Consumer medicine information

Duac Once Daily Gel

Clindamycin; Benzoyl peroxide

BRAND INFORMATION

Brand name

Duac Once Daily Gel

Active ingredient

Clindamycin; Benzoyl peroxide

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Duac Once Daily Gel.

What is in this leaflet?

This leaflet answers some common questions about Duac Once Daily Gel. It does not contain all 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 benefits of you using Duac Once Daily Gel against the risks he expects it may have for you.

If you have any concerns about this medicine, ask your doctor or pharmacist.

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

What is Duac Once Daily Gel and what is it used for?

Duac Once Daily Gel contains clindamycin and benzoyl peroxide.

Clindamycin is an antibiotic, which prevents the growth of bacteria which are involved in acne. Benzoyl peroxide acts to reduce comedones (blackheads and whiteheads). It is also effective at killing the bacteria, which are involved in acne, and makes the skin less oily.

Duac Once Daily Gel is used on the skin to treat acne. It helps to:

  • reduce the bacteria or germs, which are implicated in acne;
  • reduce the number of acne spots;
  • reduce the likelihood of new blackheads and whiteheads from forming; and
  • make your skin less oily.

Your doctor may have prescribed Duac Once Daily Gel for another purpose. Ask your doctor if you have any questions about why Duac Once Daily Gel has been prescribed for you.

Duac Once Daily Gel is for use by adults and adolescents (aged 12 and above) with acne.

Duac Once Daily Gel is not addictive.

Duac Once Daily Gel is only available with a doctor's prescription.

Before you use Duac Once Daily Gel

When you must not use it

Do not use Duac Once Daily Gel:

  • if you have an allergy to Duac Once Daily Gel or any of the ingredients in Duac Once Daily Gel listed at the end of this leaflet.
  • if you have a known sensitivity to benzoyl peroxide, clindamycin or lincomycin.
  • you have or have ever had:
    - regional enteritis (inflammation of the small intestine)
    - colitis (inflammation of the large intestine)
    - ulcerative colitis (inflammation which may be due to the presence of ulcers)
  • antibiotic associated colitis (inflammation which may be associated with the past use of antibiotics) if the packaging is torn or shows signs of tampering.
  • for more than 2 months (kept in the refrigerator at 2°C to 8°C) after the date the pharmacist has dispensed it to you.
    If you use this medicine for more than 2 months after the date the pharmacist has dispensed it to you, it may not work as well.
  • if the expiry date (EXP) printed on the pack has passed.
    If you use this medicine after the expiry date has passed, it may not work as well.

If you are not sure whether you should start taking Duac Once Daily Gel, contact your doctor.

Before you start to use it

Tell your doctor if:

  • you are pregnant or intend to become pregnant.
    Your doctor will discuss the risks and benefits of using Duac Once Daily Gel when pregnant.
  • you are breast-feeding or intend to breast-feed.
    Your doctor will discuss the risks and benefits of using Duac Once Daily Gel when breast-feeding.

Do not apply Duac Once Daily Gel to the breasts before breast-feeding.

Tell your doctor or pharmacist if you have used or taken any other clindamycin or erythromycin containing medicines recently.

If you have not told your doctor about any of the above, tell him before you use Duac Once Daily Gel.

Using other medicines

Tell your doctor if you are using other creams, ointments or lotions or taking any other medicine. This includes any that you buy without a prescription from a pharmacy, supermarket or health food shop.

These include:

  • medicated or abrasive soaps and cleansers;
  • chemical peels; and
  • cosmetic products that have a strong drying effect.

These also include products containing:

  • erythromycin;
  • clindamycin;
  • lincomycin;
  • benzoyl peroxide;
  • tretinoin, isotretinoin or tazarotene;
  • salicylic acid; and
  • alcohol.

These medicines may have a cumulative irritant effect or affect how well Duac Once Daily Gel works. You may need to use different amounts of your medicine or you may need to use different medicines. Your doctor will advise you.

Your doctor and pharmacist may have more information on medicines to be careful with, or avoid while using Duac Once Daily Gel.

How to use Duac Once Daily Gel

It is important to use Duac Once Daily Gel exactly as your doctor has told you.

Directions given to you by your doctor may differ from the information contained in this leaflet.

If you do not understand the instructions on the box, tube or this leaflet, ask your doctor or pharmacist for help.

Wash the affected area thoroughly and rinse with warm water. Lightly pat dry the skin.

Remove make-up thoroughly before applying the gel. After it has dried, you can use a non-greasy make-up.

How to apply Duac Once Daily Gel

Duac Once Daily Gel is for application to the skin only.

A thin film of gel should be applied to all of the area of the skin which has acne, not just the individual spots. As a guide, one fingertip (the amount of gel squeezed from the tube which reaches from the tip of your finger to the first joint) is enough to cover the face, two and one-half fingertips of gel will cover your face and back. If the gel does not rub into your skin easily, you are using too much.

Wash your hands after applying the gel.

The usual dose for Duac Once Daily Gel is apply once daily in the evening.

How long should you use it for

It may take 4-6 weeks before you see the full effects of Duac Once Daily Gel on your acne.

Use Duac Once Daily Gel for as long as your doctor tells you to.

Do not use Duac Once Daily Gel for more than 11 weeks unless your doctor tells you to.

If you use Duac Once Daily Gel less often than you should, it may not work as well and your skin problem may not improve. Using it more often than you should may not improve your skin problem any faster and may cause or increase side effects.

If you are not sure of how long you need to use Duac Once Daily Gel, talk to your doctor.

If you forget to use it

If it is almost time for your next application of Duac Once Daily Gel, skip the application you missed and apply the gel when you are next meant to. Otherwise, use it as soon as you remember, and then go back to using your gel as you would normally.

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

If you have trouble remembering to use your medicine, ask your pharmacist for some hints.

If you swallow it

Immediately telephone your doctor or Poisons Information Centre (In Australia 13 11 26; In New Zealand 0800 POISON or 0800 764 766), or go to casualty at your nearest hospital if you think that you or anyone else may have swallowed Duac Once Daily Gel. Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention. Keep this telephone number handy.

While you are using Duac Once Daily Gel

Things you must do

Tell your doctor(s) who is treating you that you are using Duac Once Daily Gel.

If you feel that Duac Once Daily Gel is not helping your condition, tell your doctor.

Tell your doctor if for any reason, you have not used Duac Once Daily Gel exactly as prescribed.

Otherwise, your doctor may think that it was not effective and change your treatment unnecessarily.

If you become pregnant while using Duac Once Daily Gel, tell your doctor.

If you are breastfeeding while using Duac Once Daily Gel, tell your doctor.

Things you must not do

Do not give Duac Once Daily Gel to anyone else, even if they have the same symptoms as yours.

Things to be careful of

Keep Duac Once Daily Gel away from your lips, eyes, mouth and other mucous membranes. Do not apply to any irritated areas of your skin; for example if you have cuts, grazes, sunburn or eczema.

Be careful not to use too much on your neck or other sensitive areas of the skin.

Avoid excessive exposure to sunlight. Sunlamps should not be used. Avoid using at high altitudes or where the ground is snow-covered. When exposure to sunlight cannot be avoided, use a sunscreen product and wear protective clothing.

Duac Once Daily Gel may bleach hair and coloured fabrics, such as clothing, towels and bed linen. Be careful to avoid contact of Duac Once Daily Gel with hair and coloured fabrics.

Do not use occlusive (air or water tight) dressings on areas treated with Duac Once Daily Gel unless necessary. Using occlusive dressing may increase irritation.

Antibiotics may cause a condition that results in severe diarrhoea and stomach cramps. Although this is unlikely to happen with antibiotics applied to the skin, if you develop stomach cramps or diarrhoea that does not improve or is severe, stop using Duac Once Daily Gel and contact your doctor immediately.

Side effects

Tell your doctor if you do not feel well while you are using Duac Once Daily Gel.

Duac Once Daily Gel helps most people with acne but it may have unwanted side effects in a few people.

All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of these side effects.

Very common side effects:

At site of application:

  • Dry skin
  • Skin peeling
  • Redness of your skin, especially during the first few weeks of use

These side effects are generally mild.

Common side effects:

  • Headache

At the site of application:

  • Skin burning sensation
  • Itching
  • Skin pain
  • Sensitivity to sunlight

Uncommon side effects:

At the site of application:

  • Tingling (paraesthesia)
  • Red, itchy skin, rash (dermatitis, erythematous rash)
  • Worsening of acne

Rare side effects:

  • Allergic reactions
  • nausea, vomiting, diarrhoea, including bloody diarrhoea, stomach pain

At the site of application:

  • Skin reactions, discoloration of the skin
  • Raised itchy rash (hives)

If you suffer severe burning, peeling or itching, or other effects not mentioned in this leaflet, you should stop using Duac Once Daily Gel and go back to your doctor for advice.

After using Duac Once Daily Gel

Storage

Duac Once Daily Gel should be stored in the refrigerator at 2°C to 8°C for up to 2 months. Do not freeze.

Do not leave it in the car, especially the glovebox, or on windowsills. Do not store Duac Once Daily Gel or any other medicine in the bathroom or near a sink.

Heat and dampness can destroy some medicines.

Keep Duac Once Daily Gel where young children cannot reach it.

A locked cupboard at least one and a half metres above the ground is a good place to store medicines.

Disposal

If your doctor tells you to stop using Duac Once Daily Gel or it has passed its expiry date, ask your pharmacist what to do with any that is left over.

Product Description

What it looks like

Duac Once Daily Gel is a white to slightly yellow gel that is available in a 25 gram or 30 gram tube. A 5 gram sample tube is also available from your physician only.

Not all pack sizes may be available.

Ingredients

The active ingredients in Duac Once Daily Gel are clindamycin 1% w/w (as phosphate) and benzoyl peroxide 5% w/w.

Duac Once Daily Gel also contains the following inactive ingredients:

  • carbomer 980
  • dimeticone 100
  • disodium lauryl sulfosuccinate
  • disodium edetate
  • glycerol
  • silicon dioxide
  • poloxamer
  • purified water
  • sodium hydroxide

Supplier

Duac Once Daily Gel is supplied in Australia by:

GlaxoSmithKline Australia Pty Ltd
Level 4
436 Johnston Street
Abbotsford
Victoria 3067
Australia

Duac Once Daily Gel is supplied in New Zealand by:

GlaxoSmithKline NZ Limited
Private Bag 106600
Downtown
Auckland 1143
New Zealand

Australian Registration Number:
AUST R 100707

Date of preparation of this leaflet:
18 October 2016

Duac® is a registered trade mark of Stiefel Laboratories, Inc.

Version 5.0

BRAND INFORMATION

Brand name

Duac Once Daily Gel

Active ingredient

Clindamycin; Benzoyl peroxide

Schedule

S4

 

Name of the medicine

Clindamycin 10 mg/g (1% w/w) (as phosphate) and benzoyl peroxide 50 mg/g (5% w/w).

Excipients.

Carbomer 980, dimethicone 100, disodium lauryl sulfosuccinate, disodium edetate, glycerol, silicon dioxide, poloxamer, purified water and sodium hydroxide.

Description

Clindamycin phosphate.

Chemical name: methyl 7-chloro-6,7,8-trideoxy-6- (1-methyl-trans-4-propyl-L- 2-pyrrolidinecarboxamido)-1- thio-L-threo-α-D-galacto-octopyranoside 2-(dihydrogen phosphate). Molecular formula: C18H34ClN2O8PS. MW: 504.97. CAS: 24729-96-2. Clindamycin phosphate is a water soluble ester of the semisynthetic antibiotic produced by a 7(S)-chloro-substitution of the 7(R)-hydroxyl group of the parent antibiotic lincomycin. Synthesis also involves phosphorylation of the C(2)-OH group. It is a white to off white, odourless, hygroscopic, crystalline powder. It is soluble in water, slightly soluble in dehydrated alcohol, very slightly soluble in acetone and in alcohol and practically insoluble in chloroform, methylene chloride and ether.

Benzoyl peroxide.

Chemical name: dibenzoyl peroxide. Molecular formula: C14H10O4. MW: 242.23. CAS: 94-36-0. Benzoyl peroxide is a white amorphous or granular powder with a characteristic odour which is practically insoluble to sparingly insoluble in water, slightly to sparingly soluble in alcohol, soluble in acetone, chloroform and ether and also soluble in methylene chloride with separation of water.

Pharmacology

Clindamycin.

Clindamycin is a lincosamide antibiotic with bacteriostatic action against Gram positive aerobes and a wide range of anaerobic bacteria. Lincosamides such as clindamycin bind to the 23S subunit of the bacterial ribosome and inhibit the early stages of protein synthesis. The action of clindamycin is predominantly bacteriostatic, although high concentrations may be slowly bactericidal against sensitive strains.
Although clindamycin phosphate is inactive in vitro, rapid in vivo hydrolysis converts this compound to the antibacterial active clindamycin. Clindamycin activity has been demonstrated clinically in comedones from acne patients at sufficient levels to be active against most strains of Propionibacterium acnes. Clindamycin in vitro inhibits all Propionibacterium acnes cultures tested (minimum inhibitory concentration (MIC) 0.4 microgram/mL). Free fatty acids on the skin have been decreased from approximately 14 to 2% following application of clindamycin.
Cross resistance may occur between clindamycin and other antibiotics such as lincomycin and erythromycin.
The prevalence of clindamycin resistance may vary geographically and with time for selected species. Local information of resistance is desirable, particularly when treating severe infections.

Resistance development.

Prolonged use of clindamycin may lead to selection of resistant microorganisms and their overgrowth. Duac Once Daily Gel was associated with reduced potential for emergence of resistance to clindamycin in Propionibacterium acnes compared to topical clindamycin alone in a clinical study of short duration.
Cross resistance may occur between clindamycin and other antibiotics such as lincomycin and erythromycin.
The prevalence of clindamycin resistance may vary geographically and with time for selected species. Local information of resistance is desirable, particularly when treating severe infections.
Antibiotic resistant propionibacteria may be transmissible between susceptible individuals. Physicians who routinely palpate patients' skin to assess acne severity should use cross infection control measures to avoid transferring resistant isolates between patients.

Benzoyl peroxide.

Benzoyl peroxide is keratolytic, acting against comedones at all stages of their development. It is an oxidising agent with bactericidal activity against Propionibacterium acnes, the organism implicated in acne vulgaris. Furthermore it is sebostatic, counteracting the excessive sebum production associated with acne.
Duac Once Daily Gel has a combination of keratolytic and antibacterial properties, providing activity against all the inflamed and noninflamed lesions of mild to moderate acne vulgaris.
Duac Once Daily Gel was associated with reduced potential for emergence of resistance to clindamycin in Propionibacterium acnes compared to topical clindamycin alone in a clinical study of short duration.
The presentation of both active ingredients in one product is more convenient and ensures patient compliance.

Pharmacokinetic properties.

Clindamycin.

In a maximised percutaneous absorption study, the mean plasma clindamycin levels during a four week dosing period for Duac Once Daily Gel were negligible (0.043% of applied dose).
The presence of benzoyl peroxide in the formulation did not have an effect on the percutaneous absorption of clindamycin.

Benzoyl peroxide.

Benzoyl peroxide is absorbed by the skin where it is metabolised to benzoic acid. Benzoic acid is mostly conjugated to form hippuric acid, which is excreted via the kidneys. Benzoic acid, too, has a wide margin of safety, and is an approved food additive.
In vivo data obtained with radiolabel procedures on urine specimens from rhesus monkeys indicated about 1.9% of the dose enters systemic circulation as benzoic acid.

Clinical Trials

In five randomised double blind clinical studies of 1319 patients with facial acne vulgaris with both inflammatory and noninflammatory lesions, 397 used Duac Once Daily Gel, 396 used benzoyl peroxide, 349 used clindamycin and 177 used vehicle. Treatment was applied once daily for eleven weeks and patients were evaluated and lesions counted at 2, 5, 8 and 11 weeks.
Against inflammatory lesions, Duac Once Daily Gel was significantly more effective than clindamycin alone in four of five studies and to benzoyl peroxide alone in three of five studies. Against noninflammatory lesions, Duac Once Daily Gel was significantly better than clindamycin in four of five studies. Against noninflammatory lesions, Duac Once Daily Gel was significantly better than benzoyl peroxide in only one of five studies.
Overall improvement was assessed by the physician, and was significantly better with Duac Once Daily Gel than with either benzoyl peroxide or clindamycin alone in three of five studies. Table 1 reports results from the pivotal clinical study.

Indications

Topical treatment of comedo, papular and pustular acne vulgaris.

Contraindications

Duac Once Daily Gel is contraindicated in patients who have demonstrated hypersensitivity to lincomycin, clindamycin, benzoyl peroxide or any components of the formulation; patients with, or with a history of regional enteritis, ulcerative colitis, or antibiotic associated colitis (including pseudomembranous colitis).

Precautions

Hypersensitivity reaction.

If the patient experiences a reaction that indicates contact hypersensitivity or severe irritation, treatment with Duac Once Daily Gel should be discontinued immediately.
For dermatological (external) use only. Contact with the mouth, eyes, lips, other mucous membranes or areas of irritated or broken skin should be avoided. Application to sensitive areas of skin should be made with caution. In case of accidental contact, rinse well with water.
If excessive dryness or peeling occurs, frequency of application should be reduced or application temporarily interrupted.
Patients should be advised that excessive application will not improve efficacy, but may increase the risk of skin irritation.
During the first weeks of treatment, an increase in peeling and reddening may occur (see Adverse Effects). Depending upon the severity of these side effects, patients can use a moisturiser, temporarily reduce the frequency of application of Duac Once Daily Gel or temporarily discontinue use; however, efficacy has not been established for less than once daily dosing frequencies.
Concomitant topical acne therapy should be used with caution because a possible cumulative irritancy may occur, which sometimes may be severe, especially with the use of peeling, desquamating, or abrasive agents.
If severe local irritancy (e.g. severe erythema, severe dryness and itching, severe stinging/burning) occurs, Duac Once Daily Gel should be discontinued.
The irritation potential of the agent may be increased if applied under occlusion.

Photosensitivity.

As benzoyl peroxide may cause increased sensitivity to sunlight, sunlamps should not be used and deliberate or prolonged exposure to sunlight should be avoided or minimised. When exposure to strong sunlight cannot be avoided, patients should be advised to use a sunscreen product and wear protective clothing.
If a patient has sunburn, this should be resolved before using Duac Once Daily Gel.
The product may bleach hair and coloured or dyed fabrics. Avoid contact with hair, fabrics, furniture or carpeting.
Patients should be advised that, in some cases, 4-6 weeks of treatment may be required before the full therapeutic effect is observed.

Pseudomembranous colitis.

Oral and parenteral clindamycin have been associated with severe diarrhoea and pseudomembranous colitis and may range in severity, with an onset of up to several weeks following cessation of therapy. Although this is unlikely to occur with topically applied clindamycin/ benzoyl peroxide, if prolonged or significant diarrhoea occurs or the patient experiences abdominal cramps, treatment should be discontinued immediately and the patient investigated further, as the symptoms may indicate antibiotic associated colitis. Suitable diagnostic methods, such as the determination of Clostridium difficile and toxin and, if necessary, colonoscopy should be employed and treatment options for colitis considered.

Resistance.

Prolonged use of clindamycin may lead to selection of resistant microorganisms and their overgrowth. Duac Once Daily Gel is recommended for a maximum duration of 11 weeks. There have been reports of Propionibacterium acnes resistance to clindamycin in the treatment of acne. If acne recurs, and a product containing a topical antibiotic or antiseptic is considered appropriate by their physician, the patient should be retreated with clindamycin 1%/ benzoyl peroxide 5% (Duac Once Daily Gel) to reduce the risk of development of cross resistance to other topical antibiotics.
Local recommendations about antibiotic use and prevalence of clindamycin resistance should be taken into consideration.
Benzoyl peroxide reduces the potential for emergence of organisms resistant to clindamycin (see Pharmacology, Resistance development). Patients with a recent history of systemic or topical clindamycin or erythromycin use are more likely to have pre-existing antimicrobial resistant Propionibacterium acnes and commensal flora.
Cross resistance has been demonstrated between clindamycin and lincomycin. Resistance to clindamycin is often associated with inducible resistance to erythromycin (see Interactions with Other Medicines).
Clindamycin and erythromycin should not be used in combination.
Duac Once Daily Gel may not be adequate for severe nodulocystic acne.

Effects on fertility.

There are no data on the effect of topical clindamycin or benzoyl peroxide on fertility in humans. Fertility was not impaired in male or female rats given benzoyl peroxide by oral gavage at doses up to 500 mg/kg/day, although male testes and epididymis weights were reduced at 1000 mg/kg/day, a dose which greatly exceeds that applied topically. Fertility was not impaired in rats given clindamycin phosphate 300 mg/kg/day in the diet.

Use in pregnancy.

(Category A)
Animal embryofoetal development studies have not been conducted with Duac Once Daily Gel. Administration of benzoyl peroxide by oral gavage to female rats throughout gestation and 3 days postpartum resulted in reduced pup bodyweights at 1000 mg/kg/day, but no pup gross external abnormalities. Reproductive studies have been performed in rats and mice using oral and parenteral doses of clindamycin phosphate up to 300 mg/kg/day and have revealed no evidence of harm to the foetus due to clindamycin. There are no well controlled studies in pregnant women treated with Duac Once Daily Gel.
There are limited data on the use of topical clindamycin or benzoyl peroxide alone in pregnant women. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. No effects during pregnancy are anticipated since systemic exposure to clindamycin and benzoyl peroxide is anticipated to be low.
It is not known whether Duac Once Daily Gel can cause foetal harm when administered to a pregnant woman or can affect reproductive capacity. Duac Once Daily Gel should be used during pregnancy only if the expected benefit justifies the potential risk to the foetus.

Women of childbearing potential.

There are no contraindications in women of childbearing potential who are practising adequate contraception. However, due to the lack of clinical studies in pregnant women, Duac Once Daily Gel should be used with caution when adequate contraception is not being practised.

Use in lactation.

Duac Once Daily Gel has not been studied during breastfeeding.
Percutaneous absorption of clindamycin and benzoyl peroxide is low; however it is not known whether clindamycin or benzoyl peroxide is excreted in human milk after topical application. Oral and parenteral administration of clindamycin has been reported to result in the appearance of clindamycin in breast milk.
Duac Once Daily Gel should be used during lactation only if the expected benefit justifies the potential risk to the infant.
To avoid accidental ingestion by the infant if used during lactation, Duac Once Daily Gel should not be applied to the breast area.

Genotoxicity.

Clindamycin phosphate was negative in assays evaluating the potential to cause gene mutations and chromosomal damage.

Carcinogenicity.

Benzoyl peroxide has been shown to be a tumour promoter and progression agent in a number of animal studies. Studies in mice have shown that benzoyl peroxide does not increase the growth of tumours initiated by UV light. Lifetime (104 week) carcinogencity studies with benzoyl peroxide dermally applied to mice (1%, 5%, 25/15% on approximately 6 cm2) and rats (1.6%, 5%, 15% on approximately 17.5 cm2) showed no evidence of carcinogenicity.
Long term studies in animals to evaluate the carcinogenic potential of Duac Once Daily Gel and clindamycin phosphate have not been performed.
A photocarcinogenicity study, in which hairless albino mice were exposed to a cumulative tumourigenic dose of simulated sunlight, showed that dermal application of Duac Once Daily Gel, for 5 days per week for 40 weeks, caused a statistically significant reduction in the median time to skin tumour onset. A slight reduction was also observed with the gel vehicle only. It is unclear whether these results have any clinical significance. Clinical use of Duac is likely to be much less extensive than that tested in mice.

Effects on ability to drive and use machines.

There have been no studies to investigate the effect of clindamycin/ benzoyl peroxide on driving performance or the ability to operate machinery. A detrimental effect on such activities would not be anticipated from the adverse reaction profile of clindamycin/ benzoyl peroxide.

Interactions

Concomitant topical antibiotics, medicated or abrasive soaps and cleansers, soaps and cosmetics that have a strong drying effect and products with high concentrations of alcohol and/or astringents should be used with caution as a cumulative irritant effect may occur.
No clinical studies have been conducted to assess interactions between Duac Once Daily Gel and other topical medications.
Duac Once Daily Gel should not be used in combination with erythromycin containing products. In vitro studies have shown antagonism between these two antimicrobials.
Oral clindamycin has been shown to have neuromuscular blocking properties that may enhance the action of other neuromuscular blocking agents. This effect is more common at higher doses of clindamycin. Therefore Duac Once Daily Gel should be used with caution in patients receiving such agents.
Concomitant application of Duac Once Daily Gel with tretinoin, isotretinoin and tazarotene may reduce their efficacy and increase irritation. If combination treatment is required, the products should be applied at different times of the day (e.g. one in the morning and the other in the evening).
Using topical benzoyl peroxide containing preparations at the same time as topical sulphonamide containing products may cause skin and facial hair to temporarily change colour (yellow/ orange).

Adverse Effects

Adverse drug reactions (ADRs) are summarised below for topical clindamycin/ benzoyl peroxide as a combination including any additional ADRs that have been reported for the single topical active ingredients, benzoyl peroxide or clindamycin. Adverse drug reactions are listed by MedDRA system organ class and by frequency. Frequencies are defined as: very common (≥ 1/10), common (≥ 1/100 and < 1/10), uncommon (≥ 1/1,000 and < 1/100), rare (≥ 1/10,000 and < 1/1,000) very rare (< 1/10,000).

Clinical trials.

Very common (> 1/10).

Erythema, peeling, dryness.

Common (> 1/100, < 1/10).

Burning sensation, pruritus.

Uncommon (> 1/1000, < 1/100).

Dermatitis, paraesthesia, erythematous rash, worsening of acne.
In addition to the ADRs reported above for Duac Once Daily Gel, in a clinical trial conducted with a topical clindamycin and benzoyl peroxide (1%/3%) gel product, application site photosensitivity reaction was reported commonly.
In addition to the ADRs reported above for Duac Once Daily Gel, in a clinical trial conducted with a topical clindamycin product headache and application site pain were reported commonly.
Adverse events reported in five comparator clinical trials (studies 150, 151, 152, 156 and 158) by treatment arm are presented in Table 2.
Seven cases of diarrhoea were reported: Duac Once Daily Gel (n = 3), clindamycin gel (n = 1) and benzoyl peroxide gel (n = 3). Of the three cases in the Duac Once Daily Gel group, one case was attributed to Escherichia coli food poisoning, which was successfully treated with antibiotics. The other two patients experienced short episodes of mild diarrhoea with no treatment or change in usage of study medication.
Contact sensitivity was reported in a patch test study (study 157) conducted on healthy volunteers. A total of 218 subjects were tested, of whom 18 (8.7%) developed allergic contact dermatitis after three weeks exposure to Duac Once Daily Gel. This incidence is similar to that observed historically (approximately 10%) at the investigative site for products containing benzoyl peroxide. It is anticipated that the incidence of sensitisation in clinical use will be much less than that reported in this study since semiocclusive patching exaggerates any intrinsic effect of topically applied substances to cause contact sensitisation.

Postmarketing data.

Immune system disorders.

Rare: allergic reactions including hypersensitivity and anaphylaxis.

Gastrointestinal disorders.

Rare: colitis (including pseudomembranous colitis), haemorrhagic diarrhoea, diarrhoea, abdominal pain.

Skin and subcutaneous tissue disorders (at site of application).

Rare: urticaria.

General disorders and administration site conditions.

Rare: application site reactions including discoloration.

Dosage and Administration

Duac Once Daily Gel is for topical (external) use only.
Duac Once Daily Gel is recommended for a maximum duration of treatment of eleven weeks.

Adults and adolescents (aged 12 years and above).

Duac Once Daily Gel should be applied as a thin film once daily in the evening, to affected areas after the skin has been thoroughly washed, rinsed with warm water and gently patted dry.
See Precautions, Interactions with Other Medicines and Overdosage for temporary interruptions or discontinuations of the treatment.

Use in children.

The safety and efficacy of Duac Once Daily Gel has not been established in prepubescent children (under 12 years of age), since acne vulgaris rarely presents in this age group.

Overdosage

No case of overdosage has been reported.

Symptoms and signs.

Excessive application of Duac Once Daily Gel may result in severe irritation (e.g. dermatitis, peeling and dryness). In this event, discontinue use and wait until the skin has recovered.
Topically applied benzoyl peroxide is not generally absorbed in sufficient amounts to produce systemic effects.
Excessive application of topically applied clindamycin may result in absorption of sufficient amounts to produce systemic effects (see Precautions).
In the event of accidental ingestion of Duac Once Daily Gel, gastrointestinal adverse reactions similar to those seen with systemically administered clindamycin may be seen (e.g. nausea, vomiting and diarrhoea).

Treatment.

Appropriate symptomatic measures should be taken to provide relief from irritation due to excessive topical application.
Accidental ingestion or application should be managed clinically or as recommended by the Poisons Information Centre (131 126).

Presentation

Gel (white to slightly yellow, homogenous): 5 g*, 25 g, 30 g*, 40 g*, 45 g*, 50 g*, 55 g*, 60 g*, 70 g*: 1's; 6 g: 1's*, 10's (sample) (internally lacquered, membrane sealed aluminium tube, polyethylene screw cap, in carton).
*Not currently marketed in Australia.

Storage

Instructions to the pharmacist.

Store at 2 to 8°C for up to 2 years. (Refrigerate. Do not freeze.)

Instructions to the patient.

Store at 2 to 8°C for up to 2 months. (Refrigerate. Do not freeze.)

Poison Schedule

S4.