Doxy-50

New Zealand - English - Medsafe (Medicines Safety Authority)

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Active ingredient:
Doxycycline hydrochloride 57 mg (As docyclycine hyclate = Doxycycline 50mg);  
Available from:
Douglas Pharmaceuticals Limited
INN (International Name):
Doxycycline hydrochloride 57 mg (As docyclycine hyclate = Doxycycline 50mg)
Dosage:
50 mg
Pharmaceutical form:
Tablet
Composition:
Active: Doxycycline hydrochloride 57 mg (As docyclycine hyclate = Doxycycline 50mg)   Excipient: Colloidal silicon dioxide Magnesium stearate Maize starch Microcrystalline cellulose Opadry white Y-1R-7000B
Units in package:
Blister pack, physican's sample, 7 tablets
Class:
Prescription
Prescription type:
Prescription
Manufactured by:
Hovione PharmaScience Limited
Product summary:
Package - Contents - Shelf Life: Blister pack, physican's sample - 7 tablets - 36 months from date of manufacture stored at or below 30°C protect from light - Blister pack, - 30 tablets - 36 months from date of manufacture stored at or below 30°C protect from light - Bottle, plastic, - 30 tablets - 24 months from date of manufacture stored at or below 30°C protect from light
Authorization number:
TT50-2886/3
Authorization date:
1996-05-17

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INFORMATIONFOR

CONSUMERS

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Information

DOXY-50TABLETS

DOXY-100TABLETS

Doxycycline50mgand100mgtablets

Whatisinthisleaflet

ThisleafletanswerssomecommonquestionsaboutDOXYtablets.Itdoesnotcontainalltheavailable

information.

Itdoesnottaketheplaceoftalkingtoyourdoctorandpharmacist.

Allmedicineshaverisksandbenefits.YourdoctorweighedtherisksofyoutakingDOXYtablets

againstthebenefitsthismedicineisexpectedtohaveforyou.

Ifyouhaveanyconcernsabouttakingthismedicine,askyourdoctororpharmacist.

Keepthisleafletwiththemedicine.Youmayneedtoreaditagain.

WhatDOXYtabletsareusedfor

Doxycyclineisabroadspectrumantibiotic.Thismeansitcanbeusedtotreatawiderangeof

organisms.

Doxycyclinebelongstoaclassofmedicinescalled tetracyclines.Thesemedicinesworkbykillingor

stoppingthegrowthofbacteriawhichcauseinfection.Theyalsoworkagainstparasites.

Itisusedtotreatinfectionsofthe:

chest

urethra

womb

rectum

DOXYtabletsmaybeusedtoaidmedicinessuchasamoebicides(usedtotreatparasites).

DOXYtabletsmaybeusedtoaidmedicinessuchasamoebicides(usedtotreatparasites).

DOXYtabletsmayalsobeusedtotreatsevereacne.

DOXYtabletsareonlyusedtotreatinfectionsthatwillrespondtoit.Someinfectionsareresistanttothe

effectsofdoxycycline.

YourdoctormayhaveprescribedDOXYtabletsforanotherreason.

AskyourdoctorifyouhaveanyquestionsaboutwhyDOXYtabletshavebeenprescribedforyou.

Thismedicineisavailableonlywithadoctor'sprescription.

BeforeyoutakeDOXYtablets

Whenyoumustnottakeit

DonottakeDOXYtabletsifyouhavehadanallergyto:

doxycycline

othertetracyclineantibiotics

anyoftheingredientslistedattheendofthisleaflet

SymptomsofanallergicreactiontoDOXYtabletsmayinclude:

skinrash

difficultybreathing

hayfever

swelling

DonottakeDOXYtabletsifyouareunder12yearsofage.

DOXYtabletsmaycausepermanenttoothdiscolourationifusedduringtoothdevelopment

DonottakeDOXYtabletsifyouarepregnantorbreastfeeding

Studiesindicatetetracyclinescrosstheplacentaanddoxycyclinehasbeenfoundinbreastmilk.

Doxycyclineproducestoxiceffectsonthedevelopingfoetusanddelaysbonedevelopment.Itmayalso

decreasethegrowthrateofthelegbonesinprematurebabies.

DOXYtabletsmaycausepermanenttoothdiscolourationifusedduringtoothdevelopment(lasthalfof

pregnancy,infancyandinchildhoodtotheageof12years).Itmayalsocausetheenamelsurrounding

thetoothtobecomedefective.

DonottakeDOXYtabletsifthepackagingistornorshowssignsoftamperingorifthetablets

showvisiblesignsofdeterioration.

DonottakeDOXYtabletsaftertheexpirydate(EXP)printedonthepack.

Ifyoutakethismedicineaftertheexpirydatehaspassed,itmaynotworkaswell.

Beforeyoustarttakingit

Tellyourdoctororpharmacistifyouareallergictoanyothermedicines,foods,dyesorpreservatives.

Tellyourdoctororpharmacistifyouareallergictoanyothermedicines,foods,dyesorpreservatives.

Tellyourdoctorifyouintendtobecomepregnantorbreastfeed.

Yourdoctorwilldiscusstherisksandbenefitsoftakingthismedicineduringpregnancy.

Tellyourdoctorifyouaretakingdrugstothintheblood

DOXYtabletsmaycausephotosensitivity,whichresultsinsunburn.Treatmentshouldbestoppedatthe

firstsignofredness. WearprotectiveclothingandsunscreenwhiletakingDOXYtablets.

UseofDOXYtabletsmayoccasionallyresultinovergrowthoforganisms,whichareresistanttoit.

Treatmentshouldbestoppedandanalternativeantibioticused.

DOXYtabletsareunlikelytoproduceaneffectontheabilitytodriveorusemachinery,however,care

shouldbetakenuntilyouknowhowthismedicineaffectsyou.

DOXYtabletsmayincreasetheeffectsofsystemiclupuserythematous(lupus).Adiseasewherethe

bodyattacksit'sowncellsandtissues.

Thereisnoevidencethismedicineisaddictive.

Takingothermedicines

Tellyourdoctorifyouaretakinganyothermedicines,includingmedicinesthatyoubuywithouta

prescriptionfromyourpharmacy,supermarketorhealthfoodshop.Somemedicinesmayinterferewith

DOXYtablets.Theseinclude:

antibioticscalledpenicillins

phenytoinandbarbiturates-usedtotreatepilepsy

ironpreparations-includingvitaminpreparationswhichcontainiron

Yourdoctorandpharmacistmayhavemoreinformationonmedicinestobecarefulwithoravoidwhile

takingthismedicine

HowDOXYtabletsaretaken

Carefullyfollowalldirectionsgiventoyoubyyourdoctor.Theirdirectionsmaydifferfromthe

informationcontainedinthisleaflet.Ifyoudonotunderstandtheinstructionsonthelabel,askyour

doctororpharmacistforhelp.

Yourdoctorwilldecidewhatdoseof,andforhowlongyoushouldtakeDOXYtablets.Thisdepends

onyourmedicalconditionandotherfactors,suchasyourweight.DOXYtabletsareusuallytakenupto

12weeksforacnetreatmentandonetotwoweeksfortreatinginfections.

DOXYtabletsshouldbetakenwithadequateamountsoffoodorwaterandyoushouldremain

uprightforupto2hoursafterwards.Thisistoavoidirritationandulcerationtoyour

oesophagus(food-pipe).

Whentotakeit

TakeDOXYtabletsduringorimmediatelyafteramealataboutthesametimeeachday(usuallyinthe

TakeDOXYtabletsduringorimmediatelyafteramealataboutthesametimeeachday(usuallyinthe

morning).Iftakenonanemptystomach,DOXYtabletsmaycauseastomachupset.Iftreatmentisfor

acne,alwaystakeDOXYtabletswithfood.

LateeveningingestionofDOXYtabletsshouldbeavoided.

Ifyouforgettotakeit

Ifitisalmosttimeforyournextdose,skipthedoseyoumissedandtakeyournextdosewhenyouare

meantto.Otherwise,takeitassoonasyourememberandthengobacktotakingitasyouwould

normally.

Donottakeadoubledosetomakeupforthedosethatyoumissed.

Ifyouarenotsurewhattodo,askyourdoctororpharmacist.

WhileyouareusingDOXYtablets

Thingsyoumustdo

Ifthesymptomsofyourinfectiondonotimprovewithindays,ortheybecomeworse,tellyourdoctor.

IfyoubecomepregnantwhileyouaretakingDOXYtablets,tellyourdoctor.

Ifyouareabouttostarttakinganewmedicinetellyourdoctorandpharmacistthatyouaretaking

DOXYtablets.

Thingsyoumustnotdo

DonotstoptakingDOXYtabletsorlowerthedosagewithoutcheckingwithyourdoctor.Youshould

takethefullcourseofDOXYtabletsevenifyoufeelwellortheinfectionmayreappear.

DonotgiveDOXYtabletstoanyoneelse,eveniftheyhavethesameconditionasyou.

DonottakeDOXYtabletstotreatanyothercomplaintsunlessyourdoctortellsyouto.

SideEffects

Allmedicinescanhavesideeffects.Sometimestheyareserious,mostofthetimetheyarenot.

Tellyourdoctorifyounoticeanyofthefollowingandtheyworryyou:

lossofappetite

nausea

diarrhoea

difficultyswallowing

headache

Tellyourdoctorimmediately,orgotothenearestAccidentandEmergencyDepartmentatyour

hospitalifyounoticeanyofthefollowing:

hospitalifyounoticeanyofthefollowing:

inflammation(heat,pain,swellingorredness)of:thetongue,theintestinalarea,theregionaround

thegenitalsandanus(withthrush)

skinreactions-discolouredspotsorpatchesofskin,flushed,flaky,itchyand/orredskin

searingpainintheoesophagus(food-pipe)

swelling

purplishorbrownish-reddiscolourationundertheskin

sharpchestpain

difficultybreathing

fatigue

DOXYtabletsmayincreasetheeffectsofsystemiclupuserythematous(lupus).Adiseasewherethe

bodyattacksit'sowncellsandtissues.

StoptakingDOXYtabletsimmediatelyandtellyourdoctorifyoubecomesensitivetosunlight.

Symptomsare:severesunburn,redness,itchingandrash.

Ifyouexperienceseverestomachcramps,diarrhoeaorbothincombinationwithfeverseveralweeks

afterfinishingDOXYtablets,tellyourdoctorimmediately.Youmayhaveaseriousconditionaffecting

yourbowel.Donottakeanydiarrhoeamedicinewithoutcheckingwithyourdoctorfirst.

Othersideeffectsnotlistedabovemayoccurinsomepatients.

Tellyourdoctororpharmacistifyounoticeanythingelsethatismakingyouunwell

Overdose

Immediatelytelephoneadoctor,orthePoisonsInformationCentre(telephone0800POISONand0800

764766)orgototheaccidentandEmergencyDepartmentatyournearesthospital,ifyouthinkyouor

anyoneelsemayhavetakentoomanyDOXYtablets.Dothiseveniftherearenosignsofdiscomfortor

poisoning.

Storage

StoreDOXYtabletsbelow30°C.

DonotstoreDOXYtabletsinthebathroomornearasink.Donotleaveitinthecaronhotdays.Heat

anddampnesscandestroysomemedicines.

Keepyourtabletsintheoriginalpacktheyareprovidedinuntilitistimetotakethem.Ifyoutakethe

tabletsoutofthepacktheymaynotkeepwell.

Keepitoutofreachofchildren.Alockedcupboardatleastone-and-a-halfmetresabovethegroundisa

goodplacetostoremedicines.

Disposal

Ifyourdoctortellsyoutostoptakingthismedicineorthetabletshavepassedtheirexpirydate,askyour

pharmacistwhattodowithanythatareleftover

Productdescription

Whatitlookslike

DOXY-50tabletsare:white,filmcoated,circularbiconvextablets,havingadiameterofapproximately

6.3mm.Theycomeinbottlescontaining30tabletsandcalendarpackscontaining30tablets.

DOXY-100tabletsare:white,film-coated,circular,biconvextabletsscoredononesideandhavinga

diameterof8mm.Theycomeinbottlescontaining100tablets

Sponsor

DouglasPharmaceuticalsLtd

CentralParkDrive,Lincoln

AUCKLAND1008

DateofPreparation:09 th May2007

1 | P a g e

New Zealand Data Sheet

1.

PRODUCT NAME

Doxy-50 tablets

Doxy-100 tablets

2.

QUALITATIVE AND QUANTITATIVE COMPOSITION

Each Doxy-50 tablet contains doxycycline hydrochloride 57 mg (as hyclate, equivalent to

doxycycline 50 mg)

Each Doxy-100 tablet contains doxycycline hydrochloride 114 mg (as hyclate, equivalent to

doxycycline 100 mg)

Excipient(s) with known effect

For the full list of excipients, see section 6.1.

3.

PHARMACEUTICAL FORM

Doxy-50 and Doxy-100 tablets are white, film coated, circular biconvex tablet.

Doxy-50 tablets have a diameter of approximately 6.3 mm.

Doxy-100 tablets are scored on one side and have a diameter of 8 mm.

4.

CLINICAL PARTICULARS

4.1.

Therapeutic indications

Doxycycline is indicated in the treatment of uncomplicated chest, urethral, endocervical or rectal

infections in adults caused by susceptible organisms (see below) as shown by culture and

sensitivity testing. It may also be a useful adjunct to amoebicides in acute intestinal amoebiasis

and has a place as adjunctive therapy in severe acne. Doxycycline is active against the following

organisms:

Rickettsiae: rocky mountain spotted

Fever, typhus fever and the typhus group, Q fever, rickettsial pox, and tick fevers

Mycoplasma pneumoniae

Agents of lymphogranuloma venereum and granuloma inguinale

The spirochetal agent of relapsing fever (Borrelia recurrentis)

Chlamydia trachomatis

Haemophilis ducreyi (chancroid)

2 | P a g e

Pasteurella pestis, and Pasteurella tularensis, Bartonella bacilliformis, Bacteroids species,

Vibriocomma and Vibrio fetus and Brucella species (in conjunction with an

aminoglycoside)

Doxycycline may be active against the following organisms although this should be confirmed by

culture and sensitivity testing since many strains are resistant.

Neisseria gonorrhoeae

Escherichia coli

Enterobacter aerogenes

Shigella species

Mima species and Herellea species

Haemophilis influenzae

Klebsiella species

Streptococcus species

Streptococcus pneumoniae

Staphylococcus aureus in respiratory, skin or soft tissue infection.

When penicillin is contraindicated, doxycycline is an alternative medicine in the treatment of

infections due to:

Treponema pallidum and Treponema pertenue (syphilus and yaws)

Listeria monocytogenes

Clostridium species

Bacillus anthracis

Fusobacterium fusiforme (Vincent's infection)

Actinomyces species.

4.2.

Dose and method of administration

Dose

Adults

The usual dose in adults is 200 mg on the first day of treatment followed by a maintenance dose

of 100 mg/day. This may be given as either a single dose or divided doses administered every 12

hours.

In the management of more severe infections 200 mg daily should be given throughout the

treatment period. Therapy should be continued at least 24-48 hours after symptoms and fever

have subsided. If used in streptococcal infections, therapy should be continued for 10 days to

prevent the development of rheumatic fever or glomerulonephritis.

For the treatment of acne vulgaris the recommended dose is 50 mg of doxycycline taken daily

with food, for up to 12 weeks.

3 | P a g e

In the treatment of acute gonococcal anterior urethritis in males, administer either: 200 mg stat

and 100 mg at bedtime on the first day followed by 100 mg twice daily for 3-7 days, or 300 mg

stat followed by 300 mg one hour later. For acute gonococcal infections in females use 200 mg

twice daily.

When treating uncomplicated urethral, endocervical or rectal infection in adults caused by

chlamydia trachomatis, give 100 mg twice daily for at least 7 days. The treatment of primary or

secondary syphilis requires 300 mg daily in divided doses for at least 10 days.

Children

For children over 12 years of age, the recommended dosage schedule for those under 50 kg is 4

mg/kg on the first day and 2 mg/kg daily subsequently. For children over 50 kg the usual adult

dose is used.

Method of Administration

In all cases Doxy should be administered with adequate amounts of fluid or food and the patient

should remain sitting or standing for up to 2 hours afterwards to prevent the possible

development of oesophageal irritation.

4.3.

Contraindications

Hypersensitivity to doxycycline, or any other ingredient in Doxy tablets.

Children under 12 years of age. The use of drugs of the tetracycline class, including

doxycycline, during tooth development may cause permanent discolouration of the

teeth (yellow-grey-brown). This adverse reaction is more common during long term use

of the medication but has been observed following repeated short-term courses. Enamel

hypoplasia has also been reported.

Pregnancy. Tetracyclines given during pregnancy affect teeth and skeletal development

(refer to section 4.6 and 5.3).

Nursing mothers. Tetracyclines are excreted into milk and affect teeth and skeletal

development (refer to section 4.6 and 5.3).

4.4.

Special warnings and precautions for use

Clostridium difficile associated diarrhoea (CDAD) and antibiotic associated

pseudomembranous colitis

Clostridium difficile associated diarrhoea (CDAD) and antibiotic associated pseudomembranous

colitis have been reported with nearly all antibacterial agents including doxycycline and may

range in severity from mild diarrhoea to fatal colitis. Treatment with antibacterial agents alters

the normal flora of the colon leading to overgrowth of C. difficile and C. difficile produces toxins

A and B which contribute to the development of CDAD. Hypertoxin producing strains of C.

difficile cause increased morbidity and mortality, as these infections can be refractory to

antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who

present with diarrhoea following antibiotic use. Careful medical history is necessary since CDAD

4 | P a g e

has been reported to occur over two months after the administration of antibacterial agents.

Mild cases usually respond to drug discontinuation alone. However, in moderate to severe cases

appropriate therapy with a suitable oral antibacterial agent effective against Clostridium difficile

should be considered. Fluids, electrolytes and protein replacement should be provided when

indicated. Drugs which delay peristalsis, e.g. opiates and diphenoxylate with atropine may

prolong and/or worsen the condition and should not be used.

Gastrointestinal irritation

Rarely, oesophagitis and oesophageal ulceration have been reported in patients receiving

doxycycline tablets. Most of these patients took medication immediately before going to bed.

Administration of adequate amounts of fluid with the tablets is recommended to reduce the risk

of oesophageal irritation and ulceration, and late evening ingestion of the dose should be

avoided.

To reduce the possibility of gastric irritation, it is recommended that doxycycline be given with

food or milk. The absorption of doxycycline is not markedly influenced by simultaneous ingestion

of food or milk.

Other considerations

In venereal disease when coexistent syphilis is suspected, proper diagnostic measures including

a dark field examination should be done before treatment is started and the blood serology

repeated monthly for at least four months.

In long term therapy, periodic laboratory evaluation of organ systems, including haematopoietic,

renal and hepatic studies should be performed.

If doxycycline is used to treat infections due to group A beta-haemolytic streptococci, treatment

should continue for at least 10 days.

Abnormal hepatic function has been reported rarely and has been caused by both oral and

parenteral administration of tetracyclines, including doxycycline.

As with other tetracyclines, doxycycline forms a stable calcium complex in any bone forming

tissue. A decrease in fibula growth rate has been observed in pre-matures given oral

tetracycline. This reaction was shown to be reversible when the medicine was discontinued.

Photosensitivity manifested by an exaggerated sunburn reaction has been observed in some

individuals taking tetracyclines. Treatment should be discontinued at the first evidence of skin

erythema.

The use of Doxy may occasionally result in overgrowth of non-susceptible organisms. If a

resistant organism appears, the antibiotic should be discontinued, and appropriate therapy

instituted. In long term therapy, because tetracyclines have been shown to depress plasma

5 | P a g e

prothrombin activity, patients who are on anti-coagulant therapy may require downward

adjustment of their anti-coagulant dosage.

Paediatric population

Increased Intracranial Pressure

The use of tetracyclines in infants, even in the usual therapeutic doses, may cause increased

intracranial pressure and bulging of the fontanelles. Discontinuation of therapy results in prompt

return of the pressure to normal.

4.5.

Interaction with other medicines and other forms of interaction

Doxy may interfere with the bacterial effect of penicillins and vice versa.

Anticoagulants

There have been reports of prolonged prothrombin time in patients taking warfarin and

doxycycline. Because the tetracyclines have been shown to depress plasma prothrombin activity,

patients who are on anticoagulant therapy may require downward adjustment of their

anticoagulant dosage.

Methoxyflurane

The concurrent use of tetracyclines and methoxyflurane has been reported to result in fatal

renal toxicity.

Oral contraceptives

There have been anecdotal reports that concurrent use of tetracyclines may render oral

contraceptives less effective.

Antacids and Iron preparations

Antacids containing aluminium, calcium or magnesium, or other medications containing these

cations; bismuth salts; and preparations containing iron impair absorption and should not be

given to patients taking doxycycline.

Medicines reducing doxycycline concentrations

Plasma levels of doxycycline are reduced by the ingestion of alcohol or the administration of

barbiturates, anticonvulsants (phenytoin, carbamazepine), disodium hydrogen edetate, sodium

bicarbonate, sodium lactate, acetazolamide and ethoxzolamide.

4.6.

Fertility, pregnancy and lactation

Pregnancy

The importance of this in humans is not known, however, Doxy should not be used in pregnant

women unless the benefit outweighs the risk (refer to section 5.3).

6 | P a g e

Breast-feeding

Doxy has been found in the milk of lactating women it should not be used in nursing mothers.

Fertility

Refer to section 5.3.

4.7.

Effects on ability to drive and use machines

The effect of doxycycline on the ability to drive or operate heavy machinery has not been

studied. There is no evidence to suggest that doxycycline may affect these abilities.

4.8.

Undesirable effects

More Common Reactions

Skin and subcutaneous tissue: Photosensitive skin reactions (see section 4.4), erythematous

rash, maculopapular rash, morbilliform rash, pustular rash, urticaria, photo-onycholysis and

discolouration of the nails.

Gastrointestinal: Nausea, anorexia, vomiting, dysphagia, diarrhoea, oesophagitis, oesophageal

ulceration, abdominal pain, glossitis, black hairy tongue.

Hypersensitivity reactions: Urticaria, exacerbation of systemic lupus erythematosus.

Hepatic: Cholestatic hepatitis, fatty liver degeneration.

Renal: Dose related increase in serum urea.

Musculoskeletal: Tooth discolouration, enamel hypoplasia.

Others: Bulging fontanelles have been reported in young infants following full therapeutic

dosage. The sign disappeared rapidly when the drug was discontinued.

When given over prolonged periods, tetracyclines have been reported to produce brown-black

microscopic discolouration of thyroid glands. No abnormalities of thyroid function studies are

known to occur.

Less Common Reactions

Gastrointestinal: Enterocolitis (see section 4.4), inflammatory lesions (with monilial overgrowth)

in the anogenital region; dyspepsia and pseudomembranous colitis (see section 4.4); C. difficile

diarrhoea.

Hepatic: Abnormal hepatic function has been reported rarely (< 1 in 1000), hepatotoxicity.

7 | P a g e

Skin and subcutaneous tissue: Exfoliative dermatitis; Stevens-Johnson syndrome, Toxic

Epidermal Necrolysis (TEN).

Musculoskeletal: Arthralgia; myalgia.

Renal: Acute renal failure.

Hypersensitivity reactions: Angioneurotic oedema, anaphylaxis, anaphylactic shock,

anaphylactic reaction, anaphylactoid purpura, serum sickness, pericarditis, hypotension,

dyspnoea, peripheral oedema, tachycardia, erythema multiforme.

Blood and lymphatic system: Leucopenia, thrombocytopenia purpura, increase in prothrombin

time, haemolytic anaemia, eosinophilia.

Nervous system: Flushing, malaise, headache, confusion, taste loss, stupor, hypoaesthesia,

paraesthesia, somnolence, benign intracranial hypertension in adults, increased intracranial

pressure in infants.

Eye: Conjunctivitis, periorbital oedema.

Ear: Tinnitus.

Psychiatric: Depression, anxiety, hallucination.

Respiratory: Bronchospasm.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicine is important. It allows

continued monitoring of the benefit/risk balance of the medicine. Healthcare professionals are

asked to report any suspected reactions https://nzphvc.otago.ac.nz/reporting/

4.9.

Overdose

Symptoms

No reports of overdosage have been received.

Management

If such a case occurs, treatment requires discontinuation of Doxy and use of symptomatic

treatment measures.

For advice on the management of overdose please contact the National Poisons Centre on 0800

POISON (0800 764766).

8 | P a g e

5.

PHARMACOLOGICAL PROPERTIES

5.1.

Pharmacodynamic properties

Pharmacotherapeutic group: Tetracyclines, ATC code: J01AA02

Mechanism of action

Doxycycline is a broad-spectrum antibiotic that is primarily bacteriostatic. It is thought to exert

its antimicrobial effect by inhibition of protein synthesis. It prevents the binding of amino-acyl-

tRNA to the messenger RNA-30S ribosomal subunit. The binding of fMet-tRNA is especially

sensitive. As a result, initiation, and therefore polyribosome formation, are blocked. Doxycycline

inhibits only rapidly multiplying organisms.

5.2.

Pharmacokinetic properties

Absorption

Doxycycline is virtually completely absorbed after oral administration of either tablets and the

absorption is not notably influenced by the ingestion of food or milk.

Distribution

Peak serum levels of approximately 2.6 mcg/ml are achieved at 2 hours following a 200 mg

tablet dose. Doxycycline diffuses readily into most body tissues, fluid and/or cavities and the

volume of distribution has been measured as 0.7 L/kg. Plasma protein binding is variable.

Bioformation and Elimination

Doxycycline is concentrated by the liver in the bile. It is also excreted in the urine as the

unchanged medicine in high concentration. The serum half-life of doxycycline ranges from 18-22

hours and this is not altered by severe renal failure, haemodialysis, age or hepatic failure.

5.3.

Preclinical safety data

Carcinogenicity

Animal studies conducted in rats and mice have not provided conclusive evidence that

tetracyclines may be carcinogenic or that they impair fertility. In two mammalian cell lines,

positive responses for mutagenicity occurred at concentrations of 60 and 10 mcg/ml

respectively. In humans no association between tetracyclines and these effects have been made.

Teratogenicity

Results of animal studies indicate that tetracyclines cross the placenta, are found in foetal

tissues and have toxic effects on the developing foetus manifested by retardation of skeletal

development.

9 | P a g e

6.

PHARMACEUTICAL PARTICULARS

6.1.

List of excipients

Doxy-50 and Doxy-100 tablet contains colloidal silicon dioxide, magnesium strearate, maize

starch, microcrystalline cellulose, Opadry white Y-1R-7000B.

6.2.

Incompatibilities

Not applicable.

6.3.

Shelf life

24 months in bottles and 36 months in blister.

6.4.

Special precautions for storage

Store at or below 30°C. Protect from light.

6.5.

Nature and contents of container

Doxy-50 tablets: 30 tablets in a bottle; 30 tablets or 7 tablets in blister pack

Doxy-100 tablets: 100 tablets in a bottle

Not all strengths or pack sizes may be marketed.

6.6.

Special precautions for disposal and other handling

Any unused medicine or waste material should be disposed of in accordance with local

requirements.

7.

MEDICINE SCHEDULE

Prescription medicine

8.

SPONSOR

Douglas Pharmaceuticals Ltd

P O Box 45 027

Auckland 0651

New Zealand

Phone: (09) 835 0660

9.

DATE OF FIRST APPROVAL

Doxy-50 tablets: 17 May 1996

10 | P a g e

Doxy-100 tablets: 08 Aug 1980

10.

DATE OF REVISION OF THE TEXT

22 January 2019

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