Aetna considers the use of phonophoresis experimental and investigational for any indications. Phonophoresis has been used to enhance the absorption of analgesics and anti-inflammatory agents. Controlled clinical trials, however, have failed to demonstrate that phonophoresis increases the rate or extent of absorption of these agents.

Phonophoresis, also known as sonophoresis, has been claimed to enhance the percutaneous absorption of certain pharmacological agents such as anti-inflammatory steroids and local anesthetics from intact skin into the underlying subcutaneous structures by ultrasound, therefore improving their effectiveness.  This procedure is commonly used in physical therapy practices.  The procedure generally utilizes an ultrasound apparatus that generates frequencies of 0.7 to 1.1 MHz. The ultrasound intensities employed usually range from 0.0 to 3.0 Watts per cm².  Both continuous-mode as well as pulse-mode applications were utilized, and most treatments lasted from 5 to 8 mins, with the exception of treatments of larger areas (greater than 36 cm²) requiring more than 8 mins. The exact mechanism enabling drugs to be propelled into the subcutaneous structures is still unclear.

Phonophoresis has been suggested by early studies to enhance the absorption of analgesics and anti-inflammatory agents. More recent, better-controlled studies have consistently failed to demonstrate that phonophoresis increases the rate of absorption or the extent of absorption over placebo. Several reviews stated that more research is needed to ascertain optimal techniques and conditions for safe and efficacious utilization of physical modalities including phonophoresis; and there is a need for additional research to establish clinical effectiveness and determine optimal treatment parameters for the physical agents (e.g., phonophoresis) used most frequently to alleviate pain in hand therapy.

In a randomized study (n = 60) comparing the effectiveness of ibuprofen phonophoresis with conventional ultrasound therapy in patients with knee osteoarthritis, Kozanoglu et al (2003) found that ibuprofen phonophoresis was not superior to conventional ultrasound.

Ellis et al (2007) stated that Iliotibial band friction syndrome (ITBFS) is a common injury of the lateral aspect of the knee particularly in runners, cyclists and endurance sports. A number of investigators suggested that ITBFS responds well to conservative treatment, however, much of this notion appears anecdotal and is not supported by available evidence. These researchers performed a systematic review of the literature on the conservative treatment of ITBFS. With respect to the management of ITBFS, 4 randomized controlled trials were identified. The interventions examined included the use of non-steroidal anti-inflammatory drugs, deep friction massage, phonophoresis versus immobilization and corticosteroid injection. This review highlighted both the paucity in quality and quantity of research regarding the conservative treatment of ITBFS. There seems limited evidence to suggest that the conservative treatments that have been studied offer any significant benefit in the management of ITBFS. The authors noted that future research will need to re-examine those conservative therapies, which have already been examined, along with others, and will need to be of sufficient quality to enable accurate clinical judgements to be made regarding their use.

In a review on factors that influence the quality and effectiveness of ultrasound and phonophoresis treatment, Goraj-Szczypiorowska and colleagues (2007) noted that although phonophoresis is commonly used among physical therapists, doubts persist as to the relevance and effectiveness of this method. Despite its popularity, the issue of conditions underlying the effectiveness of phonophoresis treatment has still not been adequately addressed. Particular areas of interest include: (i) treatment parameters to be followed in physical therapy, (ii) appropriate dosage forms of drugs to ensure propagation of ultrasound waves, (iii) principles of homoeostasis and other physiological processes that play a decisive role in achieving the biological and therapeutic effects of ultrasound therapy, and (iv) indications and contraindications to this kind of treatment. The dearth of objective research methods and reliable scientific verification does not allow unambiguous determination of the effectiveness of phonophoresis.