What is DMSO Cream?
DMSO (dimethyl sulfoxide) cream is a topical pharmaceutical preparation containing dimethyl sulfoxide—a clear, colorless liquid solvent with unique membrane-penetrating properties that is FDA-approved only for interstitial cystitis but used off-label in dermatology as both a therapeutic agent and a penetration enhancer for other medications. 1, 2
Chemical Properties and Mechanism
DMSO is an organosulfur compound [(CH3)2SO] produced as a by-product of the wood pulp and paper industry, making it inexpensive and widely available. 3, 1
The molecule readily penetrates and diffuses through biological membranes, which explains its dual role as both an active therapeutic agent and a vehicle to deliver other drugs across the stratum corneum. 1, 4
At low concentrations, DMSO exhibits multiple pharmacological properties: anti-inflammatory, analgesic, vasodilator, anti-platelet aggregation, muscle-relaxing, and free radical scavenging effects. 1, 2
FDA-Approved and Guideline-Supported Uses
The only FDA-approved medical indication for DMSO is palliative treatment of interstitial cystitis, though it has additional approval as a preservative for organ transplantation. 1, 2
For chemotherapy extravasation, the European Society for Medical Oncology recommends 99% DMSO as a topical treatment option for anthracyclines, mitomycin C, or platinum salts, with Level III, B evidence. 5, 6
Extravasation Protocol (Guideline-Based)
Apply 99% DMSO at 4 drops per 10 cm² of skin surface over the affected area, covering twice the area of extravasation. 5, 6
Leave to air dry without dressing and repeat every 8 hours for 7 days (1 week). 5, 6
Administer within the first 10 minutes after extravasation for optimal effect—in clinical series of 144 patients, only 1 developed ulceration when DMSO was applied within this timeframe. 5, 6
Critical contraindication: Never combine DMSO with dexrazoxane (the preferred antidote for anthracycline extravasation). 6
Off-Label Dermatologic Applications
DMSO has been used as an adjuvant in photodynamic therapy (PDT), specifically in combination with 23% ALA gel for treating sarcoidosis, achieving histological clearance with no recurrence at 18 months in case reports. 3
Off-label topical applications have shown promise for: basal cell carcinoma, pressure ulcers, scleroderma, herpes simplex, cutaneous fungal infections, and amyloidosis, though evidence consists primarily of small case series. 1, 2
DMSO is used in Europe (but not FDA-approved in the US) in combination with idoxuridine for topical treatment of herpes zoster, leveraging its penetration-enhancing properties. 2, 4
Role as Penetration Enhancer
DMSO is currently used as a pharmaceutical penetration enhancer in diclofenac sodium topical solution (FDA-approved in the US for osteoarthritis signs and symptoms). 4
The molecule facilitates transdermal delivery of both hydrophilic and lipophilic medications, providing localized drug delivery with robust safety data accumulated over three decades. 4
Safety Profile and Adverse Reactions
Most adverse reactions to DMSO are transient, mild, and dose-dependent, with gastrointestinal and skin reactions being the most common. 7
Common side effects include: skin rash, pruritus after dermal application, intravascular hemolysis after intravenous infusion (at high concentrations), and gastrointestinal discomfort after oral administration—most can be avoided by using more dilute solutions. 2, 7
High concentrations (99%) can cause local erythema, which may interfere with proper evaluation of tissue damage in extravasation cases. 5
DMSO has a relatively low level of toxicity overall, and when used in small doses appears safe. 1, 7
Dosing Considerations
For use as a solvent in research/pharmaceutical applications, do not exceed 5 mL/kg or 10% of injected volume. 5
The dose-response relationship is critical—adverse reactions increase with higher concentrations. 7
Critical Clinical Pitfalls
Never use DMSO and dexrazoxane together for anthracycline extravasation—this combination is contraindicated. 6
Neurotoxic interactions with sulindac have been reported—the safety of DMSO in combination with other drugs has not been fully established. 2
DMSO should not be considered a replacement for standard anti-inflammatory agents in arthritis—it provides only palliative pain relief without altering disease progression. 2
Most clinical trials of DMSO lack rigorous experimental design (randomized, placebo-controlled comparisons), making efficacy claims for many conditions unwarranted based on current evidence. 2