Medications used with Iontophoresis
Sarapin is the name brand for the original Pitcher Plant distillate. The no-longer-veterinary label was called P-Bloc. Pitcher Plant and Dexamethasone are the two drugs used in specialized iontophoresis protocols. These medications are prescription medications that Matrix does not sell. Contact your veterinarian for the medications.
Pitcher Plant
Pitcher Plant is a regional anesthetic that provides non-sedating pain relief. The brand Sarapin has been on the market since 1931 and has no known side effects. Sarapin (for people) is known for relief of neuromuscular pain as an injectable with immediate effects, and in some cases, the pain relief lasts days or weeks. In horses (and dogs), this beneficial effect seems similar when phoresed for suspensory and check ligament injuries. Pitcher Plant is also very helpful for ringbone and bone spurs when phoresed for pain and to noticeably reduce the enlarged calcified areas.
Sarapin and equivalents are available from compounding pharmacies. At our store, under Books and Media, is the current list of Pitcher Plant sources. Beware of veterinary product sites claiming to have Sarapin or P-Bloc. List was updated 6/2026.
Polarity: Positive – Sarapin
Dexamethasone
Dexamethasone is a corticosteroid and acts as an anti-inflammatory. It is necessary to use the 4mg/ml strength when phoresing (2 mg/ml is too weak).
Polarity: Negative – Dexamethasone
Horse Cocktail (for Iontophoresis)
The “horse cocktail” is a mixture of 4mg/ml Dexamethasone (optional: 40mg/ml Depo Medrol) for the negative polarity and Pitcher Plant for the positive polarity. Saline Solution can be used if necessary to completely fill the drug-delivery pads. To learn more see the chapter on Iontophoresis in “MicroCurrent for Horses and other vital therapies you should know” by Deborah Powell.