Can lorazepam (Ativan) cause muscle spasms and is klonopin (clonazepam) a safe alternative?

Lorazepam and Muscle Spasms: Clinical Guidance

Lorazepam does not cause muscle spasms; rather, benzodiazepines including both lorazepam and clonazepam (Klonopin) are actually used to treat muscle spasm, though neither is a first-line choice and both carry significant risks, particularly in older adults. 1

Understanding Benzodiazepines and Muscle Effects

Mechanism of Action

• Benzodiazepines activate GABA-A receptors in the brain and have known effects on muscle spasm relief, not muscle spasm induction 1
• Both lorazepam and clonazepam possess muscle relaxant properties through their benzodiazepine receptor activity 1, 2
• These agents may be justified for relief of muscle spasm, especially when anxiety, muscle spasm, and pain coexist 1

Clinical Evidence for Muscle Relaxation

• If muscle spasm is suspected as the root cause of pain, benzodiazepines (including both lorazepam and clonazepam) are considered appropriate alternatives to traditional muscle relaxants 1
• Clonazepam specifically has demonstrated effectiveness for pain due to muscle spasm in case reports, with both muscle relaxant and anxiolytic effects 3
• Diazepam (another benzodiazepine) has been shown to directly reduce muscle contraction amplitude and isometric twitch tension in patients with spasticity 4

Comparing Lorazepam vs. Clonazepam

Pharmacological Differences

• Lorazepam has a shorter elimination half-life (8-15 hours) and no active metabolites 1
• Clonazepam has a longer duration of action, which may provide more sustained muscle relaxation 1
• Both agents carry similar mechanisms for muscle relaxation through benzodiazepine/GABA receptor systems 2

Safety Profile: Neither is "Safer"

Switching from lorazepam to clonazepam does not improve safety—both carry identical high-risk profiles, particularly for older adults. 1

• Both agents cause respiratory depression, hypotension, sedation, cognitive impairment, and increased fall risk 1
• Both are associated with delirium risk, especially in older patients 1
• Both cause tolerance, dependence, and withdrawal syndromes with prolonged use 1
• The high risk profile in older adults usually obviates any potential benefit for pain or muscle spasm relief 1

Specific Risks Common to Both Agents

• Central nervous system depression: drowsiness, dizziness, fatigue, lightheadedness 1, 5
• Increased fall risk and motor skill impairment 1
• Cognitive impairment and slowed comprehension 1
• Paradoxical agitation and anxiety in some patients 1
• Risk of propylene glycol toxicity with lorazepam formulations (metabolic acidosis, acute kidney injury) 1

Clinical Recommendations

When Benzodiazepines May Be Considered for Muscle Spasm

• Only when muscle spasm is clearly identified as the pain source 1
• When anxiety, muscle spasm, and pain coexist 1
• For short-term use only (days, not weeks) 5
• At the lowest effective dose 1

Preferred Alternatives to Both Agents

If muscle spasm treatment is needed, consider baclofen as a first-line alternative rather than switching between benzodiazepines. 1

• Baclofen is specifically recommended for severe spasticity and muscle spasm due to CNS injury or neuromuscular disorders 1
• Baclofen has documented efficacy for muscle spasm without the same abuse potential as benzodiazepines 1
• Start baclofen at low doses and gradually increase to minimize dizziness, somnolence, and GI symptoms 1

Critical Pitfalls to Avoid

• Do not prescribe traditional "muscle relaxants" (cyclobenzaprine, methocarbamol, carisoprodol) believing they relieve muscle spasm—their effects are nonspecific and not related to actual muscle relaxation 1
• Avoid long-term benzodiazepine use (>2 weeks) due to accumulating adverse effects, particularly drowsiness and dizziness (NNTH 3) 5
• Be aware that even short-term benzodiazepine use (24 hours to 2 weeks) is associated with significant adverse events 5
• Never assume one benzodiazepine is "safer" than another for muscle spasm—the class effects are consistent 1

Deprescribing Considerations

• Both lorazepam and clonazepam should be tapered slowly if discontinuing after prolonged use 1
• Consider cognitive behavioral therapy and non-pharmacological interventions as alternatives 1
• Physical therapy and exercise may be more effective for musculoskeletal pain than benzodiazepines 1