INDICATIONS
Didronel is indicated for the treatment of symptomatic
Paget’s disease of bone and in the prevention and
treatment of heterotopic ossification following total
hip replacement or due to spinal cord injury. Didronel
is not approved for the treatment of osteoporosis.
Paget’s Disease
Didronel is indicated for the treatment of symptomatic
Paget’s disease of bone. Didronel therapy usually
arrests or significantly impedes the disease process as
evidenced by:
- Symptomatic relief, including decreased pain and/or
increased mobility (experienced by 3 out of 5 patients).
- Reductions in serum alkaline phosphatase and urinary
hydroxyproline levels (30% or more in 4 out of 5 patients).
- Histomorphometry showing reduced numbers of osteoclasts
and osteoblasts, and more lamellar bone formation.
- Bone scans showing reduced radionuclide uptake at
pagetic lesions.
In addition, reductions in pagetically elevated cardiac
output and skin temperature have been observed in some patients.
In many patients, the disease process will be suppressed
for a period of at least 1 year following cessation of
therapy. The upper limit of this period has not been determined.
The effects of the Didronel treatment in patients with
asymptomatic Paget’s disease have not been studied.
However, Didronel treatment of such patients may be warranted
if extensive involvement threatens irreversible neurologic
damage, major joints, or major weight-bearing bones.
Heterotopic Ossification
Didronel is indicated in the prevention and treatment
of heterotopic ossification following total hip replacement
or due to spinal cord injury.
Didronel reduces the incidence of clinically important
heterotopic bone by about two-thirds. Among those patients
who form heterotopic bone, Didronel retards the progression
of immature lesions and reduces the severity by at least
half. Follow-up data (at least 9 months posttherapy) suggest
these benefits persist.
In total hip replacement patients, Didronel does not
promote loosening of the prosthesis or impede trochanteric
reattachment.
In spinal cord injury patients, Didronel does not inhibit
fracture healing or stabilization of the spine.
DOSAGE AND ADMINISTRATION
Didronel should be taken as a single, oral dose. However,
should gastrointestinal discomfort occur, the dose may
be divided. To maximize absorption, patients should avoid
taking the following items within two hours of dosing:
- Food, especially food
high in calcium, such
as milk or milk
products.
- Vitamins with mineral
supplements or antacids which are high in metals such as calcium,
iron, magnesium,
or aluminum.
Pager’s Disease
Initial Treatment Regimens: 5 to 10 mg/ kg/ day, not
to exceed 6 months, or 11 to 20 mg/kg/day, not to exceed
3 months.
The recommended initial dose is 5 mg/kg/day for a period
not to exceed 6 months. Doses above 10 mg/kg/day should
be reserved for when 1) lower doses are ineffective or
2) there is an overriding need to suppress rapid bone
turnover (especially when irreversible neurologic damage
is possible) or reduce elevated cardiac output. Doses
in excess of 20 mg/kg/day are not recommended.
Retreatment Guidelines
Retreatment should be initiated only after 1) a Didronel-free
period of at least 90 days and 2) there is biochemical,
symptomatic or other evidence of active disease process.
It is advisable to monitor patients every 3 to 6 months
although some patients may go drug free for extended periods.
Retreatment regimens are the same as for initial treatment.
For most patients the original dose will be adequate for
retreatment. If not, consideration should be given to
increasing the dose within the recommended guidelines.
Heterotopic Ossification
The following treatment regimens have been shown to be
effective:
- Total Hip Replacement Patients: 20 mg/kg/day for 1 month before
and 3 months after surgery
(4 months total).
- Spinal Cord injured Patients: 20 mg/kg/day for 2 weeks followed
by 10 mg/kg/day for 10 weeks (12 weeks total). Didronel therapy
should begin as soon as medically feasible following the injury,
preferably prior to evidence of heterotopic ossification.
Retreatment has not been studied.
HOW SUPPLIED
Didronel is available as 200-m, white, rectangular tablets
with “P & 8" on one face and “402”
on the other.
NDC 0149-0405-60 bottle of 60
400-mg, white, scored, capsule-shaped tablets with “NE”
on one face and "06" on the other.
NDC 0149-0406-60 bottle of 60
Avoid excessive heat (over 104° F or
40° C).
CAUTION: Federal law prohibits dispensing
without prescription.
|
|
