Baclofen medical use: what it treats, how it works, and what to watch for

Baclofen is a muscle relaxant most doctors use to treat spasticity — the tight, stiff muscles that come with multiple sclerosis, spinal cord injury, or certain brain conditions. It calms the overactive reflexes in your spinal cord so muscles relax. That’s the main medical use, but there are a few off-label roles too. Knowing when it helps and how to use it safely makes a big difference.

What baclofen treats and how it works

Used most often for: moderate to severe spasticity from MS, spinal cord lesions, or cerebral palsy. When oral baclofen isn’t enough, an intrathecal baclofen pump (delivers the drug into the spinal fluid) can control symptoms with much lower doses and fewer systemic side effects.

Mechanism in plain language: baclofen stimulates GABA-B receptors in the spinal cord, turning down the nerve signals that cause muscles to contract. That reduces spasms, improves range of motion, and can make daily tasks easier.

Off-label uses you might hear about: persistent hiccups that don’t respond to other treatments, and for alcohol use disorder. Several small clinical trials showed baclofen helped reduce cravings in some people, but results are mixed and it’s not a first-line alcohol treatment.

Dosing, side effects, and safety tips

Typical starting dose for adults is low—often 5 mg three times a day—and your doctor will slowly raise it. Maintenance doses commonly end up between 30–80 mg per day split into several doses. Higher oral doses raise side-effect risks. Intrathecal dosing is far lower and managed by specialists.

Common side effects: drowsiness, dizziness, weakness, nausea, and lightheadedness. These usually improve after a few days or with dose changes. Practical tip: don’t drive or operate heavy machinery until you know how baclofen affects you.

Major caution: never stop baclofen suddenly. Abrupt withdrawal can cause severe symptoms—hallucinations, high fever, rebound spasticity, and even seizures. If you need to stop, your doctor will taper the dose slowly, sometimes in a monitored setting for high-dose users.

Other safety points: baclofen is cleared by the kidneys, so people with reduced kidney function usually need lower doses. Avoid mixing with alcohol, opioids, or benzodiazepines because combined sedation raises the risk of breathing problems. Tell your clinician about all drugs you take to check interactions.

When to call a doctor: sudden confusion, severe sedation, trouble breathing, new seizures, or signs of withdrawal after a missed dose. If spasticity suddenly worsens or you notice fever and muscle stiffness, seek medical advice quickly.

Baclofen helps many people live with spastic muscles, but it needs careful dosing and respect for safety rules. Ask your prescriber about alternatives like physical therapy, botulinum toxin injections for focal spasticity, or an intrathecal pump if oral treatment isn’t enough.