3 replies to this topic

[aikikai]

Hi
I have been using retinol cream for my face for some period, and I use it by night.
As retinol cream is very strong and could have dangerous effects (some strong creams have a lethal dose) if taken orally, I wonder if someone know how much of the topical retinol cream is absorbed by the skin into the body? Would there be a potential risk of getting high levels of retinol into the body via the topical face cream over an extendend period?

Just a thought as I have not seen any discussions or info regarding this.

[Eva Victoria]

Hi
I have been using retinol cream for my face for some period, and I use it by night.
As retinol cream is very strong and could have dangerous effects (some strong creams have a lethal dose) if taken orally, I wonder if someone know how much of the topical retinol cream is absorbed by the skin into the body? Would there be a potential risk of getting high levels of retinol into the body via the topical face cream over an extendend period?

Just a thought as I have not seen any discussions or info regarding this.

Remember that what will determine the amount of actives absorbed is the size of the treated area.
If you use it in a smaller area like your face it'll hardly have any systemic effect.
But even though you would treat your whole body with tretinoin 0,,5 or 0,1% concentration everyday it would still be safe (at this concentration!).

Topical use of Tretinoin have only caused damage in 1 person (Canada in the 70s) who did not follow the recommended dosage and used Retin-A up to 5 times a day for a year. (Even in the sun without protection). It caused skin cancer. It is a well known case and the only one till today tha twe know of. (I'll try to find the study about Retin-A and post it in your thread later).

[Fredrik]

Oral tretinoin (Vesanoid) is used to treat acute promyelocytic leukemia, a form of cancer. Topical use have never been linked to skin cancer in humans, that is just old wives tales. Since topical and systemic retinoids can treat and prevent actinic keratoses they stand a good chance to actually prevent certain forms of skin cancers (progression of pre-malignant lesions).

As to the systemic effects:

"According to data from Allergan Inc., which makes Tazorac (tazarotene gel), the normal, endogenous plasma level of retinoids is 6.6 ng/mL. These retinoids come from food sources such as carrots, red peppers, sweet potatoes, and fish, she said at a meeting sponsored by Skin Disease Education Foundation. Oral isotretinoin raises this level to 862 ng/mL, according to the Accutane package insert. In contrast, tretinoin 0.1% cream raises the endogenous plasma level by only 2.9 ng/mL, tazarotene 0.1% gel by 0.14 ng/mL, and adapalene 0.1% gel (Differin) by 0.04 ng/mL..."

http://www.skinandal...0851-9/fulltext

Edited by Fredrik, 13 November 2008 - 11:03 PM.

[kismet]

I don't get it, why don't the Americans use topical isotretinoin? It would be only natural, because it was the first retinoid developed. This makes it very difficult to get hold of any good data on topical isotretinoin even though it is one of the most popular retinoids in Austria.

Negligible systemic absorption of topical isotretinoin cream: implications for teratogenicity.

Chen C, Jensen BK, Mistry G, Wyss R, Zultak M, Patel IH, Rakhit AK.

Department of Clinical Pharmacology, Hoffmann-La Roche, Inc., Nutley, New Jersey 07110, USA.

The objective of the study was to assess the extent of systemic exposure of retinoic acid metabolites after excessive application of 0.1% isotretinoin cream in patients with photodamaged skin. This was a single-center, open-label, noncomparative, multiple-dose study of isotretinoin cream. Eighteen female patients with photodamaged skin received a 10 g topical application of isotretinoin cream once daily to a surface area of approximately 2,300 cm2 for 42 days. The patients were not allowed to have high vitamin A-containing foods, vitamin A supplements, or concomitant medications during the entire study period. Plasma levels of four retinoic acids (isotretinoin, tretinoin, 4-oxo-isotretinoin, and 4-oxo-tretinoin) were evaluated after 42 days of isotretinoin application and compared with baseline (pretreatment) levels. The mean area under the curve (AUC) in plasma increased by 48% (+/-SE 9.2) and 77% (+/-13) from the 24-hour pretreatment baseline level for isotretinoin and 4-oxo-isotretinoin, respectively, after treatment with excessive amounts of isotretinoin cream, suggesting systemic absorption of isotretinoin cream. This increase in systemic exposure of retinoic acids was less than that reported earlier after the U.S. recommended daily allowance of 5,000 i.u. of vitamin A supplementation (isotretinoin 141 +/- 19% and 4-oxo-isotretinoin 171 +/- 27%). The minimal systemic availability of isotretinoin cream compared with the U.S. recommended daily allowance for vitamin A supplements provides reasonable evidence for lack of its potential teratogenic risk [or any other systemic effect for that matter].