Consumer medicine information




Brand name


Active ingredient





Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Frakas.

What is in this leaflet

This leaflet answers some common questions about FRAKAS.

It does not contain all of the available information. It does not take the place of talking to your doctor or pharmacist.

All medicines have benefits and risks. Your doctor has weighed the risks of you taking FRAKAS against the benefits they expect it will have for you.

If you have any concerns about taking this medicine, talk to your doctor or pharmacist.

Keep this leaflet with your medicine. You may need to read it again.

What FRAKAS is used for

FRAKAS is used to:

  • treat infections
  • control acne
  • prevent a form of malaria.

FRAKAS is an antibiotic and belongs to a group of medicines called tetracyclines. These medicines work by killing or stopping the growth of bacteria which cause infections or make acne worse. They also work against parasites that cause malaria. Tetracyclines will not work against viral infections such as colds or flu.

Your doctor may have prescribed FRAKAS for another reason. Ask your doctor if you have any questions about why FRAKAS has been prescribed for you.

FRAKAS is available only with a doctor's prescription.

There is no evidence that FRAKAS is addictive.

Before you take FRAKAS

When you must not take it

Do not take FRAKAS if you are allergic to medicines containing doxycycline or any other tetracycline medicine or any of the ingredients listed at the end of this leaflet.

Do not take FRAKAS if you are taking preparations containing Vitamin A, isotretinoin or etretinate. Ask your doctor or pharmacist if you are not sure if you are taking one of these medicines.

Do not take this medicine if you are more than 18 weeks pregnant or are breastfeeding. As with many medicines, tetracyclines may harm your developing or breast-feeding baby. Tetracyclines may cause enamel loss and staining of your child’s teeth or increase the pressure on your child’s brain. High doses of tetracyclines may also cause liver problems in pregnant women.

Do not take FRAKAS if the expiry date (Exp.) printed on the pack has passed.

Do not take FRAKAS if the packaging is torn or shows signs of tampering.

Do not give FRAKAS to children under 8 years of age. Doxycycline like other tetracyclines, may cause enamel loss and staining in developing teeth. It may also cause increased pressure on the brain if used in infants.

Before you start to take it

Tell your doctor if you are allergic to any other medicines, foods, dyes or preservatives.

Tell your doctor if you are pregnant or plan to become pregnant.

Tell your doctor if you are breastfeeding or wish to breastfeed.

If you have not told your doctor about any of the above, tell him/her before you start taking FRAKAS.

Taking other medicines

Tell your doctor if you are taking any other medicines, including any that you buy without a prescription from a pharmacy, supermarket or health food shop.

Some medicines may be affected by FRAKAS, or may affect how well it works. These include:

  • preparations containing Vitamin A
  • some medicines used for skin problems such as isotretinoin or etretinate
  • warfarin, a medicine used to stop blood clotting
  • methoxyflurane, an inhaled anaesthetic
  • the contraceptive (birth control) pill. FRAKAS may decrease the effectiveness of some birth control pills. Your doctor may advise you to use an additional method of contraception while you are taking FRAKAS.
  • another group of antibiotics called penicillins
  • barbiturates such as phenobarbitone
  • anticonvulsant medicines that are used to treat seizures, such as phenytoin and carbamazepine
  • sodium bicarbonate
  • acetazolamide, a medicine used to treat glaucoma

Some medicines may interfere with the absorption of FRAKAS. These include:

  • iron preparations including vitamin preparations that contain iron
  • antacids used for indigestion.

Your doctor can tell you what to do if you are taking any of these medicines.

If you are not sure whether you are taking any of these medicines, check with your doctor or pharmacist.

Your doctor and pharmacist have more information on medicines to be careful with or avoid while taking FRAKAS.

How to take FRAKAS

How much to take

For treating infections, the usual dose of FRAKAS is two 100 mg tablets on the first day followed by one 100 mg tablet each day from then on.

For controlling acne, the usual dose of FRAKAS is one 50 mg tablet each day.

For the prevention of malaria, the usual dose FRAKAS is one 100 mg tablet each day, commencing two days before entering the malarious area, during the visit, and for two weeks after leaving the area. FRAKAS is normally used in combination with another antimalarial medicine.

Depending on your condition and how you react to the medicine, your doctor may ask you to take a different dose.

Follow all directions given to you by your doctor and pharmacist carefully.

How to take FRAKAS

Swallow the tablets whole with a full glass of water or milk while sitting or standing upright. Do not lie down for at least half an hour after swallowing your tablet. This is to help avoid irritation to your food pipe, also called the oesophagus.

Take FRAKAS during or immediately after a meal, at about the same time each day (usually in the morning). If taken on an empty stomach, it may cause stomach upset.

If you forget to take FRAKAS

If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to.

Otherwise, take the missed dose as soon as you remember, and then go back to taking your tablets as you would normally.

Do not take a double dose to make up for the dose you missed.

If you are not sure what to do, ask your doctor or pharmacist.

How long to take FRAKAS for

Do not stop taking FRAKAS because you are feeling better. If you do not complete the full course prescribed by your doctor, all of the bacteria causing the infection may not be killed. These bacteria may continue to grow and multiply so that your infection may not clear completely or may return.

For treating infections, FRAKAS is usually taken for one or two weeks.

For controlling acne, FRAKAS is usually taken for a period up to 12 weeks.

For preventing malaria, FRAKAS is normally recommended to be taken up to a maximum of 8 weeks.

However, your doctor may prescribe FRAKAS for longer periods.

If you take too much FRAKAS (overdose)

Immediately telephone your doctor, or the Poisons Information Centre (telephone 13 11 26), or go to Accident and Emergency at the nearest hospital, if you think you or anyone else may have taken too much FRAKAS. Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention.

While you are taking FRAKAS

Things you must do

Before starting any new medicine, tell your doctor or pharmacist that you are taking FRAKAS.

Tell all the doctors, dentists and pharmacists who are treating you that you are taking FRAKAS.

If you become pregnant while taking FRAKAS, tell your doctor.

If you are taking FRAKAS for an infection and your symptoms do not improve within a few days, or if they become worse, tell your doctor.

If you get severe diarrhoea, tell your doctor or pharmacist immediately. Do this even if it occurs several weeks after you have stopped taking FRAKAS. Diarrhoea may mean that you have a serious condition affecting your bowel. You may need urgent medical care.

Do not take any diarrhoea medicine without first checking with your doctor.

If you are about to have any blood tests, tell your doctor that you are taking this medicine.

If you are taking iron preparations, including vitamins that contain iron or antacids (containing aluminium, calcium or magnesium), you must take them at least two hours before or two hours after this medicine, to make sure there is no problem with absorption.

Things you must not do

Do not stop taking FRAKAS because you are feeling better, unless advised by your doctor. If you do not complete the full course prescribed by your doctor, all the bacteria causing your infection may not be killed. These bacteria may continue to grow and multiply so that your infection may not clear completely or may return.

Do not use FRAKAS to treat any other conditions unless your doctor tells you to.

Do not give FRAKAS to anyone else, even if they have the same condition as you.

Things to be careful of

Protect your skin when you are in the sun, especially between 10 am and 3 pm. FRAKAS may cause your skin to be more sensitive to sunlight than it is normally. Exposure to sunlight may cause a skin rash, itching, redness, or severe sunburn.

If outdoors, wear protective clothing and use a 30+ sunscreen. If your skin does appear to be burning, stop taking FRAKAS and tell your doctor as soon as possible.

If you get thrush (a fungal infection which can affect the mouth and/or vagina) or any other infection while taking, or soon after stopping FRAKAS, tell your doctor. Sometimes the use of this medicine allows fungi to gorw as they are not killed by FRAKAS.

Side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking FRAKAS.

Like all other medicines, FRAKAS may have unwanted side effects in some people. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of the side effects.

Do not be alarmed by this list of possible side effects. You may not experience any of them.

Ask your doctor or pharmacist to answer any questions you may have.

Tell your doctor if you notice any of the following and they worry you:

  • oral thrush - white, furry, sore tongue and mouth
  • vaginal thrush - sore itchy vagina and/or discharge
  • rash or itching
  • nail changes
  • stomach upset or vomiting
  • difficulty in swallowing
  • sore mouth or tongue
  • mild irritation of the food pipe
  • taste loss
  • ringing or other persistent noise in the ears

These side effects are usually mild.

Tell your doctor as soon as possible if you notice any of the following:

  • depression
  • feeling anxious or nervous
  • muscle tenderness or weakness, not caused by exercise
  • painful swollen joints

Tell your doctor immediately or go to Accident and Emergency at the nearest hospital if you notice any of the following:

  • increased pressure in the brain (headache, blurred vision, vomiting)
  • severe blisters and bleeding in the lips, eyes, mouth, nose and genitals
  • severe skin reactions starting as painful red areas then larger blisters and ends with peeling layers of skin
  • difficulty swallowing
  • pain when swallowing
  • flaking of the skin
  • dizziness
  • fast heart rate
  • frequent bruising
  • passing less urine
  • yellowing of the eyes or skin (jaundice)
  • severe upper stomach pain often with nausea and vomiting (pancreatitis)
  • symptoms of an allergic reaction such as shortness of breath, wheezing or troubled breathing; swelling of the face, lips, tongue or other parts of the body; rash, itching or hives on the skin
  • a rare, potentially life-threatening, drug-induced sensitivity reaction that includes skin rashes, blood changes, fever and dysfunction of internal organs (eg. Liver, kidney, lung)
  • a reaction that can happen after starting FRAKAS therapy for a particular bacterial infection (spirochete infections, eg. Lyme disease); symptoms include fever, chills, muscle pain or worsening of skin rash

These are serious side effects. You may need urgent medical attention or hospitalisation.

After finishing it

Tell your doctor immediately you notice any of the following side effects, particularly if they occur several weeks after stopping FRAKAS:

  • severe abdominal cramps or stomach cramps
  • watery and severe diarrhoea, which may be bloody
  • fever in combination with one or both of the above.

These are rare but serious side effects. You may have a serious condition affecting your bowel. FRAKAS can cause some bacteria that are normally harmless and present in the bowel to multiply and cause the above symptoms. Therefore you may need urgent medical attention.

Do not take any medicine for diarrhoea without first checking with your doctor.

Other side effects not listed above may also occur in some patients. Tell your doctor if you notice anything that is making you feel unwell.

After using FRAKAS


Keep FRAKAS where children cannot reach it. A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.

Keep your tablets in a cool dry place where the temperature stays below 25°C.

Do not store FRAKAS or any other medicine in the bathroom or near a sink.

Do not leave FRAKAS in the car or on window sills. Heat and dampness can destroy some medicines.


If your doctor tells you to stop taking FRAKAS, or your tablets have passed their expiry date, ask your pharmacist what to do with any that are left over.

Product description

What it looks like

FRAKAS is a dull yellow, round, biconvex tablet.

Each pack contains 25 tablets.


The active ingredient in FRAKAS is doxycycline. Each FRAKAS tablet contains 50 mg of doxycycline.

The tablets also contain:

  • microcrystalline cellulose
  • sodium starch glycollate type A
  • hydrogenated castor oil
  • povidone
  • colloidal anhydrous silica
  • magnesium stearate.


Sandoz Pty Ltd
54 Waterloo Road
Macquarie Park, NSW 2113
Telephone: 1800 726 369

Frakas is distributed in Australia by:

Aspen Pharma Pty Ltd
34-36 Chandos Street
St. Leonards
NSW 2067

This leaflet was revised in August 2019

Australian Register Number: FRAKAS - AUST R 98653

Published by MIMS October 2019


Brand name


Active ingredient





1 Name of Medicine

Doxycycline monohydrate.

2 Qualitative and Quantitative Composition

Each Frakas tablet contains 50 mg doxycycline (as monohydrate).
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Frakas tablets - dull yellow, round, unscored, unmarked, biconvex tablets.

4 Clinical Particulars

4.1 Therapeutic Indications

Infections caused by the following microorganisms: Mycoplasma pneumoniae (primary atypical pneumonia); Rickettsiae (Queensland tick typhus, epidemic typhus fever, Q fever, murine endemic typhus fever, Australo-Pacific endemic scrub typhus); Chlamydia psittaci (psittacosis); Chlamydia trachomatis (lymphogranuloma venereum, trachoma, inclusion conjunctivitis).
(Doxycycline is indicated in the treatment of trachoma, although the infectious agent is not always eliminated, as judged by immunofluorescence. Inclusion conjunctivitis may be treated with oral doxycycline, or in combination with topical agents).
Borreliae (relapsing fever); Calymmatobacterium (Donovania) granulomatis (granuloma inguinale).
Infections caused by the following Gram negative microorganisms: Vibrio sp. (cholera); Brucella sp. (brucellosis; in conjunction with streptomycin); Yersinia pestis (plague); Francisella tularensis (tularaemia); Bartonella bacilliformis (bartonellosis); Bacteroides sp.
When penicillin is contraindicated, doxycycline is an alternative drug in the treatment of infections due to: Treponema pallidum (syphilis); Treponema pertenue (yaws); Neisseria gonorrhoea (see Section 4.2 Dose and Method of Administration).


Frakas is not the drug of choice in the treatment of any type of staphylococcal infection or infections caused by Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus pyogenes, Streptococcus faecalis or any type of enteric bacteria because many strains of these organisms have been shown to be resistant to doxycycline. Frakas should not be used in these infections unless the organism has been shown to be sensitive. For upper respiratory infections due to group A β-haemolytic Streptococci (including prophylaxis of rheumatic fever), penicillin is the usual drug of choice.
In acute intestinal amoebiasis Frakas may be a useful adjunct to amoebicides.
In severe acne doxycycline may be a useful adjunctive therapy.
Doxycycline is indicated, in adults and children older than 10 years, as chemoprophylaxis for malaria caused by Plasmodium falciparum and, in combination with other antimalarial agents, against malaria caused by Plasmodium vivax. Doxycycline is only able to suppress malaria caused by Plasmodium vivax. As there are relatively few locations where P. vivax does not coexist to some extent with P. falciparum, it is recommended that doxyxycline should be used routinely with other agents, for example chloroquine.

4.2 Dose and Method of Administration


The usual dosage and frequency of administration of doxycycline differs from that of other tetracyclines. Exceeding the recommended dosage may result in an increased incidence of side effects. Therapy should be continued at least 24 to 48 hours after symptoms and fever have subsided.
Tetracyclines are not the drugs of choice for the treatment of streptococcal infections (see Section 4.1 Therapeutic Indications). However, when used, therapy should be continued for ten days.

Adults, children over 8 years (and > 50 kg).

The usual dose of doxycycline is 200 mg on the first day of treatment (administered as 100 mg every twelve hours) followed by a maintenance dose of 100 mg/day. The maintenance dose may be administered as a single dose or as 50 mg every twelve hours. In the management of more severe infections (particularly chronic infections of the urinary tract), 100 mg every twelve hours is recommended.

Acute uncomplicated gonococcal infections.

100 mg twice daily for five to seven days.
Resistance to tetracyclines is not uncommon amongst gonococci. The use of tetracycline in the treatment of gonorrhoea should, therefore, be accompanied by monitoring of efficacy.

Primary and secondary syphilis.

300 mg/day in divided doses for at least ten days.

Louse borne typhus.

This has been successfully treated with a single oral dose of 100 or 200 mg according to severity.

Prevention of scrub typhus.

200 mg as a single dose.

Children over 8 years (and < 50 kg, without skeletal growth retardation).

The adult dose of 100 mg should be recalculated on a weight basis as 2 mg/kg. (See Section 4.4 Special Warnings and Precautions for Use, Paediatric use.)
Studies to date have indicated that administration of doxycycline at the usual recommended doses does not lead to excessive accumulation of the antibiotic in patients with renal impairment.

Severe acne.

Some efficacy has been demonstrated in some individuals at a dose of 50 mg/day over a period of 12 weeks. No data showing efficacy beyond 12 weeks have been submitted.

Malaria chemoprophylaxis.

100 mg once a day; commencing two days prior to entering malarious areas, while in the malaria area and for two weeks after leaving the malarious area. A maximum of 100 mg daily for eight weeks is recommended, as safety after eight weeks has not been clearly established (see Section 4.1 Therapeutic Indications; Section 5.1 Pharmacodynamic Properties about combination with other antimalarial agents for prophylaxis against P. vivax).

Method of administration.

Administration of adequate amounts of fluid with the tablets is recommended to reduce the risk of oesophageal irritation and ulceration. Morning (rather than late night) dosing may be preferable. As the recumbent posture may delay oesophageal transit of the tablets, the patient should not lie down for some time after taking the tablets. 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. Antacids containing aluminium, calcium or magnesium and preparations containing iron impair absorption and should not be given to patients taking doxycycline.

4.3 Contraindications

Hypersensitivity to any of the tetracyclines. Use in pregnancy and lactation (see Section 4.6 Fertility, Pregnancy and Lactation).
Rare cases of intracranial hypertension have been reported after tetracyclines and oral retinoids such as isotretinoin or etretinate and Vitamin A. Concomitant treatment is therefore contraindicated (see Section 4.8 Adverse Effects (Undesirable Effects)).
The concurrent use of tetracycline and methoxyflurane has been reported to result in fatal renal toxicity (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions).

4.4 Special Warnings and Precautions for Use

Use with caution under the following circumstances.
The use of antibiotics may occasionally result in overgrowth of nonsusceptible organisms, including fungi. If superinfection occurs, the antibiotic should be discontinued and appropriate therapy instituted.
Photosensitivity manifested by an exaggerated sunburn reaction has been observed in some individuals taking tetracyclines. Patients likely to be exposed to direct sunlight or ultraviolet light should be advised that this reaction can occur with tetracycline drugs and treatment should be discontinued at the first evidence of skin erythema.

Concomitant diseases and/or medications.

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.
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.

Long-term treatment.

In long-term therapy, periodic laboratory evaluation of organ systems, including haemopoietic, renal and hepatic studies, should be performed.
If doxycycline is used to treat infections due to group A β-haemolytic streptococci, treatment should continue for at least 10 days.
Antibiotic associated pseudomembranous colitis has been reported with many antibiotics including doxycycline. A toxin produced with Clostridium difficile appears to be the primary cause. The severity of the colitis may range from mild to life threatening. It is important to consider this diagnosis in patients who develop diarrhoea or colitis in association with antibiotic use (this may occur up to several weeks after cessation of antibiotic therapy). 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 (Lomotil), may prolong and/or worsen the condition and should not be used.
Rarely, oesophagitis and oesophageal ulceration have been reported in patients receiving doxycycline tablets. Most of these patients took medication immediately before going to bed. Patients should be instructed to take doxycycline with plenty of water (at least 100 mL), remain upright and not take their treatment before going to bed. Withdrawal of doxycycline and investigation of oesophageal disorder should be considered if symptoms such as dyspepsia or retrosternal pain occur. Caution is required in the treatment of patients with known oesophageal reflux disorders. 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.

Use in hepatic impairment.

Abnormal hepatic function has been reported rarely and has been caused by both the oral and parenteral administration of tetracyclines, including doxycycline.

Use in renal impairment.

The antianabolic action of the tetracyclines may cause an increase in serum urea. Studies to date indicate that this does not occur with the use of doxycycline in patients with impaired renal function.

Use in the elderly.

No data available.

Paediatric use.

As with other tetracyclines, doxycycline forms a stable calcium complex in any bone forming tissue. A decrease in the fibula growth rate has been observed in premature infants given oral tetracycline in doses of 25 mg/kg every six hours. This reaction was shown to be reversible when the drug was discontinued.
Tetracyclines also interfere with tooth development (see Section 4.6 Fertility, Pregnancy and Lactation, Use in pregnancy). The use of the drugs of the tetracycline class, including Frakas, during tooth development may cause permanent discolouration of the teeth (yellow/ grey/ brown). This reaction is more common during long-term use of the drugs but has been observed following repeated short-term courses. Therefore doxycycline should not be used in children younger than 8 years of age unless other drugs are not likely to be effective or are contraindicated.
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.

Effects on laboratory tests.

False elevations of urinary catecholamine levels may occur due to interference with the fluorescence test.

4.5 Interactions with Other Medicines and Other Forms of Interactions

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.
Antacids containing aluminium, calcium or magnesium and preparations containing iron impair absorption and should not be given to patients taking doxycycline.
Since bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid giving tetracycline in conjunction with penicillin.
Plasma levels of doxycycline are reduced by the administration of barbiturates, anticonvulsants (phenytoin, carbamazepine), disodium hydrogen edetate, sodium bicarbonate, sodium lactate, acetazolamide and ethoxzolamide.
There are anecdotal reports that concurrent use of tetracyclines may render oral contraceptives less reliable. Unplanned pregnancy may occur with this combination. A barrier method of contraception should be used while taking doxycycline and for seven days following completion of the course of Frakas.
The concurrent use of tetracyclines and methoxyflurane has been reported to result in fatal renal toxicity.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category D)
Tetracyclines are safe for use during the first 18 weeks of pregnancy, after which they cause discolouration of the baby's teeth.
During the period of mineralisation of a child's teeth (the second and third trimester of pregnancy, the neonatal period and the first 8 years of life) tetracyclines may induce hypoplasia of the enamel and discolouration of the teeth. Tetracyclines also accumulate in the growing skeleton. These products should be avoided during the second and third trimester of pregnancy.
Large doses of tetracyclines have caused acute fatty necrosis of the liver in pregnant women, especially those with pyelonephritis. Large doses of the drug should not be used in pregnant women, or those likely to become pregnant.
Doxycycline appears in the milk of lactating women. It forms a stable calcium complex in any bone forming tissue and a decrease in the fibula growth rate has been observed in premature infants. The use of drugs of the tetracycline class during tooth development may also cause permanent discolouration of the teeth. Doxycycline should not be given to nursing mothers.

4.7 Effects on Ability to Drive and Use Machines

The effects of this medicine on a person's ability to drive and use machines were not assessed as part of its registration.

4.8 Adverse Effects (Undesirable Effects)

Doxycycline is generally well tolerated. Due to its virtually complete absorption, side effects of the lower bowel, particularly diarrhoea, have been infrequent. The following adverse reactions have been observed in patients receiving doxycycline.

More common reactions.


Photosensitive dermatitis, erythematous rash, maculopapular rash, morbilliform rash, pustular rash, urticaria, onycholysis and discolouration of the nails.


Nausea, anorexia, vomiting, dysphagia, diarrhoea, oesophagitis, oesophageal ulceration, abdominal pain, glossitis, black hairy tongue.


Urticaria, exacerbation of systemic lupus erythematosus and Jarisch-Herxheimer reaction has been reported in the setting of spirochete infections treated with doxycycline.


Cholestatic hepatitis, fatty liver degeneration.


Dose related increase in serum urea (see Section 4.4 Special Warnings and Precautions for Use).


Tooth discolouration, enamel hypoplasia.

Nervous system disorders.



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.


Enterocolitis (see Section 4.4 Special Warnings and Precautions for Use), inflammatory lesions (with monilial overgrowth) in the anogenital region, dyspepsia and pseudomembranous colitis (see Section 4.4 Special Warnings and Precautions for Use), C. difficile diarrhoea, hepatotoxicity, hepatitis. Abnormal hepatic function has been reported rarely (< 1/1,000), pancreatitis.


Exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN).


Acute renal failure.


Angioneurotic oedema, anaphylaxis, anaphylactic shock, anaphylactic reaction, anaphylactoid purpura, pericarditis, serum sickness, hypotension, dyspnoea, peripheral oedema, tachycardia, erythema multiforme, drug rash with eosinophilia and systemic symptoms (DRESS).


Phlebitis associated with intravenous administration; leucopenia; thrombocytopenic purpura; increase in prothrombin time; haemolytic anaemia; eosinophilia, neutropenia.

Nervous system.

Malaise, confusion, taste loss, stupor, hypoaesthesia, paraesthesia, somnolence, increased intracranial pressure in infants. In relation to benign intracranial hypertension, symptoms included blurring of vision, scotomata and diplopia. Permanent visual loss has been reported.


Conjunctivitis, periorbital oedema.

Hearing/ vestibular.



Depression, anxiety, hallucination.





Rare reactions.

Retrosternal pain.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at

4.9 Overdose

Tetracyclines, including doxycycline, generally have low toxicity.


Severe toxicity following acute overdosage is unlikely, with nausea and vomiting being the most common effects after ingestion of therapeutic and overdose amounts.


Treatment may include immediate discontinuation of medication, dilution with water or milk and general supportive care. Antacids may be useful in managing gastric irritation. In most cases, gastrointestinal decontamination is not required. Plasma levels are not clinically useful and specific laboratory monitoring is not needed unless otherwise indicated.
In case of an oral overdose with doxycycline, gastric lavage should be considered to remove unabsorbed portions of the substance. Remaining residues of doxycycline should be minimized by administering antacids or calcium or magnesium salt in order to produce nonabsorbable chelates.
Doxycycline is not sufficiently dialyzable. Thus, hemodialysis or peritoneal dialysis is not very effective.
In massive overdose, there is a risk of liver damage sometimes accompanied by pancreatitis.
For information on the management of overdose, contact the Poison Information Centre on 131126 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Doxycycline is a broad spectrum antibiotic synthetically derived from oxytetracycline.

Mechanism of action.


Doxycycline is primarily bacteriostatic and is thought to exert its antimicrobial effect through inhibition of protein synthesis. It is active against a wide range of Gram positive and Gram negative organisms. (See Section 4.1 Therapeutic Indications).

Susceptibility testing.

Drugs in the tetracycline class have closely similar antimicrobial spectra, and cross resistance among them is common. Microorganisms may be considered susceptible if the MIC (minimum inhibitory concentration) is less than 1.0 microgram/mL, and intermediate if the MIC is 1.0 to 5.0 microgram/mL.
A tetracycline disc may be used to determine microbial susceptibility to drugs in the tetracycline class. If the Kirby-Bauer method of disc susceptibility is used, a 30 microgram tetracycline disc should give a zone of at least 19 mm when tested against a tetracycline susceptible bacterial strain.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties


Tetracyclines are readily absorbed though to a varying extent. They are concentrated by the liver in the bile, and excreted in the urine and faeces at high concentrations and in a biologically active form. Doxycycline is virtually completely absorbed after oral administration. Its absorption is not significantly affected by the presence of food or milk. Following a 200 mg dose, normal adult volunteers averaged peak serum levels of 2.6 microgram/mL of doxycycline at two hours decreasing to 1.45 microgram/mL at 24 hours.


The metabolism of doxycycline in the human body has not been investigated. In vitro serum protein binding of doxycycline varies from 23 to 93%.


Excretion of doxycycline by the kidney is about 40% in 72 hours in individuals with normal function (creatinine clearance above 75 mL/minute). This percentage excretion may fall as low as 1 to 5% in 72 hours in individuals with severe renal insufficiency (creatinine clearance below 10 mL/minute). Studies have shown no significant difference in serum half-life of doxycycline (range 18 to 22 hours) in individuals with normal and severely impaired renal function.
The fraction of drug that is not eliminated with urine is mainly excreted in the faeces. More than 90% of an oral dose of doxycycline is eliminated from the body within 72 hours of drug administration.
Haemodialysis does not alter serum half-life.

5.3 Preclinical Safety Data


No data available.


No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

Microcrystalline cellulose, sodium starch glycollate, hydrogenated castor oil, povidone, colloidal silicon dioxide and magnesium stearate.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.
For information about interactions with other medicines and other forms of interactions, see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry can be found on the packaging.

6.4 Special Precautions for Storage

Store below 25°C.
Protect from light.

6.5 Nature and Contents of Container

Frakas tablets are available in PP/Al blister packs of 25 tablets.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Doxycycline is a light yellow crystalline powder, which has a high lipid solubility and a low affinity for calcium binding. It is highly stable in normal human serum. It will not degrade into an epianhydro form.
Chemical formula: (4S,4aR,5S,5aR,6R,12aS)-4- dimethylamino- 1,4,4a,5,5a,6,11,12a- octahydro- 3,5,10,12,12a- pentahydroxy-6-methyl-1,11- dioxonaphthacene-2- carboxamide monohydrate.
Molecular formula: C22H24N2O8.H2O.
Molecular weight: 462.5.

Chemical structure.

CAS number.


7 Medicine Schedule (Poisons Standard)


Summary Table of Changes