What precautions should be taken when prescribing Dimethyl Sulfoxide (DMSO) for 5-Fluorouracil (5-FU) extravasation?

Precautions When Prescribing DMSO for 5-FU Extravasation

Before prescribing dimethyl sulfoxide (DMSO) for 5-fluorouracil (5-FU) extravasation, clinicians must be aware of its contraindications in pregnant patients, potential ocular toxicity, drug interaction risks, and proper application technique to ensure safety and efficacy.

Key Contraindications and Precautions

Absolute Contraindications

• Pregnancy: DMSO should not be used in pregnant patients as studies have shown it to be teratogenic and embryotoxic 1
• Concurrent use with dexrazoxane: The combination of DMSO and dexrazoxane is contraindicated based on animal studies 2
• Application before dexrazoxane administration: Topical cooling and DMSO should be removed 15 minutes before dexrazoxane administration 3

Drug Interactions

• DMSO may facilitate systemic absorption of other topically applied drugs 1
• May potentiate effects of drugs affecting cardiovascular and central nervous systems 1
• Other medications should not be present at the site of DMSO application 1
• If other topical medications are needed, they should only be applied after DMSO has thoroughly dried 1

Application Technique

• Apply DMSO 99% at four drops per 10 cm² of skin surface 3, 4
• Cover twice the affected area 3
• Apply every 8 hours for 7 days 3, 4
• Allow to air dry without dressing 3
• Ideally, administer within 10 minutes after extravasation for best results 3

Monitoring and Side Effects

Potential Side Effects

• Local erythema that may affect accurate evaluation of tissue damage 3
• Local burning sensation 5
• Characteristic breath odor 5
• Potential ocular toxicity with prolonged use (based on animal studies) 1
  • Changes in refractive index of the lens
  • Nuclear cataracts (observed in animals with high doses/long duration)

Required Monitoring

• Document the extravasation area with photographs if possible 4
• Schedule follow-up within 7 days for reassessment 4
• Continue monitoring for 3-4 weeks 4
• Evaluate for signs of tissue necrosis or progressive damage 4

Practical Administration Guidelines

Concurrent Treatments

• Apply dry cold compresses for 20 minutes several times daily for 1-2 days 3, 4
• Avoid alcohol compresses as they may worsen the injury 4
• Elevate the affected limb to reduce swelling 4
• Administer analgesia as needed for pain management 4

Material Considerations

• DMSO is a potent solvent that may damage fabrics, plastics, and other materials 1
• Avoid physical contact with DMSO during application 1
• Contact with the treated area should be avoided until drying has occurred 1

Documentation Requirements

• Patient information
• Date and time of extravasation
• Name of drug extravasated and diluent used
• Signs and symptoms reported by patient
• Description of the IV access used
• Estimated extravasation area and amount
• Management steps with time and date 4

Alternative Considerations

• In some countries, only DMSO at a concentration of 50% may be available (versus the recommended 99%) 3
• For anthracycline extravasations, dexrazoxane may be preferred as first-line treatment 4, 6
• Semisolid formulations containing DMSO and alpha-tocopherol may provide extended contact time and reduced irritation compared to solutions 7

By following these precautions and guidelines, clinicians can optimize the safety and effectiveness of DMSO in managing 5-FU extravasation.