CADLA increases bone mineralisation
by increasing circulation of
1,25-dihydroxyvitamin D3.
CADLA relieves bone and muscle
pain by decreasing plasma parathyroid
hormone levels and decreases bone
resorption. Treatment of intestinal
calcium malabsorption associated
with postmenopausal, senile and
steroid induced osteoporosis with
CADLA improves the calcium balance.
Alfacalcidol is a precursor of
the active metabolite of vitamin
D, one of the important elements
in the calcium homeostasis. Acting
independently on renal function,
alfacalcidol allow the body itself
to produce the active metabolite
without requiring the formerly
indispensable stage of renal 1
- hydroxylation.
|
Indications: CADLA
is used for treating disturbances
in the calcium metabolism due to
impaired 1-hydroxylation that
happens due to insufficient renal
function, osteoporosis and disorders
related with vitamin D deficiencies
such as:
- Osteoporosis
- Renal osteodystrophy
- Hyperparathyroidism associated
with bone disease
- Idiopathic and postoperative
hypoparathyroidism
- Nutritional and malabsorption
rickets and osteomalacia
- Hypophosphataemic vitamin D resistant
rickets and osteomalacia
- Pseudo deficiency (D Dependent
Type I) rickets with osteomalacia
Contraindications:
CADLA should not be given to patients
with hypercalcemia, hyperphosphataemia
(except due to hypoparathyroidism),
hypermagnesaemia or evidence of
vitamin D toxicity.
Precautions: Throughout the treatment with CADLA
regular serum calcium determinations
are essential.
Drug Interactions: Digitalis Glycosides: Patients
taking digitalis preparations concurrently
with CADLA must be closely monitored
because hypercalcemia in these
patients may lead to cardiac arrhythmias.
Magnesium: Chronic renal dialysis
patients taking magnesium based
antacids along with CADLA must
be closely monitored because
there are chances of hypermagnesaemia
development.
Calcium
and Thiazides: The risk
of hypercalcaemia increases in
patients taking calcium or thiazides
with Alfacalcidol.
Vitamin
D and Derivatives: Alfacalcidol
is a potent derivative of vitamin
D and therefore concurrent administration
should be avoided to eliminate
the risk of hypercalcaemia.
Barbiturates
or Enzyme inducing anticonvulsant
drugs: Patients
taking these drugs requires high
doses of CADLA for desired effects.
Drug
affecting intestinal absorption: Concurrent use of aluminium based
antacids, mineral oil, Cholestyramine
and colestipol may affect the
absorption of CADLA.
Pregnancy: Though animal studies have not
revealed any hazard, CADLA
should only be used during
pregnancy if treatment is essential
and no better alternative is
available.
Lactation: Although not definitely establishment,
it is likely that increased level
of 1, 25- dihydroxy vitamin D3
will be found in breast milk
of mothers treated with CADLA.
This might have some influence
on calcium metabolism of breast
fed infant and discontinuation
of breast feeding should be considered.
Overdosage: Hypercalcemia is treated by stopping
treatment with Alfacalcidol.
Severe hypercalcemia may require
additional treatment with a "loop" diuretic,
intravenous fluids and corticosteriods.
Side Effects: The only side effect of alfacalcidol
treatment is hypercalcaemia.
Hypercalcaemia manifest muscle
fatigue, gastrointestinal disturbances,
thirst, nausea, constipation,
polyuria, muscle pain, join pain.
In dialysis patients with hypercalcaemia
the calcium influx from the dialysis
should be considered.
Dosage & Administration: Initial Dose
Adults and children above 20
kg body weight: 1µg daily Children under
20 kg body weight: 0.05µg/kg/day.
Osteoporosis: 0.5µg/day.
It is important to adjust the dosage according to the biochemical responses
to avoid hypercalcemia. Indices of response include level of serum calcium,
alkaline phosphates, parathyroid hormones, urinary calcium excretion as well
as radiographic and histological investigations. Patients will marked bone
disease may tolerate higher doses without developing hypercalcemia.
However, failure of the serum calcium to rise promptly in osteomalacia patients
does not necessarily mean that a higher dose is required since calcium absorption
may be incorporated into demineralized bone.
Most patients will respond to doses between 1 and 3 mcg daily. The dose requirements
generally decreases in patients with bone disease when there is biochemical
or radiographic evidence of bone healing and in hypoparathyroid patients after
normal serum level have been obtained. Maintenance doses are generally in the
range of 0.5 to 2 mcg daily.
Patients currently taking barbiturate or other anticonvulsant may need larger
doses of CADLA to produce desired effect.
|
