pain management
pain management

Transdermal Solutions for Pain Management

Whether you are suffering from acute pain associated with injury or chronic pain associated with arthritis, compounded medications can be made to meet specific patient’s needs. There are many options that a compounded medication can offer to aid in possibly treating and relieving pain. Topical pain gels are applied directly to the affected area to block pain at the nerve source. Pain gels are compounded with a deep penetrating base, which has been proven effective in facilitating absorbing topical pain medications through the skin.

Successful treatment of acute and chronic pain has been and continues to be a challenge for physicians and pharmacists alike. Traditional oral drug therapies, although effective, can have detrimental side effects that prohibit their use. Compounded pain gels offer practitioners a viable treatment option and alternative dosage form with decreased systemic side effects. In disease states and injuries where pain is present, successful pain management is a major key in achieving therapeutic success and improving quality of life. Many traditional drug regimens such as opioid analgesics and oral nonsteroidal anti-inflammatory drugs (NSAIDs) are beginning to lose popularity due to undesirable adverse effects. Many forms of pain are due, at least in part, to inflammation, which is often localized to one part of the body or site of injury. In cases such as these, transdermal pain gels may provide a viable option for physicians looking to find an effective route of administration while minimizing the detrimental systemic effects of these drugs.

Pain Classifications
Before choosing a drug therapy, one needs to understand the basics of pain. The International Association for the Study of Pain defines it as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.” Pain can be classified as “acute” or “chronic.” Acute pain typically results from disease, inflammation or tissue injury and generally comes on suddenly. Chronic pain, on the other hand, tends to persist over a longer period of time and is more likely resembles the disease itself. Prostaglandin release and subsequent stimulation of pain receptors during stress, trauma or inflammation is one of two major mechanisms to produce pain. The other mechanism involves release of substance P, which can prolong the duration of pain by extending the excitation of pain receptors. When choosing a drug therapy, it is important to use a medication that directly affects these pain mechanisms.

Active Ingredients in Transdermal Pain Gels
NSAIDs
Ketoprofen and others like it work to decrease pain and inflammation by inhibiting the formation of leukotrienes and prostaglandins. Although NSAIDs can cause serious gastrointestinal (GI) side effects when taken orally, recent studies have shown that transdermal formulas have several advantages over their oral counterparts. These advantages include rapid onset of action, avoiding GI-tract irritation and first-pass metabolism, increased elimination half-life, prolonged therapeutic effect, control over the areas of absorption, few if any systemic side effects, and improved patient compliance.

Baclofen
It’s a muscle relaxant/antispasmodic that helps reduce pain by relaxing muscles. Since topical use causes much less systemic absorption, the typical side effects (drowsiness, increased urination, mental confusion, constipation and fatigue) are usually absent.

Cyclobenzaprine
It’s a muscle relaxant that helps control muscle spasms and tightness. A common side effect when taken orally is drowsiness, but transdermal medication reduces this risk.

Gabapentin
It works by three mechanisms which may help with neuropathic pain (pain typically caused by damaged or misfiring nerve fibers).

Ketamine
It’s an analgesic (an agent used to relieve pain without loss of sensation) that helps reduce pain by interfering with pain signals being transmitted to the brain. Extensive research has been performed on its topical use.

Lidocaine
It’s a topical anesthetic that helps reduce pain. The most common transdermal side effects are tingling and numbness at the site of application.

Tramadol
It’s a mild opioid-like pain reliever.

Transdermal Application Challenges
The main challenge for transdermal application is penetrating the skin layers. The topmost skin layer, the epidermis, provides the strongest protection against drug absorption and is composed of five different sublayers: stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale. The stratum corneum can be compared structurally to a brick wall, and getting drugs to penetrate it has proven difficult for most creams and ointments in the past, but the recent development of oil/water microemulsion systems by compounding pharmacies have provided transdermal vehicles that are balanced for delivery of hydrophilic and hydrophobic drugs.

Pluronic Lecithin Organogel (PLO)
The gold standard of transdermal delivery systems is pluronic lecithin organogel (PLO), which is composed of pluronic gel (the water phase) and lecithin/isopropyl palmitate (the oil phase). This microemulsion has been shown to have the ability to deliver NSAIDs across the epidermal barrier through either simple diffusion through the lipid intercellular matrix or by the skin’ slight disorganization, which allows the drug to pass through the stratum corneum. The research and development of transdermal pain gels has led to extensive use among various physician groups ranging from general practice to orthopedic specialists. Several case studies have shown transdermal gels are effective for treating pain relating to sever disease, delayed onset muscle soreness, rheumatic disease, orofacial neuropathic pain and various soft-tissue conditions.

Lipoderm
Lipoderm is a liposome-containing base used to increase the permeation of various active ingredients. It is often used in place of PLO gels for transdermal-compounded preparations. Its physical characteristics include smoothness and creaminess. It is a stable system that does not separate when refrigerated, and it tolerates ionic substances well. Successful treatment of acute and chronic pain has been and continues to be a challenge for physicians and pharmacists alike. Traditional oral drug therapies, although effective, can have detrimental side effects that prohibit their use. Compounded transdermal gels offer practitioners a viable treatment option and alternative dosage form for pain therapy with decreased systemic side effects.