Treatments for most forms of arthritis are aimed at relieving symptoms. The prototypical agents used to treat arthritis are the non-steroidal anti-inflammatory drugs. These are generally oral medicines which can work well for most people. However, they do have potential side-effects that limit their utility.

Recently, there has been more emphasis place on using topical treatments that may have less potential for side effects.

Topical agents used in arthritis - sometimes off label- meaning they are not FDA approved for the indication but are used for it anyway- are divided into three subclasses:

* Non-steroidal anti-inflammatory drugs
* Topical anesthetics
* Counterirritants

Non-steroidal anti-inflammatory drugs:

Topical anti-inflammatory drugs generally are safer than oral anti-inflammatory drugs. However, they still have the potential for side-effects including an increased incidence of gastrointestinal bleeding as well as cardiovascular events. And like oral NSAIDS, topicals are contraindicated for treatment of pain in the immediate postoperative period following coronary bypass surgery.

There are three topical treatments available. The first is called the Flector patch. It is approved by the FDA for treatment of minor strain and related pain disorder. It is a transdermal patch containing diclofenac, a non-steroidal anti-inflammatory drug that is worn for 12 hours at a time.

Another topical preparation is Pennsaid, which is a liquid form of diclofenac that is combined with DMSO for more rapid absorption through the skin. It's indicated for osteoarthritis of the knee and is applied three to four times a day.

The other topical preparation is Voltaren gel, another diclofenac-based agent. It is an ointment that comes in a tube and is indicated for osteoarthritis of the knee and hands. It can be applied four times a day.

All three diclofenac preparations have been shown to be superior to placebo in the treatment of the disorders for which they are indicated.

All three have the same contraindications and potential side effects including too much systemic absorption of diclofenac, redness and itching due to skin irritation, blisters, and allergic reactions.

Topical anesthetics:

Topical anesthetics come in a number of forms. There is a transdermal patch containing lidocaine (Lidoderm). It should be used only on intact skin and extreme caution should be exercised in using this preparation in patients who are taking class 1 anti-arrhythmic drugs for their hearts since systemic absorption can lead to drug interaction. Lidoderm's use for arthritis is considered off-label use. Potential side effects are rash, skin irritation, but can also include reactions from systemic lidocaine exposure including light-headedness, confusion, and even death.

Obviously, patients who are allergic to lidocaine shouldn't get this patch.

Another patch, (Synera) also contains lidocaine and tetracaine. Many of the same precautions should be used for this patch as with the Lidoderm patch and use of this patch for arthritis is considered off-label.

A lidocaine/prilocaine cream (EMLA) has also been employed on occasion for anesthetizing the skin before procedures such as venipuncture, etc. It really doesn't work that well for aches and pains and its use for arthritis should be considered an off-label use.

Counterirritants:

Counterirritants are drugs that work by desensitizing nociceptive (pain perceiving) nerve endings in the skin. These agents are used for muscle aches, strains, strains, and arthritis.

Capsaicin containing compounds are the most commonly used. They can cause undesirable side effects such as skin irritation, lung irritation, and hypertension.

Other counterirritant preparations include ingredients such as camphor (Tiger Balm), salicylates (Aspercreme), menthol (Icy Hot), and methylsalicylate (BenGay). Compounds containing salicylates have the potential to cause drug interaction in patients taking anticoagulant drugs such as warfarin.

Counterirritants should be used short term only.

Another precaution regarding patches: dispose of them properly and keep them out of the reach of children and pets.

Discussion of narcotic patches is beyond the scope of this article.