Consumer medicine information

1. Why am I using DUAC ONCE DAILY GEL?

DUAC ONCE DAILY GEL contains the active ingredients clindamycin and benzoyl peroxide. DUAC ONCE DAILY GEL is used to treat acne.
For more information, see Section 1. Why am I using DUAC ONCE DAILY GEL? in the full CMI.

2. What should I know before I use DUAC ONCE DAILY GEL?

Do not use if you have ever had an allergic reaction to DUAC ONCE DAILY GEL or any of the ingredients listed at the end of the CMI.
Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding.
For more information, see Section 2. What should I know before I use DUAC ONCE DAILY GEL? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with DUAC ONCE DAILY GEL and affect how it works.
A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How do I use DUAC ONCE DAILY GEL?

• DUAC ONCE DAILY GEL should be applied once daily in the evening

5. What should I know while using DUAC ONCE DAILY GEL?

6. Are there any side effects?

Side effects which have been reported at the site of application include dry skin, discolouration of skin, skin peeling and pain, itching, burning sensation on skin, sensitivity to sunlight and redness of your skin, especially during the first few weeks of use. Other side effects which have been reported include headache, nausea, vomiting, diarrhoea including bloody diarrhoea and stomach pain.
For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.

1 Name of Medicine

Benzoyl peroxide/ clindamycin phosphate.

2 Qualitative and Quantitative Composition

Duac Once Daily Gel contains clindamycin 1% w/w (as phosphate) and benzoyl peroxide 5% w/w. The product is presented in internally, lacquered membrane-sealed aluminium tubes fitted with a polyethylene screw cap.
Duac Once Daily Gel contains 10 mg/g (1% w/w) clindamycin (as phosphate) and 50 mg/g (5% w/w) benzoyl peroxide.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Duac Once Daily Gel is a white to slightly yellow homogenous gel for topical use.

4 Clinical Particulars

4.9 Overdose

No case of overdosage has been reported.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).
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 Section 4.4 Special Warnings and Precautions for Use).
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 (13 11 26).

5 Pharmacological Properties

5.3 Preclinical Safety Data

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.

6 Pharmaceutical Particulars

6.7 Physicochemical Properties

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.
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).
Chemical formula: C₁₈H₃₄ClN₂O₈PS.
Molecular weight: 504.97.
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.
Chemical name: dibenzoyl peroxide. Molecular formula: C₁₄H₁₀O₄.
Molecular weight: 242.23.
Chemical structure. Clindamycin phosphate.
https://stagingapi.mims.com/au/public/v2/images/fullchemgif/CSCLIPHO.gif Benzoyl peroxide.
https://stagingapi.mims.com/au/public/v2/images/fullchemgif/CSBENPER.gif CAS number. CAS Number: 24729-96-2 - Clindamycin phosphate.
CAS Number: 94-36-0 - Benzoyl peroxide.

7 Medicine Schedule (Poisons Standard)

Schedule 4 - Prescription Only Medicine.

Summary Table of Changes

https://stagingapi.mims.com/au/public/v2/images/fulltablegif/DUACODST.gif