Is baclofen (GABA receptor agonist) effective for treating neck strain?

Baclofen is Not Recommended for Neck Strain

Baclofen should not be used for neck strain, as it is a GABA-B agonist indicated specifically for spasticity from upper motor neuron lesions, not for acute musculoskeletal pain conditions like neck strain. 1

Evidence Against Baclofen for Neck Strain

Limited and Weak Evidence for Musculoskeletal Pain

• There is only sparse data (2 trials) supporting baclofen's efficacy for low back pain, and even less evidence for neck strain specifically 1
• While one older study from 1985 showed baclofen (30-80 mg daily) was effective for acute low-back syndrome in patients with initially severe symptoms, this represents minimal evidence and does not extend to neck strain 2
• A systematic review found insufficient or very limited evidence regarding the effectiveness of baclofen compared to placebo in patients with musculoskeletal conditions 3

Baclofen's Primary Indication is Spasticity, Not Pain

• Baclofen is primarily a GABA-B agonist used for spasticity from upper motor neuron lesions (spinal cord injury, multiple sclerosis, stroke), not for pain management 1
• The American Geriatrics Society explicitly states there is minimal data supporting the use of baclofen for pain outside of spasticity-related conditions 1

Significant Safety Concerns

Common Adverse Effects

• Baclofen causes significant adverse effects including dizziness, sedation, excessive weakness, vertigo, and gastrointestinal symptoms 1, 4
• The incidence of adverse effects ranges from 10% to 75%, with most being dose-related 4
• Baclofen may worsen obstructive sleep apnea by promoting upper airway collapse during sleep 1

Serious Withdrawal Risk

• Abrupt discontinuation of baclofen can lead to life-threatening withdrawal symptoms including seizures, hallucinations, delirium, anxiety, agitation, fever, tremors, tachycardia, hyperthermia, and potentially death 1, 5, 4
• These withdrawal symptoms improve after reintroduction of baclofen, but the risk makes casual use for musculoskeletal pain inappropriate 4

Recommended Alternatives for Neck Strain

First-Line Pharmacological Options

• Cyclobenzaprine has been evaluated in the most clinical trials for acute musculoskeletal conditions (including neck pain) and has consistently been found effective 3
• Other muscle relaxants with fair evidence for musculoskeletal conditions include carisoprodol, orphenadrine, and tizanidine 3

For Neuropathic Components (if present)

• Consider gabapentinoids (pregabalin, gabapentin) which have stronger evidence for neuropathic pain and are recommended as first-line adjuvant analgesics by the American Geriatrics Society 1
• Analgesic antidepressants, particularly duloxetine and tricyclic antidepressants (TCAs), may be appropriate for certain pain presentations 1

Non-Pharmacological Approaches

• Physical therapy modalities, range of motion exercises, and stretching should be considered as first-line interventions 1
• Appropriate positioning and functional exercises are recommended before pharmacological intervention 1

Clinical Pitfall to Avoid

Do not confuse muscle spasm from acute musculoskeletal injury (neck strain) with spasticity from upper motor neuron lesions. Baclofen is designed for the latter condition, where there is pathological velocity-dependent increase in muscle tone with exaggerated reflexes. Neck strain involves muscle spasm from local tissue injury, which responds better to traditional muscle relaxants like cyclobenzaprine 1, 3.