13-cis-retinoic acid and bone density

Challenges and Solutions in Oral Isotretinoin in Acne: Reflections on 35 Years of Experience

Acne vulgaris affects more than 80% of adolescents and young adults and forms a substantial proportion of the dermatologist's and general practitioner's caseload. Severity of symptoms varies but may result in facial scarring and psychological repercussions. Oral isotretinoin is highly effective but can only be prescribed by specialists. Side effects are recognized and mostly predictable, ranging from cosmetic effects to teratogenicity. These can affect patients' quality of life and treatment adherence. This article provides a commentary on 4 key areas: the use of oral isotretinoin vs oral antibiotics, including the importance of early recognition of nonresponse to treatment, the psychological effects of acne and isotretinoin treatment, the side effects of isotretinoin therapy, and cosmetic treatment options that can help alleviate predictable side effects. The authors, who have all participated in various international expert groups, draw on relevant literature and their extensive professional experience with oral isotretinoin in the treatment of acne. The aim of this article is to provide an informative and practical approach to managing oral isotretinoin treatment in patients with acne, to help optimize treatment of this skin disease.

The safety of isotretinoin treatment in patients with bone fractures

Isotretinoin is widely applicable in dermatology, although it may develop severe side effects in the skeletal system. An intention of this review was to establish the safety of oral isotretinoin in patients with bone fractures. Both MEDLINE/Pubmed and SCOPUS databases were searched to investigate the influence of isotretinoin on the skeletal system. The drug shows a strong osteoporotic activity in rats whereas this effect is milder in humans. Biochemical markers of bone turnover remain unchanged except for serum calcium in patients receiving a high dose of isotretinoin. An excessive intake of vitamin A may impair functioning of vitamin D especially in people with a vitamin D deficiency, therefore a similar side effect may also occur in patients on isotretinoin treatment. We suggest reducing the use of isotretinoin after bone injury or continuing the treatment at low dosing with a concomitant correction of vitamin D and calcium status.

Isotretinoin updates

Acne vulgaris is a chronic inflammatory disease of pilosebaceous follicles commonly affecting adolescents and young adults. This disease has a profound psychological impact on affected individuals and treatment has been shown to significantly improve both self-esteem and quality of life. Isotretinoin is an effective medication used primarily in severe cystic acne patients. Over the past 30 years, this medication has revolutionized the treatment of acne. However, despite its popularity there are numerous side effects associated with its use. Most of its side effects are predictable and dose dependent, which has led to the development of variable dose regimens. Unfortunately, rare but significant side effects (e.g., depression, inflammatory bowel disease) do occur and necessitate careful monitoring to improve clinical outcomes and minimize potential adverse events.

Therapeutic hotline. Does isotretinoin have effect on vitamin D physiology and bone metabolism in acne patients?

Isotretinoin is an effective therapy for severe nodulocystic acne. Several experimental studies suggest that it may have an effect on vitamin D physiology. In the present study, the authors aimed to investigate the effect of isotretinoin treatment on the metabolism of vitamin D in acne patients. A prospective analysis of 50 consecutive acne patients who were treated with isotretinoin for 3 months was done. Before and after 3 months of treatment, 25 hydroxy vitamin D, 1,25 dihydroxy vitamin D, and bone alkaline phosphatase, calcium, phosphate, and parathormone levels were measured. The 25 hydroxy vitamin D and serum calcium levels decreased significantly (p < 0.0001, p < 0.05, respectively), whereas 1,25 dihydroxy vitamin D, parathormone, and bone alkaline phosphatase levels increased significantly after 3 months of isotretinoin treatment (p < 0.005, p < 0.005, p < 0.0001, respectively). Aspartate aminotransferase, total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels also increased significantly after isotretinoin treatment. This prospective clinical study showed that isotretinoin has an effect on vitamin D metabolism. Further clinical studies with longer periods of follow-up are needed to understand the effect of isotretinoin on vitamin D and bone metabolism.

Bone mineral density and bone turnover markers in patients receiving a single course of isotretinoin for nodulocystic acne

BACKGROUND

High-dose isotretinoin has been reported to have adverse effects on bone mineral density (BMD); however, studies evaluating changes in BMD with isotretinoin therapy at different dosages and with varying treatment durations have produced conflicting results.

OBJECTIVE

To investigate the effect of a standard, single course of isotretinoin therapy on BMD and bone turnover markers in patients with nodulocystic acne.

METHODS

Thirty-six patients (15 male, 21 female) with severe, recalcitrant, nodulocystic acne and 36 healthy controls (16 male, 20 female) were enrolled in the study. Patients received isotretinoin treatment for 4-6 months until a cumulative dose of 120 mg/kg had been achieved. BMD in the lumbar spine and femur was measured at baseline and at the end of therapy by dual-energy X-ray absorptiometry. Serum calcium, phosphate, parathormone, total alkaline phosphatase, osteocalcin, free deoxypyridinoline, and urinary calcium were also measured before and at the end of treatment.

RESULTS

No significant differences were found in lumbar spine and femoral BMD between the patient and control groups at the beginning of the study (P > 0.05), and no statistically significant difference was observed between the BMD values in patients at the beginning vs. the end of treatment (P > 0.05). No statistically significant difference in bone turnover markers was found between patients and controls at the beginning of the study (P > 0.05), and no statistically significant changes in bone turnover markers were observed in patients at the beginning vs. the end of treatment (P > 0.05).

CONCLUSION

A single course of isotretinoin therapy has no clinically significant effect on bone metabolism.

Lack of significant skeletal changes after long-term, low-dose retinoid therapy: case report and review of the literature

BACKGROUND

Long-term systemic retinoid therapy has been associated with skeletal side effects. There have been reports of diffuse idiopathic skeletal hyperostosis (DISH) syndrome, calcification of ligaments, and osteoporosis, as well as premature fusion of epiphyses and modeling abnormalities of long bones, occurring in patients on chronic high-dose isotretinoin, etretinate, and acitretin therapy. Low-dose acitretin has been used for many years as monotherapy or in combination with other systemic therapies for psoriasis. Evidence to date suggests that the frequency of symptomatic bony effects is quite low in these patients.

OBJECTIVE

To present the radiologic findings of a patient on long-term, low-dose acitretin and etretinate and to review the literature on the radiologic evidence of skeletal side effects during retinoid therapy.

METHODS

Case report and literature search.

RESULTS

A patient on low-dose acitretin had no significant radiologic abnormalities associated with retinoid use after 9 years of treatment. A review of the literature revealed conflicting reports on the incidence of radiologic abnormalities in patients on retinoid treatment.

CONCLUSION

The evidence to date does not substantiate a clear link between radiologic skeletal abnormalities and long-term, low-dose acitretin or etretinate therapy.

Effect of a single course of isotretinoin therapy on bone mineral density in adolescent patients with severe, recalcitrant, nodular acne

BACKGROUND

Adverse changes in bone have been reported for patients undergoing high-dose, long-term (several years) isotretinoin therapy for disorders of cornification. The effect of short-term (4-5 months) therapy at the lower dose recommended for acne on bone development in younger, growing adolescent (12-17 years) patients has not been well studied.

OBJECTIVE

The purpose of the study was to evaluate the effect of a standard, single course of isotretinoin (Accutane) therapy on bone mineral density (BMD) of the lumbar spine and hip in adolescents ages 12 to 17 years with severe, recalcitrant, nodular acne.

METHODS

In this open-label, multicenter study, 217 adolescents (81 girls) with severe, recalcitrant, nodular acne were enrolled and treated with isotretinoin twice daily with food at the recommended total dose of approximately 1 mg/kg for 16 to 20 weeks. BMD in the lumbar spine and hip was measured at baseline and at the end of therapy by dual energy radiograph absorptiometry.

RESULTS

There was no clinically significant mean change in BMD measured at the lumbar spine (+1.4%, range: -4.9% to +12.3%) or total hip (-0.26%, range: -11.3% to +15.0%). Hyperostosis was not observed in any patient. Typical efficacy expected in the treatment of acne was observed.

CONCLUSIONS

A 16- to 20-week course of isotretinoin treatment at the recommended dose for severe acne has no clinically significant effect on lumbar spine and total hip BMD in the adolescent (12-17 years) population.

Effect of fenretinide on bone mineral density and metabolism in women with early breast cancer

Prolonged administration of natural or synthetic retinoids has been associated with significant skeletal abnormalities, including osteoporosis. We studied the effects of the synthetic retinoid fenretinide (N-4-hydroxyphenylretinamide, or 4-HPR) administered for a mean of 40 months on bone mineral density and metabolism in 66 consecutive women with early breast cancer belonging to a secondary prevention trial. The mean (+/-SD) bone mineral density at the distal and ultradistal forearm were, respectively, 0.61+/-0.08 and 0.30+/-0.05 g/cm2 in 33 treated women and 0.62+/-0.07 and 0.29+/-0.07 g/cm2 in 33 control women (p = ns for both). Also, no significant difference was observed in markers of bone formation such as bone alkaline phosphatase and osteocalcin, nor in urinary bone resorption markers such as calcium, hydroxyproline, and type I bone collagen cross-linked N-telopeptide (NTx). However, a border-line higher excretion of urinary calcium and NTx was found in the 4-HPR group after adjustment for menopausal status. We conclude that prolonged administration of 4-HPR is not associated with significant alterations of bone mineral density of the forearm. However, a trend towards an increase in bone resorption markers suggests the need for further assessment at different skeletal sites.