Drug delivery is conducted through various methods such as injection, phonophoresis, and iontophoresis. Iontophoresis is defined as the noninvasive delivery of active ions through epidermis using direct current. The direct current has some disadvantages such as skin burning and limited time of application. Interferential current is a kind of alternating currents without limitations of direct current; so the purpose of this study was to investigate and compare the effects of Lidocaine, interferential current and Lidocaine iontophoresis using interferential current.

Pressure, tactile, and pain thresholds were evaluated before and after the application of Lidocaine, interferential current and Lidocaine iontophoresis using interferential current. Pressure threshold was investigated with a Pesula. Pesula is a pen-like scaled mechanical device that measures the skin pressure threshold. Pesula was pressed to the skin and pressure threshold was measured in mm. Pain and tactile thresholds were investigated using an electrical stimulator.The intensity was gradually increased to the extent that the participant reported a tingling sensation. The displayed intensity was considered as the tactile sense threshold. Then, the intensity was increased to the extent to be intolerable for the participant and this intensity was considered as the maximum pain threshold. The thresholds were recorded in milliampere.

Lidocaine iontophoresis using interferential current can increase perception threshold of pain, and pressure sense more significantly in comparison to the application of Lidocaine and interferential current alone.

Inclusion Criteria:

• healthy women with age between 18 and 25 years old

Exclusion Criteria:

• Systemic disorders,
• neuro-muscular diseases such as diabetes and all forms of neuropathies,
• and use of narcoleptic drugs which may contaminate the results.
• Also, none of the participants were on their menstrual cycle.