Premature Epiphyseal Closure-There are spontanous reports of premature Epiphyseal Closure in Acne Pts reciving recommended doses of Accutane for Acne. The effect of mutiple courses of Accutane on Epiphyseal Closure is unknown.
Retinoid-Induced epiphyseal plate closure in guinea pigs-Vit A and it derivatives(retinoids) have been known to cause premature epiphyseal closure in humans as a unwanted side effect of chronic tx. The puropose of the present study was to determine if guinea pigs could serve as a animal model of retinoid-induced epiphyseal plate closure, and to utilize this model to study the mechanism. weanling male Hartley guinea pigs were treated ip via osmotic pump for up to 14days w/vechicle or 0.50-5.5mg/kg/day of the retinoic acid receptor(rar)-selective agonist Agn 190121. Histopathological exam of the proximal tibia of AGN 190121-treated guinea pigs revealed dose-dependent disruption of the epiphyseal plate. The natural retinoids all-trans-retinoic acid and 13-cis-retinoic acid also induced epiphyseal closure when admin. by ip injection for 10days. Prominent historical features of retnoid induced epiphyseal closure induced the loss of basophilic staining in the extracllular matrix of epiphyseal plate chondrocytes and invasion of the epipyseal plate by osteoclasts.
Note: You can read the rest of the study about them trying to see if reversible
Retinoid Induced Epiphyseal plate closure in guinea pigs; Stardeven Am,Davies PJ, Chandraratna Ra, Mader Dr, Johnson At, Thomazy,Va
fundam Appl Toxicol. 1996 Nov;34(1):91-8. Department of Biology,Allergan,Inc. Irvine,Ca 92713, Usa.
Isotretinoin effects on bone.
Digiovanna, J.J. 2001. J. Am. Acad. Dermatol. 45(5): S-176-82.
Isotretinoin has demostrated efficacy in wide range of disorders. The benefical effects of the drug, however, are limited by its adverse effects on the bone. Children exposed to high doses are at risk for premature epiphyseal closure, while adults on long term therapy have an increased tendency to depvelop hyperstosis and other changes of the bone. The knowldege of theese effects, in conjunction w/continued survelliance, are necessary for expert mang.& can ensure many years of efficacious tx w/minimal toxicity.
(really who knows really what's consider a high dose in each indvidual)
Here's another one you can look up: Skelatal changes w/chronic istotretinoin and etretinate admin. McGuire J. Lawson JP Dermatologica. 1987; 175 Suppl 1:169-81. Dept of Dermatology, Yale University School of Medcine, New Haven, Conn.
Premature epiphyseal closure is just one bone effect. I wouldn't just be worried about this one especially thoose who take multiple courses or one single high dose, or long term low dose or low dose.
Bone Denstities in Pt Receiving Isotretinoin for Cystic Acne-Leachman,S.A. Insogna,K.L.,Katz, L., Ellison A. and Millstone,L.M. 1999. Acne. Arch. Dermatol. 135(6): 961-965
(this study was done on men age 17-25, reciving only 6 months of accutane) Skelatal
Hyperostosis in patients reciving chronic, very-low dose Isotretinoion.
Tangrea JA KIlcoyne RF, Taylor PR, Helsel WE, Adrianza ME, Hartman AM, Edwards BK, Peck GL.
Arch Dermatol. 1992 Jul;128(7):921-5. Division of Cancer Prevention Control, national Cancer institute, National institues of health, Bethesda, MD.
(This study talks about Hyperostosis in pt on low dose getting similar skeletal changes as someone on high doses)
Greater trochanter enthesopathy: An ex of short course retinoid enthesopahty: A Case report
Dept of Physical Medcine and Rehab, UMDNJ-New Jersy Medical School, West Orange, NJ ETATS-UNIS
So I have many more studies regarding bones. So I will be waiting for the 1 by roche u talk about in 1985...Journal sources please.....