TIZANIDINE tablet

Country: United States

Language: English

Source: NLM (National Library of Medicine)

Active ingredient:

Tizanidine Hydrochloride (UNII: B53E3NMY5C) (Tizanidine - UNII:6AI06C00GW)

Available from:

H.J. Harkins Company, Inc.

INN (International Name):

Tizanidine Hydrochloride

Composition:

Tizanidine 2 mg

Administration route:

ORAL

Prescription type:

PRESCRIPTION DRUG

Therapeutic indications:

Tizanidine tablets are a short-acting drug for the management of spasticity. Because of the short duration of effect, treatment with tizanidine should be reserved for those daily activities and times when relief of spasticity is most important (see DOSAGE AND ADMINISTRATION ). Concomitant use of tizanidine with fluvoxamine or with ciprofloxacin, potent inhibitors of CYP1A2, is contraindicated. Significant alterations of pharmacokinetic parameters of tizanidine including increased AUC, t1/2, Cmax, increased oral bioavailability and decreased plasma clearance have been observed with concomitant administration of either fluvoxamine or ciprofloxacin. This pharmacokinetic interaction can result in potentially serious adverse events (See WARNINGS and CLINICAL PHARMACOLOGY: Drug Interactions ). Tizanidine tablets are contraindicated in patients with known hypersensitivity to tizanidine or its ingredients.

Product summary:

Tizanidine Tablets USP, 2 mgare white to off white, oval, flat, beveled edged tablets embossed with “R179” on one side and “bisecting score” on other side. The tablets are available in bottles of 30, 150, 300 and 1000.            Bottles of 30                           NDC 55111-179-30            Bottles of 150                         NDC 55111-179-15            Bottles of 300                         NDC 55111-179-03            Bottles of 1000                       NDC 55111-179-10        Tizanidine Tablets USP, 4 mg are white to off white, oval, flat, beveled edged tablets embossed with “R180” on one side and “quadrisecting score” on other side. The tablets are available in bottles of 30, 150, 300 and 1000.            Bottles of 30                           NDC 55111-180-30            Bottles of 150                         NDC 55111-180-15            Bottles of 300                         NDC 55111-180-03            Bottles of 1000                       NDC 55111-180-10  Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F) [see USP Controlled Room Temperature].  Dispense in containers with child resistant closure.   Rx Only Manufactured by: Dr. Reddy’s Laboratories Limited Bachepalli – 502 325 INDIA Repacked by: H.J. Harkins Company, Inc. Nipomo, CA 93444

Authorization status:

Abbreviated New Drug Application

Summary of Product characteristics

TIZANIDINE - TIZANIDINE TABLET
H.J. HARKINS COMPANY, INC.
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TIZANIDINE TABLETS USP
DESCRIPTION
Tizanidine hydrochloride USP, is a centrally acting α -adrenergic
agonist. Tizanidine HCl USP
(tizanidine) is a white to off-white, fine crystalline powder, which
is odorless or with a faint
characteristic odor. Tizanidine is slightly soluble in water and
methanol; solubility in water decreases
as the pH increases. Its chemical name is
5-chloro-4-(2-imidazolin-2-ylamino)-2,1,3-benzothiodiazole
hydrochloride. Tizanidine’s molecular formula is C H ClN S.HCl, its
molecular weight is 290.2 and
its structural formula is:
Tizanidine tablets USP, is supplied as 2 mg and 4 mg tablets for oral
administration. Tizanidine tablets
USP, are composed of the active ingredient, tizanidine hydrochloride
USP (2.29 mg equivalent to 2 mg
tizanidine base and 4.58 mg equivalent to 4 mg tizanidine base), and
the inactive ingredients, anhydrous
lactose, microcrystalline cellulose, colloidal silicon dioxide and
stearic acid.
CLINICAL PHARMACOLOGY
MECHANISM OF ACTION
Tizanidine is an agonist at α -adrenergic receptor sites and
presumably reduces spasticity by increasing
presynaptic inhibition of motor neurons. In animal models, tizanidine
has no direct effect on skeletal
muscle fibers or the neuromuscular junction, and no major effect on
monosynaptic spinal reflexes. The
effects of tizanidine are greatest on polysynaptic pathways. The
overall effect of these actions is
thought to reduce facilitation of spinal motor neurons.
The imidazoline chemical structure of tizanidine is related to that of
the anti-hypertensive drug
clonidine and other α -adrenergic agonists. Pharmacological studies
in animals show similarities
between the two compounds, but tizanidine was found to have one-tenth
to one-fiftieth (1/50) of the
potency of clonidine in lowering blood pressure.
PHARMACOKINETICS SECTION
Absorption and Distribution
Following oral administration, tizanidine is essentially completely
absorbed. The absolute oral
bioavailability of tizan