Is it safe to use a lidocaine (local anesthetic) patch during pregnancy?

Safety of Lidocaine Patches During Pregnancy

Lidocaine patches should be used with caution during pregnancy and only when the potential benefits outweigh the risks, as there is limited evidence regarding their safety in pregnant women.

Evidence on Lidocaine Use in Pregnancy

The safety profile of lidocaine patches during pregnancy is not well established in current guidelines. While lidocaine is commonly used in various forms during pregnancy, specific guidance on topical patches is limited.

Transplacental Transfer and Fetal Effects

• Lidocaine crosses the placenta when administered systemically 1
• Research shows that pregnancy increases median nerve susceptibility to lidocaine, suggesting pregnant women may be more sensitive to its effects 1
• Animal studies have demonstrated that lidocaine can adversely affect asphyxiated preterm fetal lambs, causing deterioration in cardiovascular adaptation 2

Systemic Absorption Considerations

• Lidocaine patches (5%) have minimal systemic absorption with mean maximum plasma concentrations well below toxic levels 3
• Pharmacokinetic studies demonstrate that even with extended application (12-24 hours/day), systemic absorption remains low 3
• This limited systemic absorption suggests a reduced risk of fetal exposure compared to injectable or intravenous forms

Clinical Applications During Pregnancy

When Lidocaine Patches May Be Considered

• For localized pain management when other non-pharmacological approaches have failed
• When the benefit of pain control outweighs potential risks
• For short-term use rather than prolonged therapy

FDA Labeling and Warnings

The FDA labeling for lidocaine patches includes important warnings 4:

• For external use only
• Do not use on cut, irritated, or swollen skin
• Do not use for more than one week without consulting a doctor
• Avoid bandaging or applying heat to the area
• Pregnant or breastfeeding women should consult a healthcare professional before use

Recommendations for Clinical Practice

1. Consider alternative non-pharmacological pain management strategies first

   • Physical therapy
   • Position changes
   • Support devices

2. If lidocaine patch is deemed necessary:

   • Use the lowest effective dose
   • Limit application to the smallest area necessary
   • Apply for the shortest duration needed
   • Monitor for adverse effects
   • Do not exceed recommended number of patches (typically 3-4 patches) 5
   • Apply only to intact skin 5
   • Limit wearing time to 12 hours within a 24-hour period 5

3. Avoid use in high-risk situations:

   • First trimester when possible
   • In women with pregnancy complications
   • In combination with other local anesthetics that could increase systemic exposure

Monitoring and Safety Precautions

• Watch for signs of systemic toxicity: circumoral numbness, facial tingling, light-headedness, tinnitus 5
• Discontinue use if skin irritation or signs of skin injury develop 4
• For procedures requiring anesthesia during pregnancy, the Society for Maternal-Fetal Medicine acknowledges the use of lidocaine for local anesthesia during certain procedures 6

While lidocaine patches offer a targeted peripheral analgesic option with minimal systemic absorption, the risk-benefit assessment should be carefully considered for each pregnant patient, with preference given to established pain management approaches with more robust safety data in pregnancy.