Baclofen

DESCRIPTION

Baclofen is amuscle relaxantand antispastic.

Its chemical name is 4-amino-3-(4-chlorophenyl) butanoic acid. The structural formula is:

C₁₀H₁₂ClNO₂M.W. 213.66

Baclofen USP is a white to off-white, odorless or practically odorless crystalline powder. It is slightly soluble in water, very slightly soluble in methanol and insoluble inchloroform.

Each tablet, for oral administration, contains 10 mg or 20 mg Baclofen. In addition, each tablet contains the following inactive ingredients: colloidalsilicondioxide, microcrystalline cellulose, magnesium stearate,potatostarch, povidone.

INDICATIONS

Baclofen tablets, USP are useful for the alleviation of signs and symptoms ofspasticityresulting frommultiple sclerosis, particularly for the relief of flexor spasms and concomitant pain, clonus, andmuscularrigidity.

Patients should have reversible spasticity so that baclofen treatment will aid in restoringresidualfunction. Baclofen tablets, USP may also be of some value in patients withspinal cordinjuries and other spinalcorddiseases.

Baclofen tablets, USP are not indicated in the treatment ofskeletal musclespasm resulting from rheumatic disorders.

The efficacy of baclofen instroke,cerebral palsy, and Parkinson's disease has not been established and, therefore, it is not recommended for these conditions.

DOSAGE AND ADMINISTRATION

The determination of optimal dosage requires individual titration. Start therapy at a low dosage and increase gradually until optimum effect is achieved (usually between 40-80 mg daily).

The following dosage titration schedule is suggested:

5 mgt.i.d.for 3 days

10 mg t.i.d. for 3 days

15 mg t.i.d. for 3 days

20 mg t.i.d. for 3 days

Thereafter additional increases may be necessary but the total daily dose should not exceed a maximum of 80 mg daily (20 mg q.i.d.).

The lowest dose compatible with an optimal response is recommended. If benefits are not evident after a reasonable trial period, patients should be slowly withdrawn from the drug (See警告,Abrupt Drug Withdrawal).

HOW SUPPLIED

Baclofen Tablets, USP 5 mgare available as a White to off white, round flat-faced, beveled edge tablets debossed with “023” on one side and plain on other side, containing 5 mg baclofen USP packaged in bottles of 100 tablets.

NDC72888-009-01 100s count

Baclofen Tablets, USP 10 mgare available as a White to off white, round flat-faced, beveled edge tablets debossed with “024” on one side and score on other side, containing 10 mg baclofen USP packaged in bottles of 100, 500 and 1000 tablets.

NDC72888-010-01 100s count
NDC72888-010-05 500s count
NDC72888-010-00 1000s count

Baclofen Tablets, USP 20 mgare available as a White to off white, round flat-faced, beveled edge tablets debossed with “025” on one side and score on other side, containing 20 mg baclofen USP packaged in bottles of 100, 500 and 1000 tablets.

NDC72888-011-01 100s count
NDC72888-011-05 500s count
NDC72888-011-00 1000s count

PHARMACIST: Dispense in a well closed container as defined in the USP, with a child-resistant closure (as required).

Store at 20° to 25°C (68°to 77°F) [SeeUSP Controlled Room Temperature].

KEEP THIS AND ALL MEDICATIONS OUT OF THE REACH OF CHILDREN.

Distributed by: Advagen Pharma Ltd, 666 Plainsboro Road, Plainsboro Suite 605, Plainsboro, NJ, 08536, USA. Manufactured by: Rubicon Research Private Limited, Ambernath, Dist: Thane, 421506. Revised: Aug 2019

SIDE EFFECTS

The most common is transient drowsiness (10 to 63%). In one controlled study of 175 patients, transient drowsiness was observed in 63% of those receiving baclofen compared to 36% of those in the placebo group. Other common adverse reactions are dizziness (5 to 15%), weakness (5 to 15%) and fatigue (2 to 4%).

Others Reported

Neuropsychiatric:Confusion (1 to 11%), headache (4 to 8%), insomnia (2 to 7%); and, rarely,euphoria, excitement, depression, hallucinations,paresthesia, muscle pain,tinnitus, slurred speech, coordination disorder,tremor, rigidity,dystonia,ataxia, blurred vision,nystagmus,strabismus,miosis,mydriasis,diplopia,dysarthria, epilepticseizure.

Cardiovascular:Hypotension(0 to 9%). Rare instances ofdyspnea, palpitation, chest pain,syncope.

Gastrointestinal:Nausea (4 to 12%), constipation (2 to 6%); and rarely,dry mouth,anorexia, taste disorder, abdominal pain, vomiting, diarrhea, and positive test foroccult血凳子.

Genitourinary:Urinary frequency (2 to 6%); and rarely,enuresis, urinary retention,dysuria,impotence, inability toejaculate,nocturia,hematuria.

Other:Instances of rash,pruritus,ankleedema, excessiveperspiration, weight gain,nasalcongestion.

Some of the CNS andgenitourinarysymptoms may be related to the underlying disease rather than to drug therapy. The following laboratory tests have been found to be abnormal in a few patients receiving baclofen: increasedSGOT, elevated alkaline phosphatase, and elevation of blood sugar.

DRUG INTERACTIONS

No Information provided

警告

1. Abrupt Drug Withdrawal: Hallucinations and seizures have occurred on abrupt withdrawal of baclofen. Therefore, except for serious adverse reactions, the dose should be reduced slowly when the drug is discontinued.
2. 肾功能受损:因为巴氯芬是第一的rily excreted unchanged through the kidneys, it should be given with caution, and it may be necessary to reduce the dosage.
3. Stroke: Baclofen has not significantly benefited patients with stroke. These patients have also shown poor tolerability to the drug.
4. Pregnancy: Baclofen has been shown to increase the incidence of omphaloceles (ventralhernias) in fetuses of rats given approximately 13 times the maximum dose recommended for human use, at a dose which caused significant reductions in food intake and weight gain in dams. This abnormality was not seen in mice or rabbits.

There was also an increased incidence of incomplete sternebralossificationin fetuses of rats given approximately 13 times the maximum recommended human dose, and an increased incidence of unossifiedphalangealnucleiof forelimbs and hindlimbs in fetuses of rabbits given approximately 7 times the maximum recommended human dose. In mice, noteratogeniceffects were observed, although reductions in mean fetal weight with consequent delays in skeletal ossification were present when dams were given 17 and 34 times the human daily dose. There are no studies in pregnant women. Baclofen should be used during pregnancy only if the benefit clearly justifies the potential risk to the fetus.

PRECAUTIONS

Because of the possibility of sedation, patients should be cautioned regarding theoperationof automobiles or other dangerous machinery, and activities made hazardous by decreased alertness. Patients should also be cautioned that thecentral nervous systemeffects of baclofen may be additive to those of alcohol and other CNS depressants.

Baclofen should be used with caution where spasticity is utilized to sustain uprightpostureand balance inlocomotionor whenever spasticity is utilized to obtain increased function.

In patients withepilepsy, the clinical state andelectroencephalogramshould be monitored at regular intervals, since deterioration in seizure control andEEGhave been reported occasionally in patients taking baclofen.

It is not known whether this drug is excreted in human milk. As a general rule, nursing should not be undertaken while a patient is on a drug since many drugs are excreted in human milk.

A dose-related increase in incidence ofovariancystsand a less marked increase in enlarged and/orhemorrhagicadrenal glands was observed in female rats treated chronically with baclofen.

Ovarian cysts have been found by palpation in about 4% of the multiplesclerosispatients that were treated with baclofen for up to one year. In most cases these cysts disappeared spontaneously while patients continued to receive the drug. Ovarian cysts are estimated to occur spontaneously in approximately 1% to 5% of the normal female population.

Pediatric Use

Safety and effectiveness in pediatric patients below the age of 12 years have not been established.

OVERDOSE

Signs and Symptoms:Vomiting, muscularhypotonia, drowsiness,accommodationdisorders, coma,respiratory depressionand seizures.

Treatment:In the alert patient, empty the stomach promptly by inducedemesisfollowed by lavage. In theobtundedpatient, secure the airway with a cuffedendotracheal tubebefore beginning lavage (do not induce emesis). Maintain adequate respiratory exchange, do not use respiratory stimulants.

CONTRAINDICATIONS

Hypersensitivity to baclofen.

CLINICAL PHARMACOLOGY

The precise mechanism of action of baclofen is not fully known. Baclofen is capable of inhibiting both monosynaptic and polysynaptic reflexes at the spinal level, possibly by hyperpolarization ofafferentterminals, although actions at supraspinal sites may also occur and contribute to its clinical effect. Although baclofen is ananalogof the putative inhibitoryneurotransmittergamma-aminobutyric acid(GABA), there is no conclusive evidence that actions on GABA systems are involved in the production of its clinical effects. In studies with animals baclofen has been shown to have general CNS depressant properties as indicated by the production of sedation with tolerance,somnolence, ataxia, and respiratory andcardiovasculardepression. Baclofen is rapidly and extensively absorbed and eliminated. Absorption may be dose-dependent, being reduced with increasing doses. Baclofen is excreted primarily by the kidney in unchanged form and there is relatively large intersubject variation in absorption and/or elimination.

PATIENT INFORMATION

No information provided. Please refer to the警告ANDPRECAUTIONSsection.