Effects on Calcium Metabolism
In controlled clinical trials with VECTICAL Ointment, among subjects having
laboratory monitoring, hypercalcemia was observed in 24% (18/74) of subjects
exposed to active drug and in 16% (13/79) of subjects exposed to vehicle. However,
the increases in calcium and albumin-adjusted calcium levels were less than
10% above the upper limit of normal.
If aberrations in parameters of calcium metabolism occur, treatment should
be discontinued until these parameters have normalized. The effects of VECTICAL
Ointment on calcium metabolism following treatment durations greater than 52
weeks have not been evaluated. Increased absorption may occur with occlusive
use.
Ultraviolet Light Exposure
Animal data suggest that the vehicle of VECTICAL Ointment may enhance the ability
of ultraviolet radiation (UVR) to induce skin tumors [see Carcinogenesis,
Mutagenesis, Impairment of Fertility]
Subjects who apply VECTICAL Ointment to exposed skin should avoid excessive
exposure of the treated areas to either natural or artificial sunlight, including
tanning booths and sun lamps. Physicians may wish to limit or avoid use of phototherapy
in patients who use VECTICAL Ointment.
Unevaluated Uses
The safety and effectiveness of VECTICAL Ointment in patients with known or
suspected disorders of calcium metabolism have not been evaluated.
The safety and effectiveness of VECTICAL Ointment in patients with erythrodermic,
exfoliative, or pustular psoriasis have not been evaluated.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment of Fertility
When calcitriol was applied topically to mice for up to 24 months, no significant
changes in tumor incidence were observed. Concentrations of calcitriol in ointment
base of 0 (vehicle control), 0.3, 0.6 and 1.0 ppm were evaluated.
A two-year carcinogenicity study was conducted in which calcitriol was orally
administered to rats at dosages of approximately 0.005, 0.03, and 0.1 mcg/kg/day
(0.03, 0.18, and 0.6 mcg/m²/day, respectively). The incidence of benign
pheochromocytomas was significantly increased in female rats. No other significant
differences in tumor incidence data were observed.
In a study in which albino hairless mice were exposed to both ultra-violet
radiation (UVR) and topically applied calcitriol ointment, a reduction in the
time required for UVR to induce the formation of skin tumors was observed in
all groups that received the ointment base, including the vehicle-treated control
group, relative to animals that received no ointment but which were exposed
to UVR. The time required for UVR to induce the formation of skin tumors did
not differ between animals that received plain vehicle and those that received
vehicle that contained calcitriol. Concentrations of calcitriol in ointment
base of 0 (vehicle control), 0.3, 0.6 and 1.0 ppm were evaluated. These data
suggest that the vehicle of VECTICAL Ointment may enhance the ability of UVR
to induce skin tumors.
Calcitriol did not elicit genotoxic effects in the mouse lymphoma TK locus
assay. Studies in which male and female rats received oral doses of calcitriol
of up to 0.6 mcg/kg/day (3.6 mcg/m²/day) indicated no impairment of fertility
or general reproductive performance. Based upon the recommended human dose and
instructions for use, it is not possible to calculate human dose equivalents
for animal exposure in these studies.
Use In Specific Populations
Pregnancy
Teratogenic Effects: Pregnancy Category C.
VECTICAL Ointment contains calcitriol which has been shown to be fetotoxic.
There are no adequate and well-controlled studies for VECTICAL Ointment in pregnant
women. VECTICAL Ointment should be used during pregnancy only if the potential
benefit to the patient justifies the potential risk to the fetus.
Teratogenicity studies with calcitriol were performed in which rats were treated
orally at dosages up to 0.9 mcg/kg/day (5.4 mcg/m²/day) and in which rabbits
received topical application of calcitriol ointment (3 ppm) to 6.4% of the body
surface area. No effects on reproductive or fetal parameters were observed in
rats. In rabbits, topically applied calcitriol induced a significantly elevated
mean post-implantation loss and an increased incidence of minor skeletal abnormalities
due to retarded ossification of the pubic bones. A slightly increased incidence
of skeletal variation (extra 13thrib, reduced ossification of epiphyses)
was also observed. These effects may have been secondary to maternal toxicity.
Based on the recommended human dose and instructions for use, it is not possible
to calculate human dose equivalents for animal exposures in these studies.
Nursing Mothers
It is not known whether calcitriol is excreted in human milk. Because many
drugs are excreted in human milk, caution should be exercised when VECTICAL
Ointment is administered to a nursing woman.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established.
Geriatric Use
Clinical studies of VECTICAL Ointment did not include sufficient numbers of
subjects aged 65 and over to determine whether they respond differently from
younger subjects. Other reported experience has not identified differences in
responses between the elderly and younger patients.
Last updated on RxList: 3/10/2009