THEOPHYLLINE tablet extended release

Country: United States

Language: English

Source: NLM (National Library of Medicine)

Active ingredient:

THEOPHYLLINE ANHYDROUS (UNII: 0I55128JYK) (THEOPHYLLINE ANHYDROUS - UNII:0I55128JYK)

Available from:

Heritage Pharmaceuticals Inc.

INN (International Name):

THEOPHYLLINE ANHYDROUS

Composition:

THEOPHYLLINE ANHYDROUS 300 mg

Prescription type:

PRESCRIPTION DRUG

Authorization status:

Abbreviated New Drug Application

Summary of Product characteristics

THEOPHYLLINE - THEOPHYLLINE TABLET, EXTENDED RELEASE
HERITAGE PHARMACEUTICALS INC.
----------
THEOPHYLLINE EXTENDED-RELEASE TABLETS
RX ONLY
DESCRIPTION
Theophylline is structurally classified as a methylxanthine. It occurs
as a white, odorless, crystalline
powder with a bitter taste. Anhydrous theophylline has the chemical
name 1_H-_Purine -2, 6-dione, 3,7-
dihydro-1, 3-dimethyl-, and is represented by the following structural
formula:
C H N O M.W. 180.17.
This product allows a 12-hour dosing interval for a majority of
patients and a 24-hour dosing interval
for selected patients (see DOSAGE AND ADMINISTRATION section for
description of appropriate
patient populations).
Each extended-release tablet for oral administration contains either
300 mg or 450 mg of anhydrous
theophylline. Tablets also contain as inactive ingredients:
hypromellose, lactose monohydrate,
magnesium stearate and povidone.
CLINICAL PHARMACOLOGY
MECHANISM OF ACTION:
Theophylline has two distinct actions in the airways of patients with
reversible obstruction; smooth
muscle relaxation (i.e., bronchodilation) and suppression of the
response of the airways to stimuli (i.e.,
non-bronchodilator prophylactic effects). While the mechanisms of
action of theophylline are not
known with certainty, studies in animals suggest that bronchodilation
is mediated by the inhibition of two
isozymes of phosphodiesterase (PDE III and, to a lesser extent, PDE
IV) while non-bronchodilator
prophylactic actions are probably mediated through one or more
different molecular mechanisms, that
do not involve inhibition of PDE III or antagonism of adenosine
receptors. Some of the adverse effects
associated with theophylline appear to be mediated by inhibition of
PDE III (e.g., hypotension,
tachycardia, headache, and emesis) and adenosine receptor antagonism
(e.g., alterations in cerebral
blood flow).
Theophylline increases the force of contraction of diaphragmatic
muscles. This action appears to be
due to enhancement of calcium uptake through an adenosine-mediated
channel.
7
8