Is Volterran (diclofenac) gel and menthol patches safe in pregnant women?

Safety of Voltaren (Diclofenac) Gel and Menthol Patches in Pregnancy

Topical diclofenac (Voltaren) gel and menthol patches should be avoided during pregnancy, especially in the third trimester, due to potential risks to the fetus including premature closure of the ductus arteriosus and oligohydramnios.

Diclofenac in Pregnancy

Safety Profile

• Diclofenac belongs to the nonsteroidal anti-inflammatory drug (NSAID) class, which carries specific risks during pregnancy 1
• The FDA drug label for diclofenac specifically warns about fetal risks, particularly in the later stages of pregnancy 1
• While oral diclofenac exposure during the first trimester has not shown increased risk of major birth defects in observational studies, this cannot be extrapolated to safety throughout pregnancy 2

Specific Pregnancy Risks

• NSAIDs including diclofenac should be avoided after gestational week 28 (third trimester) due to risk of premature closure of the fetal ductus arteriosus 3
• Use of NSAIDs at about 20 weeks gestation or later has been associated with fetal renal dysfunction leading to oligohydramnios 1
• The FDA recommends limiting dose and duration of diclofenac use between 20-30 weeks gestation and avoiding it completely after 30 weeks 1

Topical Formulations and Absorption

Transdermal Absorption

• While topical formulations have limited systemic absorption compared to oral medications, some absorption still occurs 4
• The addition of menthol to diclofenac formulations can enhance skin permeation and increase systemic absorption 5
• Combination products containing diclofenac and menthol have shown higher irritation potential in patch studies, which may further increase absorption 6

Considerations for Topical Use

• Even with limited systemic absorption, the FDA pregnancy warnings for diclofenac apply to all formulations 1
• There are insufficient safety data specifically evaluating topical diclofenac in pregnancy 7
• The risk-benefit ratio must be carefully considered, especially given the availability of safer alternatives 3

Alternative Pain Management Options in Pregnancy

Safer Alternatives

• Acetaminophen is generally considered safe during pregnancy and is the preferred analgesic for pregnant women 7
• For topical pain relief, some products containing lidocaine may be safer options, though data is limited 4
• Non-pharmacological approaches such as physical therapy, heat therapy (without menthol), or massage should be considered first-line 3

Clinical Recommendations

First and Second Trimester

• If pain management is necessary, acetaminophen should be considered as first-line therapy 7
• If topical therapy is required, use should be limited to the smallest effective area for the shortest duration possible 1
• Monitor for potential adverse effects if topical diclofenac is used before 20 weeks gestation 1

Third Trimester

• Avoid all NSAID products including topical diclofenac after 28 weeks gestation due to increased risk of premature closure of the fetal ductus arteriosus 3, 1
• If treatment with diclofenac is needed between 20-30 weeks, ultrasound monitoring for oligohydramnios should be considered if treatment extends beyond 48 hours 1
• Discontinue immediately if oligohydramnios is detected 1

Conclusion

The risks of using topical diclofenac with menthol during pregnancy outweigh the potential benefits when safer alternatives exist. The combination of diclofenac and menthol may increase absorption and potential fetal exposure. Acetaminophen remains the safest analgesic option during pregnancy, and non-pharmacological approaches should be considered when appropriate.