Calcitriol 3 microg/g ointment: an effective and safe addition to the armamentarium in topical psoriasis therapy

High-potency topical corticosteroids are very effective for the treatment of psoriasis, but are associated with a number of cutaneous adverse effects. Vitamin D modulators have emerged as an important alternative to corticosteroids for the long-term topical treatment of psoriasis. Calcitriol 3 microg/g ointment has long been used to treat psoriasis in Europe and is now the only vitamin D3 ointment available for use in the United States (U.S.). Several randomized clinical trials have compared the safety, efficacy, and cosmetic acceptability of calcitriol ointment with other topical psoriasis therapies. In a three-week investigator-blinded study of 25 healthy subjects, calcitriol 3microg/g ointment was associated with markedly less cumulative skin irritation than was calcipotriene ointment. A multicenter, investigator-blinded study of patients with psoriasis found that investigator-rated global improvement of psoriasis symptoms with calcitriol ointment was statistically noninferior to calcipotriene ointment and that calcitriol use produced significantly fewer patients with cutaneous reactions or discomfort. A multicenter clinical trial of patients with psoriasis who had lesions affecting sensitive skin areas found that calcitriol use produced less skin irritation than did calcipotriene and was generally preferred to calcipotriene ointment by patients. Calcitriol was also significantly more effective for the treatment of psoriasis lesions affecting flexural areas. In another study, patients who received calcitriol ointment exhibited improvement in psoriasis symptoms that was similar to the corticosteroid betamethasone propionate, but were much less likely to have relapsed eight weeks after treatment discontinuation. Two clinical studies also suggested that calcitriol is similar in efficacy to short-contact dithranol, but with a lower incidence of skin irritation and staining. Together, the results of these studies demonstrate that calcitriol 3 microg/g ointment is a significant new option for topical therapy of psoriasis. Calcitriol ointment produces improvement in psoriasis symptoms that is generally similar to the improvement attained with other (except for high potency steroid) topical psoriasis therapies, with a low incidence of adverse events.

Efficacy and safety of topical calcitriol 3 microg/g ointment, a new topical therapy for chronic plaque psoriasis

Topical vitamin D modulators are among the most widely used medications for the treatment of psoriasis. Calcitriol, the naturally occurring active form of vitamin D3, has long been used for topical psoriasis therapy in Europe and other parts of the world and was recently approved in the United States. Calcitriol 3 microg/g ointment has been extensively evaluated for the treatment of chronic plaque-type psoriasis and has been shown to be effective, safe and well-tolerated in a number of short-term and long-term clinical trials. Pharmacokinetic studies in patients with psoriasis and healthy control subjects have demonstrated that topical calcitriol ointment produces little systemic absorption of calcitriol and does not alter systemic calcium homeostasis significantly even when applied to approximately one third of the body surface area. Calcitriol ointment is associated with a low rate of cutaneous irritation and does not increase the sensitivity of treated skin to phototoxicity following treatment with ultraviolet treatment. In two randomized, double-blind clinical trials, twice-daily application of calcitriol ointment for eight weeks resulted in clearing or minimal residual psoriasis in approximately 34% of patients, compared with 12% to 22.5% of patients treated with vehicle ointment (P=0.005 in study 1 and P<0.001 in study 2). Calcitriol ointment also significantly improved ratings of individual psoriasis signs and symptoms of plaque elevation, erythema, scaling and pruritus compared to vehicle. In two long-term studies in which patients were treated with calcitriol ointment for a year or longer, calcitriol ointment produced sustained improvement in physician-rated and patient-rated psoriasis severity. Calcitriol ointment was associated with a low risk of adverse events after one year and did not alter laboratory measures of calcium or phosphorus metabolism in a clinically significant manner. The results of these studies suggest that calcitriol 3 microg/g ointment is an effective, safe and well-tolerated topical psoriasis therapy. Calcitriol ointment offers considerable flexibility for use in a variety of monotherapy and combination therapy regimens for patients with psoriasis.

Elocalcitol, a vitamin D3 analog for the potential treatment of benign prostatic hyperplasia, overactive bladder and male infertility

Elocalcitol, which had been under development by BioXell SpA, is a synthetic derivative of vitamin D3 that regulates cell proliferation and apoptosis via its binding to the vitamin D receptor. In preclinical studies, elocalcitol inhibited the androgen-dependent and androgen-independent proliferation of benign prostatic hyperplasia (BPH) cells more potently than finasteride, a 5alpha-reductase inhibitor. In a phase IIb trial in patients with BPH, treatment with elocalcitol resulted in a significantly reduced prostate volume compared with placebo; irritative urinary symptoms (frequency, urgency and nocturia) and urodynamic parameters were comparable to the alpha1-adrenoceptor antagonist tamsulosin. In a phase IIa trial in patients with prostatitis, elocalcitol significantly reduced levels of IL-8 in semen, suggesting improved quality and forward motility of sperm. However, phase IIb trial data from patients with overactive bladder (OAB) were less promising: elocalcitol failed to meet the primary endpoint despite demonstrating good efficacy in a phase IIa trial. Based largely on these disappointing data, BioXell decided to terminate all further clinical development of elocalcitol, including an uncompleted phase IIa trial in patients with male infertility. Given the novel mechanism of action, efficacy profile and improved tolerability of elocalcitol over existing classes of drugs, the compound could have potentially added to the armamentarium in the expanding therapeutic markets of BPH, OAB and male infertility. This possibility appears to have been negated by BioXell's recent decision to terminate all further development of elocalcitol.

Can topical calcipotriol be a treatment alternative in actinic keratoses? A preliminary report

BACKGROUND

Recent research demonstrated that vitamin D, apart from calcium-related actions, has antiproliferative, prodifferentia-tive and immunomodulatory activities.

OBJECTIVE

To determine whether actinic keratoses may benefit from the antiproliferative and prodifferentiative effects of topical vitamin D.

MATERIALS AND METHODS

The study was an investigator-blinded, half-side comparison trial. Patients applied calcipotriol cream to one side and Ultrabase cream as placebo to the other side of the scalp and/or face for 12 weeks. The total number of actinic keratoses (AKs), diameters and total scores of the target lesions were determined at each visit.

RESULTS

Nine patients were included, eight of whom completed the treatment. There was a statistically significant difference between the total number of AKs at baseline and at week 12 on calcipotriol applied side whereas no difference was detected on placebo applied side (p = 0.028 vs p = 1.00). The mean total score of the target lesions reduced significantly at week 12 on calcipotriol side; however, no significant reduction was found on placebo side (p = 0.017 vs p = 0.056). Although side effects were more common on calcipotriol side, the difference was not statistically significant.

CONCLUSION

Topical calcipotriol may show promise in the treatment of actinic keratoses. More studies are needed to confirm its efficacy.

Gemini vitamin D analogues inhibit estrogen receptor-positive and estrogen receptor-negative mammary tumorigenesis without hypercalcemic toxicity

Numerous preclinical, epidemiologic, and clinical studies have suggested the benefits of vitamin D and its analogues for the prevention and treatment of cancer. However, the hypercalcemic effects have limited the use of 1alpha,25(OH)(2)D(3), the hormonally active form of vitamin D. To identify vitamin D analogues with better efficacy and low toxicity, we have tested >60 novel Gemini vitamin D analogues with a unique structure of two side chains for growth inhibition of breast cancer cells. Our initial studies found that some Gemini analogues are 5-15 times more active than 1alpha,25(OH)(2)D(3) in growth inhibition assay. In vivo experiments were designed to study the inhibitory effect of selected Gemini vitamin D analogues against mammary carcinogenesis by using (a) an N-methyl-N-nitrosourea-induced estrogen receptor (ER)-positive mammary tumor model and (b) an MCF10DCIS.com xenograft model of ER-negative mammary tumors. Among vitamin D analogues we tested, Gemini 0072 [1alpha,25-dihydroxy-20S-21(3-trideuteromethyl-3-hydroxy-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-19-nor-cholecalciferol] and Gemini 0097 [1alpha,25-dihydroxy-20R-21(3-trideuteromethyl-3-hydroxy-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-19-nor-cholecalciferol] administration inhibited by 60% the NMU-induced mammary tumor burden compared with the NMU-treated control group, but these compounds were devoid of hypercalcemia toxicity. In an ER-negative xenograft model, Gemini 0097 significantly suppressed tumor growth without hypercalcemia toxicity. We found that the inhibitory effect of Gemini 0097 was associated with an increased level of cyclin-dependent kinase inhibitor p21 and the insulin-like growth factor binding protein 3 in both ER-positive and ER-negative mammary tumors. Our results suggest that Gemini vitamin D analogues may be potent agents for the prevention and treatment of both ER-positive and ER-negative breast cancer without hypercalcemia toxicity.

Iatrogenic hypercalcaemia--a case report

A case of iatrogenic hypercalcaemia in a 63-year-old female presenting with low back pain and tingling and numbness in both lower limbs off and on is presented here along with a brief discussion of literature. The purpose of this case reporting is to highlight how vitamins can be dangerous if prescribed inadvertently.

Treatment of hypocalcemia caused by hypoparathyroidism or pseudohypoparathyroidism with domestic-made calcitriol: a prospective and self-controlled clinical trial

BACKGROUND

Parathyroid hormone deficiency or resistance may cause hypocalcemia with related symptoms and signs. Lifelong treatment of calcium combined with vitamin D or its metabolites is always necessary for these patients. Here we reported a prospective and open-label trial to investigate the efficacy and safety of domestic-made calcitriol in treatment of hypocalcemia caused by hypoparathyroidism or pseudohypoparathyroidism.

METHODS

Twenty-four patients with confirmed hypoparathyroidism or pseudohypoparathyroidism aged (36.5 +/- 11.0) years old were studied. Among them, 16 patients had idiopathic hypoparathyroidism, 2 had pseudohypoparathyroidism and 6 had hypoparathyroidism secondary to cervical surgery. Serum calcium levels were lower than 1.88 mmol/L. Oral calcitriol was administered twice or three times with elemental calcium 1.2 g per day. All patients were followed every 4 weeks throughout the 12-week period. Dose adjustments of calcitriol were based on serum and urinary calcium levels and symptoms of hypocalcemia.

RESULTS

Twenty patients were included by the end of this study. Muscular weakness, cramps, extremity paresthesia, Chovestek's sign and Trousseau's sign were relieved in 76.9%, 100%, 94.4%, 93.3% and 78.9% of patients, respectively. Serum calcium, plasma ionized calcium and serum phosphorus levels were (1.54+/-0.25) mmol/L, (0.64+/-0.10) mmol/L and (2.00+/-0.46) mmol/L at baseline, and reached (2.20+/-0.20) mmol/L, (0.95+/-0.06) mmol/L and (1.68+/-0.25) mmol/L (P<0.01) at the 12th week of treatment, respectively. Eighty percent of patients were assessed as effective and 20% as partly effective. Three, four and eight patients had hypercalciuria at the 4th, 8th and 12th week of treatment, respectively, which were reduced by thiazide diuretics. The final dose of calcitriol was (1.09+/-0.50) microg/d.

CONCLUSIONS

Calcitriol combined with calcium can be used in treatment of hypocalcemia caused by hypoparathyroidism or pseudohypoparathyroidism effectively and safely. Serum and urinary calcium levels should be monitored during the course of the therapy.

Comparing clobetasol propionate 0.05% spray to calcipotriene 0.005% betamethasone dipropionate 0.064% ointment for the treatment of moderate to severe plaque psoriasis

Topical corticosteroids are widely used in the treatment of psoriasis. This study was conducted to compare the efficacy and safety of clobetasol propionate (CP) 0.005% spray to calcipotriene 0.005%-betamethasome diproprionate 0.064% (C-BD) ointment in patients with moderate to severe plaque psoriasis. Assessments were made at baseline, week 2, week 4 (end of treatment) and week 8 (4 weeks posttreatment). An assessment for Overall Disease Severity (ODS) found that 75% of CP spray-treated patients achieved a rating of clear or almost clear after 4 weeks of treatment compared to 45% of C-BD ointment-treated patients (P=.003). Adverse events were reported by less than one-third of patients from each treatment group (31% for CP spray and 33% for C-BD ointment).

Beneficial effects of better control of secondary hyperparathyroidism with paricalcitol in chronic dialysis patients

BACKGROUND

Treatment of secondary hyperparathyroidism (SHPT) with calcitriol is often limited by the occurrence of hypercalcemia, hyperphosphatemia and risk of vascular calcifications. Paricalcitol, a vitamin D analogue with lower calcemic and phosphatemic effects, is successfully utilized in dialysis patients, although some uncertainty remains about the optimal dosage. Amelioration of survival in hemodialysis patients has been correlated to the use of calcitriol and, even better, paricalcitol.

METHODS

We evaluated 1-year treatment with paricalcitol in 12 chronic hemodialysis patients with moderate-severe SHPT previously treated with intravenous calcitriol. Starting dose of paricalcitol was calculated according to the severity of the disease by the formula: intact parathyroid hormone (iPTH)/80, and successive titration performed according to the NKF-DOQI guidelines.

RESULTS

Paricalcitol caused a rapid decrease in serum levels of iPTH with a consistent percentage of values falling below 150 pg/mL in the first months of treatment. Although the occurrence of hypercalcemia was not significantly different between treatment with calcitriol and paricalcitol, a slight but significant increase in mean calcium levels was observed during paricalcitol treatment. A significant amelioration of erythropoiesis and acid-base balance was observed during paricalcitol treatment.

CONCLUSIONS

Paricalcitol efficiently suppresses PTH secretion in dialysis patients with SHPT, with a moderate calcemic, but not a phosphatemic, effect. The dose of paricalcitol calculated as iPTH/80 may cause acute lowering of bone turnover. The improvement of anemia control and the amelioration of acid-base balance are 2 important additive effects of the better control of SHPT that may improve survival of hemodialysis patients.

High-dose calcitriol therapy and progression of cardiac vascular calcifications

BACKGROUND

Dialysis patients show a very high prevalence of cardiovascular complications, affected as they are with abnormal and accelerated vascular calcifications and, eventually, calcium and phosphorous metabolism disorders. Multislice computed tomography (MSCT) provides a reproducible, high-resolution imaging of calcium contained in cardiac arteries, measured by Agatston score. The aim of the present study was to evaluate the influence of high-dose and low-dose calcitriol therapy on the progression of cardiac vascular calcifications in dialyzed patients.

METHODS

We enrolled 36 dialyzed patients in a prospective study, including an interventional period of 12 months and a follow-up period of 12 months. Eighteen protocol patients received intravenous pulses of high-doses calcitriol at the end of dialytic treatment and sevelamer hydrochloride therapy. Control patients received low-dose calcitriol and sevelamer hydrochloride as well. Two MSCT scans were performed: 1 at the start of the study and 1 at the end of follow-up, and Agatston score was calculated at both examinations.

RESULTS

At first examination, protocol patients showed almost the same level of cardiac vascular calcification as control patients. At the second MSCT, statistically significantly higher values of Agatston score were recorded for all patients. Indeed, patients who showed higher baseline values developed worse calcifications as recorded at the end of follow-up, both in the protocol and control group.

CONCLUSIONS

Our data show that baseline level is strongly predictive of vascular calcification progression, and, moreover, there is no association between calcitriol administered doses and the progression of cardiac vascular calcification.

Does vitamin D receptor and calcium receptor activation therapy play a role in the histopathologic alterations of parathyroid glands in refractory uremic hyperparathyroidism?

BACKGROUND AND OBJECTIVES

Vitamin D receptor activation by vitamin D sterols and calcium-sensing receptor stimulation by cinacalcet are the most powerful treatments of secondary hyperparathyroidism. This study was aimed to assess a possible association between histopathologic changes of parathyroid tissue and treatment modality.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Studies were performed on 82 parathyroids of 22 adult white hemodialysis patients undergoing first parathyroidectomy. The type of hyperplasia and the distribution of chief and oxyphil cells, expressed as oxyphil/chief cell ratio, were assessed. Three groups could be studied according to treatment modality: group A consisted of 6 patients who were treated with cinacalcet, intravenous calcitriol, and phosphate binders; group B consisted of 6 patients who were treated with intravenous calcitriol and phosphate binders, and group C consisted of 10 patients who were treated with phosphate binders alone.

RESULTS

Sixty-eight (82.9%) out of 82 glands removed showed nodular hyperplasia. It was more frequent in groups A and B than in group C. A stepwise forward logistic regression model showed that the probability of nodular hyperplasia was higher in patients who were on calcitriol and/or cinacalcet therapy, in female gender and in patients with a higher body mass index. Oxyphil/chief cell ratio also was significantly different among the three groups. Cinacalcet treatment was the only predictor of this ratio.

CONCLUSIONS

An association was found between calcitriol and/or cinacalcet therapy and a high prevalence of nodular hyperplasia, and between cinacalcet therapy and high oxyphil/chief cell ratio. The meaning of the observed associations remains uncertain.

Vitamin D receptor activator selectivity in the treatment of secondary hyperparathyroidism: understanding the differences among therapies

Secondary hyperparathyroidism (SHPT) is a common and serious consequence of chronic kidney disease (CKD). SHPT is a complex condition characterised by a decline in 1,25-dihydroxyvitamin D and consequent vitamin D receptor (VDR) activation, abnormalities in serum calcium and phosphorus levels, parathyroid gland hyperplasia, elevated parathyroid hormone (PTH) secretion, and systemic mineral and bone abnormalities. There are three classes of drugs used for treatment of SHPT: (i) nonselective VDR activators or agonists (VDRAs); (ii) selective VDRAs; and (iii) calcimimetics. The VDRAs act on the VDR, whereas the calcimimetics act on the calcium-sensing receptor. Calcimimetics are commonly used in conjunction with VDRA therapy. By virtue of the differences in their chemical structure, the nonselective and selective VDRAs differ in their effects on gene expression, and ultimately parathyroid gland, bone and intestine function. Medications in all three classes are effective in suppression of PTH; however, clinical studies show that calcimimetics are associated with an unfavourable tolerability profile and hypocalcaemia, whereas nonselective VDRAs, and to a lesser extent selective VDRAs, are associated with dose-limiting hypercalcaemia and hyperphosphataemia. Selective VDRAs also have minimal undesirable effects on calcium absorption in the intestine, and calcium and phosphorus mobilisation in the bone compared with nonselective VDRAs. Calcium load in patients with CKD can lead to vascular calcification, accelerated progression of cardiovascular disease and increased mortality. High serum phosphorus levels are also associated with adverse effects on cardiorenal function and survival. Recent evidence suggests that VDRAs are associated with a survival benefit in CKD patients, with a more favourable effect with selective VDRAs than nonselective VDRAs. Paricalcitol, a selective VDRA, is reported to exert specific effects on gene expression in various cell types that are involved in vascular calcification and the development of coronary artery disease. This article examines the molecular mechanisms that determine selectivity of VDRAs, and reviews the evidence for clinical efficacy, safety and survival associated with the three drug classes used for treatment of SHPT in CKD patients.

Intraperitoneal calcitriol in infants on peritoneal dialysis

BACKGROUND

Calcitriol has long been used as the main therapy in renal osteodystrophy, but the efficacy of the oral route is not always as high as expected.

OBJECTIVE

To asses the safety and efficacy of intraperitoneal calcitriol in infants undergoing peritoneal dialysis (PD).

PATIENTS AND METHODS

PD patients on oral calcitriol therapy, with serum parathyroid hormone (PTH) >1000 pg/mL during the previous 3 months of treatment, were switched to intraperitoneal calcitriol therapy, 1 microg twice per week. Dose was increased to 1 microg three times per week if PTH remained >1000 pg/mL, and was later readjusted. Target PTH was 200-300 pg/mL according DOQI guidelines.

STATISTICS

All results are expressed as mean +/- SE. The Wilcoxon signed rank test was used to evaluate differences in measurements for each pair of values. The confidence interval for differences between population medians was 96.9%. A p value less than 0.05 was considered significant.

RESULTS

Six male children, mean age 17 +/- 3.86 months, completed a 12-month follow-up. Mean pretreatment PTH was 1654 +/- 209 pg/mL. Mean PTH at months 0, 3, 6, 9, and 12 was 1448 +/- 439*, 1277 +/- 723, 910 +/- 704, 582 +/- 282*, and 465 +/- 224* pg/mL, respectively (*p < 0.05). Twelve hypercalcemic and 10 hyperphosphatemic episodes were successfully treated.

CONCLUSION

Infants on PD who fail to respond to oral calcitriol therapy can be safely treated with intraperitoneal administration of active vitamin D.

Improving the outcome of established therapies for osteoporosis by adding the active D-hormone analog alfacalcidol

While in other chronic diseases combined treatment regimens are the rule there is a lack of reported experience or study data on combining different specific drugs to treat osteoporosis. Significant differences in the mode of action (MOA) of the substances to be combined may be important for achieving optimal therapeutic results. Recognising that today bisphosphonates are the leading therapy for osteoporosis we suggest that the active D-hormone analog alfacalcidol with its completely different mechanisms of action could be an interesting combination to improve the therapeutic outcome of the pure antiresoptive action of bisphosphonates. Alfacalcidol is activated by the enzyme 25-hydroxylase in the liver for systemic and in osteoblasts for local D-hormone actions. It possesses a unique pattern of pleiotropic effects on, e.g. gut, bone, pararthyroids, muscle and brain. Alfacalcidol is superior to plain vitamin D (cholecalciferol) because the final kidney activation of the latter is regulated by a negative feedback mechanism. In vitamin D replete patients or patients with impaired kidney function no increased D-hormone action at the target tissues can be achieved. Animal studies and several trials in humans with alendronate plus calcitriol or alfacalcidol proved that the combination induced significantly higher increases of bone mineral density (BMD) than the respective mono-therapies. The results of the 2-year AAC-trial from our group indicate that the combination alendronate and alfacalcidol is also superior in terms of falls, fractures and back pain. From the review of the literature and the own new results we conclude that this combined therapeutic regimen is a very promising option for treating established osteoporosis and propose a differentiated use of alfacalcidol alone or the combination with alendronate in different stages and clinical situations of osteoporosis.

Valproic acid combined with 13-cis retinoic acid and 1,25-dihydroxyvitamin D3 in the treatment of patients with myelodysplastic syndromes

Valproic acid (VPA), an inhibitor of histone deacetylases, inhibits the growth of leukemia cells and induces their differentiation in vitro. In the present study, VPA in combination with two differentiating agents, 13-cis retinoic acid and 1,25-dihydroxyvitamin D3, was given to 19 previously untreated patients with MDS or CMML. Eight patients had to discontinue treatment before week 16 due to toxicity. According to international working group criteria, three patients (16%) responded to treatment. No correlation between VPA serum level, histone acetylation or clinical response was observed.

A phase I pharmacokinetic and pharmacodynamic study of intravenous calcitriol in combination with oral gefitinib in patients with advanced solid tumors

PURPOSE

In preclinical models, calcitriol and the tyrosine kinase inhibitor gefitinib are synergistic and modulate extracellular signal-regulated kinase (Erk) and Akt pathways. Therefore, we conducted a phase I study of calcitriol and gefitinib to determine the maximum tolerated dose (MTD) of this combination.

EXPERIMENTAL DESIGN

Calcitriol was given i.v. over 1 h on weeks 1, 3, and weekly thereafter. Gefitinib was given at a fixed oral daily dose of 250 mg starting at week 2 (day 8). Escalation occurred in cohorts of three patients until the MTD was defined. Pharmacokinetic studies were done for calcitriol and gefitinib. Serial skin biopsies were done to investigate epidermal growth factor receptor (EGFR) pathway pharmacodynamic interactions.

RESULTS

Thirty-two patients were treated. Dose-limiting hypercalcemia was noted in two of four patients receiving 96 mug/wk of calcitriol. One of seven patients developed dose-limiting hypercalcemia at the MTD 74 mug/wk calcitriol dose level. The relationship between calcitriol dose and peak serum calcitriol (C(max)) and systemic exposure (AUC) was linear. Mean (+/-SD) serum calcitriol C(max) at the MTD was 6.68 +/- 1.42 ng/mL. Gefitinib treatment inhibited EGFR, Akt, and Erk phosphorylation in the skin. Calcitriol did not have consistent effects on skin EGFR or its downstream elements. The combination of gefitinib and calcitriol did not modulate tumor EGFR pathway in patients with serial tumor biopsies.

CONCLUSIONS

High doses of weekly i.v. calcitriol can be administered safely in combination with gefitinib. Calcitriol concentrations achieved at the MTD 74 mug calcitriol exceed in vivo concentrations associated with antitumor activity in preclinical models.

Effect of 2-methylene-19-nor-(20S)-1 alpha-hydroxy-bishomopregnacalciferol (2MbisP), an analog of vitamin D, on secondary hyperparathyroidism

Vitamin D analogs are being developed that retain therapeutic effects but are less calcemic and phosphatemic, a concern in CKD patients who are prone to vascular calcification. We tested a new analog of vitamin D, 2MbisP, and found that it suppresses PTH at doses that do not affect serum Ca or P.

INTRODUCTION

Calcitriol is used for the treatment of secondary hyperparathyroidism. However, its use is often limited by the development of hypercalcemia and hyperphosphatemia, an important consideration in patients with chronic kidney disease (CKD) because they are prone to vascular calcification. To minimize this toxicity, structural modifications in the vitamin D molecule have led to the development of calcitriol analogs with selective actions.

MATERIALS AND METHODS

In this study, we compared the effects of 1,25(OH)(2)D(3) and a new analog, 2-methylene-19-nor-(20S)-1 alpha-hydroxy-bishomopregnacalciferol (2MbisP), on the development of secondary hyperparathyroidism and established secondary hyperparathyroidism in uremic rats and on mobilization of calcium and phosphorus from bone in parathyroidectomized rats. The clearance from circulation, half-life, and binding affinities to the vitamin D-binding protein and vitamin D receptor of this compound were also evaluated.

RESULTS

Uremia produced a marked rise in plasma PTH, but treatment every other day for 2 wk with either 1,25(OH)(2)D(3) (4 ng) or 2MbisP (250, 750, 1500, or 3000 ng) suppressed this increase by >50%. The suppression by 1,25(OH)(2)D(3), however, was accompanied by increases in ionized calcium, phosphorus, and the calcium x phosphorus product, whereas these three parameters were unchanged by 2MbisP. The binding affinity of 2MbisP was 10-20 times less for the vitamin D receptor and 1000 times less for the serum vitamin D-binding protein compared with 1,25(OH)(2)D(3). Also, 2MbisP was cleared more rapidly from the circulation (t1/2 = 10 min) than 1,25-(OH)(2)D(3) (t1/2=7-9 h). In parathyroidectomized rats fed calcium-or phosphorus-deficient diets, daily injections of 2MbisP (1500 or 3000 ng), unlike 1,25(OH)(2)D(3) (50 ng), had no effect on calcium or phosphorus mobilization from bone.

CONCLUSIONS

In uremic rats, 2MbisP can suppress PTH at doses that do not affect plasma calcium, phosphorus, and calcium x phosphorus product. This new vitamin D analog may represent an important tool in the treatment of secondary hyperparathyroidism in patients with CKD.

Calcipotriol and betamethasone dipropionate for the treatment of psoriasis: a 52-week study

Psoriasis is a common skin disease affecting 1%-3% of the world's population with significant impacts on quality of life. There is a great need for therapies that are efficacious and safe, not only for the short-term, but also for long-term management. Dovobet/ Daivobet/ Taclonex is a product combining two molecules, calcipotriol and betamethasone dipropionate, that may offer psoriatic patients with an option for maintenance therapy. The efficacy and safety of this combined formulation when used over a 4-week period is well documented. A recent publication in the British Journal of Dermatology discusses the safety of this product when used for 52 weeks.

Calcitriol 3 microg/g ointment in the management of mild to moderate plaque type psoriasis: results from 2 placebo-controlled, multicenter, randomized double-blind, clinical studies

BACKGROUND

Psoriasis is a chronic skin disorder affecting approximately 2% of the US population. Psoriasis may occur anywhere on the body with initial presentation usually seen between 15 and 30 years of age. Calcitriol 3 microg/g ointment has demonstrated good clinical efficacy as well as topical and systemic safety when used to treat psoriasis.

OBJECTIVES

To confirm the efficacy and safety of calcitriol 3 microg/g ointment versus its vehicle in the treatment of subjects with mild to moderate chronic plaque psoriasis.

METHODS

Suitable subjects were randomized to receive either calcitriol 3 microg/g ointment or its vehicle twice daily for up to 8 weeks in 2 multicenter, randomized, vehicle-controlled, double-blind parallel group studies. Efficacy was evaluated through a Global Severity Score dichotomized in success (clear and minimal) or failure. Erythema, plaque elevation, scaling and dermatologic sum score (sum of the scores for erythema, plaque elevation, and scaling), pruritus, and global improvement were also assessed. Routine safety and clinical laboratory parameters, including calcium homeostasis, were evaluated throughout the study.

RESULTS

In total, 839 subjects were included in the 2 studies: 419 patients received calcitriol 3 microg/g ointment and 420 received the vehicle. In both studies, calcitriol 3 microg/g ointment was shown to be significantly more effective than its vehicle, with onset of therapeutic effect seen as early as week 2 and sustained at all subsequent visits. Calcitriol 3 microg/g ointment demonstrated good systemic and local safety profile comparable to its vehicle with no effect on calcium homeostasis.

CONCLUSION

Calcitriol 3 microg/g ointment applied for 8 weeks is effective and safe in the treatment of mild to moderate psoriasis.