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Skeletal Muscle Relaxant/Prescription

OZOBAX DS

OZOBAX DS

Clinical safety rating

caution

Comprehensive clinical and safety monograph for OZOBAX DS (OZOBAX DS).


Mechanism of Action

Baclofen, a gamma-aminobutyric acid (GABA) analog, acts as an agonist at GABA-B receptors in the spinal cord, leading to decreased excitatory neurotransmitter release and reduced muscle spasticity.

What the body does with it

MetabolismHepatic metabolism via deamination; minor CYP450 involvement.
ExcretionRenal: 70-80% unchanged; fecal: 20-30%; biliary: <5%
Half-lifeTerminal elimination half-life is 1.0-1.5 hours in patients with normal renal function; prolonged to 8-12 hours in moderate renal impairment (CrCl 30-50 mL/min) and up to 20-30 hours in severe renal impairment (CrCl <30 mL/min).
Protein binding20-30% bound to serum albumin.
Volume of Distribution0.2-0.3 L/kg; indicates distribution primarily into extracellular fluid.
BioavailabilityOral: 95-100% (well absorbed); intravenous: 100%.
Onset of ActionOral: 0.5-1 hour; peak effect at 1-2 hours.
Duration of Action6-8 hours based on minimum inhibitory concentration (MIC) for susceptible pathogens; prolonged in renal impairment.
Molecular Weight504.6

Classification & Brands

Dosing & administration

Adults: 600 mg orally twice daily; if efficacy not achieved after 2–3 weeks, may increase to 600 mg three times daily.

Dosage formSOLUTION
Renal impairmenteGFR 30–59 mL/min/1.73 m²: 300 mg twice daily. eGFR 15–29 mL/min/1.73 m²: 200 mg twice daily. eGFR <15 mL/min/1.73 m²: 200 mg once daily.
Liver impairmentChild-Pugh Class A: no adjustment. Child-Pugh Class B: 400 mg per day in divided doses. Child-Pugh Class C: not recommended.
Pediatric useChildren (6–12 years): 10–15 mg/kg per dose twice daily, max 600 mg daily. Adolescents (12–18 years): same as adult dosing.
Geriatric useStart at the lower end of the dosing range (600 mg/day in divided doses) and titrate based on renal function; monitor for side effects.

Use during pregnancy

1st trimesterNo adequate studies in humans; animal studies not available. Use only if potential benefit justifies potential risk to fetus.
2nd trimesterNo adequate studies in humans; animal studies not available. Use only if potential benefit justifies potential risk to fetus.
3rd trimesterNo adequate studies in humans; animal studies not available. Use only if potential benefit justifies potential risk to fetus.

Clinical note

Comprehensive clinical and safety monograph for OZOBAX DS (OZOBAX DS).

Placental transferNo published data available; molecular weight suggests placental transfer expected.
BreastfeedingIt is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when administered to a nursing woman. Discontinue breastfeeding or the drug, taking into account the importance of the drug to the mother.
Lactation RatingL3 (Moderately Safe)
Teratogenic RiskOzobax DS (baclofen) is classified as FDA Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. In animal studies, baclofen has been shown to increase the incidence of omphalocele (ventral hernia) in fetuses of rats given approximately 3 times the maximum human dose. In rabbits, an increased incidence of incomplete ossification of sternal centers was observed. Cases of neonatal withdrawal syndrome have been reported with chronic maternal use during the third trimester, presenting as hypertonia, tremor, and seizures. Therefore, use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Avoid use in the first trimester unless clearly needed.
Fetal MonitoringMonitor maternal blood pressure, respiratory rate, and level of sedation. Assess for signs of muscle weakness or ataxia. In the fetus, monitor fetal heart rate and growth in cases of prolonged use. After delivery, monitor the neonate for signs of baclofen withdrawal (e.g., hypertonia, irritability, seizures) if the mother used the drug chronically during the third trimester.
Fertility EffectsIn animal studies, baclofen did not impair fertility in rats at doses up to 3 times the maximum human dose. Human data are lacking. No specific effects on human fertility have been reported. However, patients with underlying conditions (e.g., multiple sclerosis) may have fertility issues unrelated to the drug.

Warnings & precautions

■ FDA Black Box Warning

Abrupt discontinuation may precipitate withdrawal syndrome, including severe hyperthermia, altered mental status, and muscle rigidity, which can be life-threatening. Taper slowly.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to any component of the formulation

Clinical Precautions

PrecautionsRisk of withdrawal syndrome with abrupt cessation, Dose-dependent sedation and dizziness may impair ability to drive or operate machinery, May exacerbate psychiatric disorders; use with caution in patients with depression or schizophrenia, Renal impairment requires dose adjustment, Respiratory depression risk, especially with concomitant CNS depressants
Food/DietaryNo specific food interactions; however, taking with food may reduce gastrointestinal discomfort.

Clinical Tips & Counseling

Clinical PearlsOZOBAX DS (baclofen) is a GABA-B receptor agonist used for spasticity. Dosage titration is critical to avoid adverse effects. Abrupt discontinuation can cause withdrawal (hallucinations, seizures). Monitor for respiratory depression, especially in elderly or renal impairment. Consider dose adjustment in renal impairment (CrCl <30 mL/min).
Patient AdviceTake exactly as prescribed; do not stop suddenly. · May cause drowsiness or dizziness; avoid driving until you know how it affects you. · Avoid alcohol as it may worsen side effects. · Report any signs of withdrawal: confusion, hallucinations, seizures. · Take with food to reduce stomach upset.

OZOBAX DS Interactions

Loading safety data…

This overview is compiled from peer-reviewed clinical sources and FDA labeling. It's here to support — not replace — clinical judgment. Always verify dosing against your institution's current protocols before prescribing.

On this page

Mechanism of ActionDosing & administrationUse during pregnancyWarnings & precautionsDrug interactions

Compare with

BACLOFENCARISOPRODOLCARISOPRODOL AND ASPIRINCARISOPRODOL COMPOUNDCHLORZOXAZONE

External sources

DailyMed (NIH) PubMed OpenFDA