What are the safest muscle relaxants in pregnancy?

From the Guidelines

During pregnancy, the safest approach to managing muscle spasms is through non-pharmacological methods, and when medication is necessary, cyclobenzaprine (Flexeril) is sometimes prescribed with caution, particularly in the second and third trimesters, at the lowest effective dose for the shortest duration possible, as evidenced by studies such as 1 and 1.

Key Considerations

• Non-pharmacological approaches like physical therapy, massage, heat therapy, and gentle stretching exercises are preferred for managing muscle spasms during pregnancy.
• If medication is necessary, acetaminophen (Tylenol) is considered the safest pain reliever for short-term use.
• Cyclobenzaprine (Flexeril) may be considered for muscle spasms requiring medication, but its use should be cautious and under close medical supervision, especially in the first trimester, due to limited human studies and potential risks, as noted in 1.

Medication Safety

• Benzodiazepines like diazepam (Valium) are generally avoided during pregnancy, especially in the first trimester, due to potential risks of birth defects and neonatal withdrawal.
• Baclofen and methocarbamol may be considered in specific situations where benefits outweigh risks, but only under close medical supervision.

Evidence Base

• The evidence for the safety and efficacy of muscle relaxants during pregnancy is limited, with most studies focusing on their use in the general population, as seen in the systematic reviews included in 1, 1, and 1.
• The American Pain Society and American College of Physicians clinical practice guideline reviews the evidence for medications, including muscle relaxants, for acute and chronic low back pain, highlighting the need for cautious use, as discussed in 1 and 1.

From the Research

Safest Muscle Relaxants in Pregnancy

There are no specific studies that directly compare the safety of different muscle relaxants in pregnancy. However, some studies provide information on the use of muscle relaxants and non-pharmacological interventions in pregnant women.

• The study by 2 highlights the importance of exercising caution when using muscle relaxants during anesthesia in pregnant or postpartum patients, due to pharmacodynamic and pharmacokinetic differences in their action during this period.
• The study by 3 discusses the comparative efficacy of skeletal muscle relaxants, but does not specifically address their use in pregnancy.
• Studies by 4 and 5 investigate the effectiveness of progressive muscle relaxation techniques in reducing anxiety and improving general health in pregnant women, suggesting that non-pharmacological interventions may be a useful alternative to muscle relaxants.
• The study by 6 compares the impact of various non-pharmacological interventions on depressive and anxiety symptoms in pregnant women, finding that mindfulness therapy, cognitive behavioral therapy, and education therapy are effective in improving depressive symptoms, while mindfulness therapy, mind-body exercises, and cognitive-behavioral therapy may also alleviate anxiety symptoms.

Non-Pharmacological Interventions

Non-pharmacological interventions, such as progressive muscle relaxation and mindfulness therapy, may be a safer alternative to muscle relaxants in pregnancy. These interventions have been shown to be effective in reducing anxiety and improving general health in pregnant women, and may be considered as a first-line treatment option.

• Progressive muscle relaxation has been found to be effective in reducing anxiety in pregnant women 4, 5.
• Mindfulness therapy has been found to be effective in improving depressive and anxiety symptoms in pregnant women 6.
• Other non-pharmacological interventions, such as cognitive behavioral therapy and education therapy, may also be effective in improving depressive symptoms in pregnant women 6.