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
Nasalcrom Pharmacology, Pharmacokinetics, Studies, Metabolism - Cromolyn Sodium
Nasalcrom Pharmacology, Pharmacokinetics, Studies, Metabolism - Cromolyn Sodium
CLINICAL PHARMACOLOGY
Gelatin Capsules
In vitro and in vivo animal
studies have shown that cromolyn sodium
inhibits the release
of mediators from sensitized mast cells. Cromolyn sodium
acts by inhibiting the release
of histamine and leukotrienes (SRS-A) from the mast cell.
Cromolyn sodium has
no intrinsic
vasoconstrictor,
antihistaminic
or anti-inflammatory activity.
Cromolyn sodium is poorly
absorbed from the gastrointestinal
tract. No more than 1% of an administered dose
is absorbed by humans after oral administration, the remainder being
excreted in the feces. Very little absorption of cromolyn sodium
was seen after oral administration
of 500 mg by mouth to
each of 12 volunteers. From 0.28 to 0.50% of the administered dose
was recovered in the first 24 hours of urinary
excretion in 3 subjects.
The mean urinary
excretion of an administered
dose over 24 hours in the
remaining 9 subjects was 0.45%.
Capsules for Inhalation, Inhalation Aerosol, and Inhalation
Solution
In vitro and in vivo animal
studies have shown that cromolyn sodium inhibits sensitized
mast cell degranulation
which occurs after exposure to specific
antigens. Cromolyn sodium
acts by inhibiting the release
of mediators from mast cells. Studies show
that cromolyn sodium
indirectly blocks calcium
ions from entering the mast cell, thereby preventing mediator release.
Cromolyn sodium inhibits
both the immediate
and non-immediate bronchoconstrictive reactions to inhaled antigen.
Cromolyn sodium also
attenuates bronchospasm caused by exercise, toluene
diisocyanate, aspirin, cold
air, sulfur dioxide,
and environmental pollutants, at least in some patients - (Inhalation
Aerosol).
Cromolyn sodium has
no intrinsic
bronchodilator
or antihistaminic
activity.
After administration
by inhalation, approximately 8% of the total cromolyn sodium dose
administered is absorbed and rapidly excreted unchanged, approximately
equally divided between urine
and bile. The remainder of the dose
is either exhaled or deposited in the oropharynx, swallowed, and
excreted via the alimentary
tract.
Nasal Solution
In vitro and in vivo animal
studies have shown that cromolyn sodium
inhibits the degranulation
of sensitized mast cells which occurs after exposure
to specific antigens.
Cromolyn sodium inhibits the release
of histamine and SRS-A
(the slow-acting substance of anaphylaxis). Rhinitis induced
by the inhalation
of specific antigens
can be inhibited to varying degrees by pretreatment
with cromolyn sodium nasal solution.
Another activity demonstrated
in vitrois the capacity
of cromolyn sodium to inhibit the degranulation
of non-sensitized rat mast
cells by phospholipase A and the subsequent release
of chemical mediators.
An additional in vitro
study showed that cromolyn sodium
did not inhibit the enzymatic activity of released phospholipase
A on its specific substrate.
Cromolyn sodium has
no intrinsic
bronchodilator, antihistaminic
or anti-inflammatory activity.
Cromolyn sodium is poorly
absorbed from the gastrointestinal
tract. After instillation
of cromolyn sodium nasal
solution, less than
7% of the total dose administered
is absorbed and is rapidly excreted unchanged in the bile
and urine. The remainder of the dose
is expelled from the nose, or swallowed and excreted via
the alimentary tract.
top
