4.6Adversereactions(frequencyandseriousness)

Duringstartoftherapyataxia,sleepiness,slacknessanddizzinesscanoccurbutthese

effectsareusuallytransitoryanddisappearinmost,butnotall,patientswithcontinued

medication.

Someanimalscandemonstrateaparadoxicalhyperexcitability,particularlyafterfirst

startingtherapy.

Asthishyperexcitabilityisnotlinkedtooverdosage,noreductionofdosageisneeded.

Polyuria,polydipsiaandpolyphagiacanoccurataverageorhighertherapeuticactive

serumconcentrations;theseeffectscanbediminishedbylimitingintakeofbothfood

andwater.

Sedationandataxiaoftenbecomesignificantconcernsasserumlevelsreachthehigher

endsofthetherapeuticrange.

Highplasmaconcentrationsmaybeassociatedwithhepatotoxicity.

Phenobarbitalcanhavedeleteriouseffectsonstemcellsfrombonemarrow.

Consequencesareimmunotoxicpancytopeniaand/orneutropenia.Thesereactions

disappearaf terthetreatment’swithdrawal.

TreatingdogswithphenobarbitalmaylowertheirTT4orFT4serumlevels,howeverthis

maynotbeanindicationofhypothyroidism.Treatmentwiththyroidhormone

replacementshouldonlybestartedifthereareclinicalsignsofthedisease.

Ifadverseeffectsaresevere,adecreaseintheadministereddoseisrecommended.

4.7Useduringpregnancy,lactationorlay

Phenobarbitalcrossestheplacentalbarrierandathigherdoses(reversible)withdrawal

symptomsinnewbornscannotbeexcluded.Studiesinlaboratoryanimalshaveshown

evidenceofactionofphenobarbitalonprenatalgrowth,especiallyconcerningsexual

development.Neonatalbleedingtendencieshavebeenassociatedwithphenobarbital

treatmentduringpregnancy.AdministrationofVitaminKtothedamfor10daysbefore

parturitionmayhelptominimizetheseeffectsonthefetus.

Thesafetyoftheveterinarymedicinalproducthasnotbeenestablishedduring

pregnancyofdogs.Thebenefitsoftreatmentmaybegreaterthanthepotentialrisks

associatedwithepilepticseizuresonthefetus(hypoxiaandacidosis).Therefore,in

caseofpregnancy,terminationofantiepileptictreatmentisnotrecommended;however,

thedoseshouldbeaslowaspossible.

Phenobarbitalisexcretedinsmallamountsinbreastmilkandduringnursingpups

shouldbemonitoredcarefullyforundesiredsedativeeffects.Weaningearlymaybean

option.Ifsomnolence/sedativeeffects(thatcouldinterferewithsuckling)appearin

nursingnewborns,anartificialsucklingmethodshouldbechosen.

Useduringpregnancyandlactationonlyaccordinglytothebenefit/riskassessmentby

theresponsibleveterinarian.

4.8Interactionwithothermedicinalproductsandotherformsofinteraction

Atherapeuticdoseofphenobarbitalforantiepileptictherapycansignificantlyinduce

plasmaprotein(suchasα1acidglycoprotein,AGP),whichbinddrugs.Thereforespecial

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attentionmustbepaidtothepharmacokineticsanddosesofdrugssimultaneously

administered.

Theplasmaticconcentrationofcyclosporine,thyroidhormonesandtheophyllineis

decreasedinthecaseofconcurrentadministrationofphenobarbital.Theeffectiveness

ofthesesubstancesisdiminishedtoo.

Cimetidineandketoconazoleareinhibitorsofhepaticenzymes:concurrentusewith

phenobarbitalcaninduceanincreaseofserumconcentrationofphenobarbital.

Concurrentusewithpotassiumbromideincreasestheriskofpancreatitis.

Concurrentusewithotherdrugshavingacentraldepressiveactionlikenarcotic

analgesics,morphinicderivates,phenothiazines,antihistamines,clomipramineand

chloramphenicolcandecreasetheeffectofphenobarbital.

Phenobarbitalmayenhancethemetabolismof,andthereforedecreasetheeffectof,

antiepileptics,chloramphenicol,corticosteroids,doxycycline,betablockersand

metronidazole.

Thereliabilityoforalcontraceptivesislower.

Phenobarbitalmaydecreasetheabsorptionofgriseofulvin.

Thefollowingdrugscandecreasetheconvulsivethreshold:quinolones,high dosesofβ-

lactamantibiotic,theophyllin,aminophyllin,cyclosporineandpropofolforexample).

Medicationswhichmayaltertheseizurethresholdshouldonlybeusedifreally

necessaryandwhennosaferalternativeexists.

4.9Amountstobeadministeredandadministrationroute

Administrationroute

Fororaladministration.

Amountstobeadministered

Therecommendedinitialdosageis2.5mgphenobarbitalperkgbodyweighttwice

daily.Thecrossedscorelineononesideofthetabletallowsdivisionintotwo(eachpart

of12.5mgphenobarbital)orfour(eachpartof6.25mgphenobarbital)equalparts.

Tabletsmustbegivenatthesametimeeachdaytoachievesuccessfultherapy.

Eventualadjustmentsofthisdosageshouldbemadeonthebasisofclinicalefficacy,

bloodlevelsandtheoccurrenceofundesirablesideeffects.Alsoseeundersection

4.5i).

Theserumphenobarbitalconcentrationsshouldbemeasuredaftersteadystatehas

beenachieved.Theidealtherapeuticrangeforserumphenobarbitalconcentrationis

between15and40µg/ml.Ifserumphenobarbitalconcentrationislessthan15µg/mlor

theseizuresarenotcontrolledthedosemaybeincreasedby20%atatime,with

associatedmonitoringofserumphenobarbitallevelsuptoamaximumserum

concentration45µg/ml.Theultimatedosesmayvaryconsiderably(rangingfrom1mgto

15mgperkgbodyweighttwicedaily)becauseofthedifferencesinphenobarbital

excretionanddifferencesinsensitivityamongpatients.

Iftheseizuresarenotbeingsatisfactorilycontrolledandifthemaximumlevel

concentrationisabout40µg/ml,thenthediagnosisshouldbereconsideredand/ora

secondantiepilepticproduct(suchasbromides)shouldbeaddedtothetreatment

protocol.

Instabilisedepilepticpatients,itisnotrecommendedtoswitchfromotherphenobarbital

formulationstoPhenoleptilTablets.However,ifthiscannotbeavoidedthenadditional

cautionshouldbetaken.Itisrecommendedtotrytoachieveassimilardosagesas

possiblecomparedwiththepreviousformulationusedtakingintoconsiderationcurrent

plasmaconcentrationmeasurements.Stabilisationprotocolsasforinitiatingtreatments

shouldbefollowed.Alsoseesection4.5i).

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4.10Overdose(symptoms,emergencyprocedures,antidotes),ifnecessary

Symptomsofoverdoseare:

-depressionofthecentralnervoussystemdemonstratedbysignsrangingfromsleepto

coma,

-respiratoryproblems,

-cardiovascularproblems,hypotensionandshockleadingtorenalfailureanddeath.

Incaseofoverdoseremoveingestedproductfromthestomach,forexamplebylavage.

Activatedcharcoalmaybegiven.Offerrespiratorysupport.

Thereisnospecificantidote,butCNSstimulants(likeDoxapram)maystimulatethe

respiratorycentre.Giveoxygensupport.

4.11Withdrawalperiod(s)

Notapplicable.

5. PHARMACOLOGICALPROPERTIES

Pharmacotherapeuticgroup:antiepileptics/barbituratesandderivates

ATCvetcode:QN03AA02.

5.1Pharmacodynamicproperties

Theantiepilepticeffectsofphenobarbitalareprobablytheresultofatleasttwo

mechanisms,beingdecreasedmonosynaptictransmission,whichpresumablyresultsin

reducedneuronalexcitabilityandanincreaseinthemotorcortex'sthresholdfor

electricalstimulation.

5.2Pharmacokineticparticulars

Afteroraladministrationofphenobarbitaltodogs,thedrugisrapidlyabsorbedand

maximalplasmaconcentrationsarereachedwithin4-8hours.Bioavailabilityisbetween

86%-96%,apparentvolumeofdistributionis0,75l/kgandasteadystateserum

concentrationisreached2-3weeksafterstartoftherapy.

About45%oftheplasmaconcentrationisproteinbound.Metabolismisbyaromatic

hydroxylationofthephenylgroupintheparaposition(p-hydroxyphenobarbital),and

about25%ofthedrugisexcretedunchangedintheurine.Eliminationhalf-livesvary

considerablybetweenindividualsandrangefromabout40-90hours.

Environmentalproperties

None.

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6. PHARMACEUTICALPARTICULARS

6.1Listofexcipients

DryBeefFlavour201627

LactoseMonohydrate

MicrocrystallineCellulose

SodiumStarchGlycolate(TypeA)

Silica,ColloidalAnhydrous

MagnesiumStearate

6.2Incompatibilities

Notapplicable.

6.3Shelflife

Shelf-lifeoftheveterinarymedicinalproductaspackagedforsale:3years.

Returnanydividedtabletstotheopenedblisterpackandusewithin48hours.

6.4.Specialprecautionsforstorage

Donotstoreabove30 o

C.

Keepthecontainerintheouterpackageinordertoprotectfromlight.

Dividedtabletsshouldbestoredintheopenblisterpack.

6.5Natureandcompositionofimmediatepackaging

100tabletsinacardboardcartoncontaining10aluminium/pvcblisterstripseachstrip

with10tablets.

500tabletsinacardboardcartoncontaining50aluminium/pvcblisterstripseachstrip

with10tablets.

Notallpacksizesmaybemarketed.

6.6Specialprecautionsforthedisposalofunusedveterinarymedicinal

productorwastematerialsderivedfromtheuseofsuchproducts

Anyunusedveterinarymedicinalproductorwastematerialsderivedfromsuchveterinary

medicinalproductsshouldbedisposedofinaccordancewithlocalrequirements.

7. MARKETINGAUTHORISATIONHOLDER

LeVetB.V.

Wilgenweg7

3421TVOudewater

TheNetherlands

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8. MARKETINGAUTHORISATIONNUMBER

Vm19994/4030

9. DATEOFFIRSTAUTHORISATION

28January2013

10 DATEOFREVISIONOFTHETEXT

January2013

Approved: 28/01/2013