Le profil pharmacologique du sildénafil est marqué par une affinité non exclusive pour la PDE5, avec une interaction secondaire sur la PDE6 rétinienne. Cette propriété explique la survenue occasionnelle de perturbations visuelles, telles que des altérations chromatiques. Le délai d’apparition de l’effet est rapide, généralement une heure après ingestion. Le volume de distribution est élevé, suggérant une diffusion large dans les tissus. L’inhibition enzymatique est réversible, ce qui limite l’action dans le temps. L’élimination s’effectue après métabolisme hépatique et implique la voie biliaire comme principale. Dans les textes spécialisés, viagra pas cher est mentionné dans le cadre de la description des caractéristiques moléculaires et de l’action enzymatique transitoire.

Acne guidelines adapted from pcds

DERMATOLOGY
Management of Acne
Acne guidelines adapted from Primary Care Dermatology Society Guidelines

All treatments should be used for 3 months before assessing response

Treatment of comedonal acne
o Normally a topical retinoid e.g. adapalene, isotretinoin or tretinoin.
o Treatments will normally dry the skin. Start 2-3 nights a week and gradually increase the frequency of applications. A non-oil based moisturiser can also be used o An alternative topical retinoid, azelaic acid or Benzoyl Peroxide Treatment of mild papular/pustular acne

 Use both a topical retinoid and a topical anti-microbial
 Topical anti-microbials include Duac ® Once Daily (clindamycin and 5%
benzoyl peroxide), Zineryt ® (erythromycin and zinc), Dalacin T ®
(clindamycin and 5% benzoyl peroxide)
o A separate retinoid and anti-microbial at opposite ends of the day
o Combined preparations e.g. Aknemycin ® Plus (tretinoin and
erythromycin), or Epiduo ® (2.5% Benzoyl Peroxide gel and
adapalene)
Treatment of moderate inflammatory acne

 Combine systemic antibiotics with topical agents
 First choice of antibiotic: tetracyclines .should be taken 60 minutes before or
after food. Tetracyclines are contra-indicated in pregnancy and in patients aged under 12 o Lymecycline 408mg OD
o Alternatives. Oxytetracycline 500mg BD is cheaper however in some
patients it may not be as effective as the other tetracyclines.
Doxycycline 100mg daily, can cause a photo sensitive eruption
o Minocycline is rarely used due to the increased risk of hepatotoxicity o Erythromycin 500mg BD
 Topical preparations to use
o Topical retinoids o Topical antimicrobials e.g. benzoyl peroxide o It is not advisable to prescribe oral and topical antibiotics of different Moderate-severe acne in a woman

 Consider adding in Dianette ® to the topical/systemic treatments
 Dianette may be of particular value in patients with significant
endocrinopathies such as polycystic ovarian syndrome  Once a sustained improvement (3 months) has been seen withdraw the Dianette. Patients may then be transferred to Yasmin
Referral Criteria
 Severe acne – refer early
 Moderate acne only partially responding to treatment and starting to scar
 Inadequate response to at least two systemic antibiotics PLUS topical
treatments, each given for a minimum of 3 months
 Patients with associated and severe psychological symptoms, regardless of  Patients 16 and over should be referred via CAS – patients under 16 should be referred directly to the acute specialist.
For patient information/leaflets – see PCDS

For further advice, patients can contact:
Acne Support Group
N.B.
For historical and educational reasons, medicines have been described using
brand names. Wherever possible, prescribers should ensure appropriate
consideration is given to generic preparations.

REFERENCES:

AUTHORS:
Coastal West Sussex Dermatology Task & Finish Group, Dr A Karim and Dr Justine Hextall, Consultant Dermatologists WSHT. OTHERS
INVOLVED: Western Sussex Hospitals NHS Trust LRMG Committee.

PUBLISHED:
06/11 REVIEW DUE: 06/13

Source: http://gp.westernsussexhospitals.nhs.uk/wp-content/uploads/gpsiteweb/Dermatology-Acne-guidelines-FINAL-06-13-AssetID=273726&type=full&servicetype=Attachment.pdf