A1,
A2,
B,
C1,
C2,
D,
E,
F,
G-H,
I-K,
L,
M,
N,
O,
P1,
P2,
Q-R,
S,
T,
U-V,
W-Z
Calciferol Overdose, Contraindications and Information - Ergocalciferol
Calciferol Overdose, Contraindications and Information - Ergocalciferol
OVERDOSE
The effects of administered vitamin
D can persist for two or more months after cessation of treatment.
Hypervitaminosis D is characterized by:
- Hypercalcemia with anorexia,
nausea, weakness, weight
loss, vague aches and stiffness, constipation,
mental retardation,
anemia, and mild acidosis.
- Impairment of renal
function with polyuria,
nocturia, polydipsia,
hypercalciuria, reversible azotemia,
of irreversible
renal insufficiency
which may result in death.
- Widespread calcification
of the soft tissues,
including the heart, blood vessels, renal
tubules, and lungs. Bone demineralization
(osteoporosis) in adults occurs concomitantly.
- Decline in the average
rate of linear
growth and increased
mineralization of bones in infants and children (dwarfism).
The treatment of
hypervltaminosis D with hypercalcemia
consists in immediate withdrawal of the vitamin,
a low calcium diet,
generous intake of fluids,
along with symptomatic
and supportive treatment. Hypercalcemic crisis
with dehydration, stupor,
coma, and azotemia
requires more vigorous treatment. The first step
should be hydration
of the patient. Intravenous saline
may quickly and significantly increase urinary
calcium excretion. A
loop diuretic (furosemide
or ethacrynic acid) may be given with the saline
infusion to further
increase renal calcium
excretion. Other reported therapeutic
measures include dialysis
or the administration
of citrates, sulfates, phosphates, corticosteroids, EDTA
(ethylenediaminetetrcetic acid), and mithramycin via appropriate
regimens. With appropriate
therapy, recovery
is the usual outcome when no
permanent damage has
occurred. Deaths via renal
or cardiovascular failure have been reported.
The LD50 in animals is unknown. The toxic
oral dose
of ergocalciferol in the dog is 4 mg/kg.
CONTRAINDICATIONS
Ergocalciferol is contraindicated in patients with hypercalcemia,
malabsorption syndrome, abnormal
sensitivity to the
toxic effects of vitamin
D, and hypervitaminosis D.
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