Microneedles—a technique for allowing medications to be absorbed through the skin—have recently been studied to assist in the delivery of the drug naltrexone, a drug used to aid those suffering from alcohol and opioid dependence.
Both currently used methods of administering naltrexone have disadvantages. The oral form of naltrexone only lasts for a short time, leading to “problems with compliance,” according to the National Institute on Drug Abuse (NIDA) (2014). In addition, the oral naltrexone is difficult to dose optimally and can cause liver damage. The other method of naltrexone treatment is an intramuscular shot, which can be painful. It is the hope of researchers that microneedles may provide a painless and more stable method of delivering naltrexone to patients.
According to NIDA, this is how the microneedles work: “The clinician presses a dime-sized array of microneedles briefly into the patient’s skin, opening a grid of micropores. The microneedles are withdrawn, and a medication-impregnated patch is applied over the grid. The micropores diffuse the medication through the epidermis into the microcirculation and bloodstream” (2014).
The only problematic issue with microneedles as a method of administering naltrexone, found as a result of a study done in 2009, was that the micropores closed in a couple of days, requiring frequent retreatment and therefore limiting the pragmatism of the method.
However, the most recent study on microneedles and naltrexone has found that applying a topical gel of diclofenac, an anti-inflammatory medication, before applying microneedles and every couple of days after, kept the micropores open and the medication working for seven days (NIDA, 2014).
Researchers are still investigating the benefits and potential skin-related consequences of diclofenac, and state that more research is needed into this new method of naltrexone treatment.
National Institute on Drug Abuse (NIDA). (2014). Microneedle milestone: One week of transdermal drug delivery. NIDA Notes. Retrieved from http://www.drugabuse.gov/news-events/nida-notes/2014/03/microneedle-milestone-one-week-transdermal-drug-delivery