Summary

Drugs are a key element in the treatment of pain. According to Pain Therapeutics, Inc., a pain drugs manufacturer, the United States and Western Europe market for pain drugs totals more than $12 billion. The pain management market has grown significantly in recent years and analysts expect it to continue to grow significantly. This accelerating growth rate appears to be attributable in part to recent innovations in the treatment of pain.  There has been little innovation in the area of opioid painkillers. Sales of opioid painkillers in the United States are primarily of older off-patent pain drugs, such as morphine and oxycodone.

NSAIDs are most effective for mild to moderate pain accompanied by swelling and inflammation. These drugs relieve pain by inhibiting an enzyme in your body called cyclooxygenase. This enzyme makes hormone-like substances called prostaglandins, which are involved in the development of pain and inflammation. NSAIDs are especially helpful for arthritis and pain resulting from muscle sprains, strains, back and neck injuries or cramps.

When taken as directed, NSAIDs are generally safe. But if more than the recommended dosage is taken — and sometimes even the recommended dosage — NSAIDs may cause nausea, stomach pain, stomach bleeding or ulcers. Large doses of NSAIDs can lead to kidney problems and fluid retention. Risk increases with age. If you regularly take NSAIDs, talk to your doctor so that he or she can monitor you for side effects.

NSAIDs have a so-called ceiling effect, or limit to how much pain they can control. This means that beyond a certain dosage, they don't provide additional benefit. If someone has moderate to severe pain, exceeding the dosage limit may not help relieve the pain.

Many NSAIDs require a prescription, but some lower-dose NSAIDs, such as aspirin and ibuprofen, are available over-the-counter. These nonprescription NSAIDs are generally divided into two groups.

Over-the-counter NSAIDs include: (click links for details on each)

• Aspirin

• Ibuprofen (Advil, Motrin, others)

• Ketoprofen (Orudis)

• Naproxen sodium (Aleve)

NSAIDs available only by prescription include:

Opioids are prescription medications and are regulated as controlled substances by the Drug Enforcement Administration. A doctor must have a special license in order to prescribe these drugs.

Opioids are often used to relieve pain from cancer, terminal illness, severe injury or surgery. They come in several forms. Some are natural compounds derived from the opium poppy. These are called opiates. There are also synthetic opioids that work in similar ways. Opioids include both these natural and synthetic forms and is the preferred term.

Frequently prescribed opioids include the following: (click links for details on each)

COX-2 inhibitors are a type of nonsteroidal anti-inflammatory drug (NSAID) that specifically inhibits an enzyme known as cyclooxygenase-2 (COX-2). These drugs are used to treat pain and may be less likely to cause gastrointestinal bleeding than other NSAIDs.

Cyclooxygenase comes in two forms: COX-1 and COX-2. Unlike other NSAIDs, COX-2 inhibitors suppress only one form of cyclooxygenase, COX-2.

Researchers believe part of the role of COX-1 is to protect your stomach lining. Because the other NSAIDs suppress its function, side effects such as stomach and bleeding problems can result. COX-2 inhibitors affect only that form of the enzyme (COX-2) involved in inflammation. Because they don't affect COX-1, COX-2 inhibitors may cause fewer side effects in your digestive system. However, this result, along with the long-term effects of COX-2 inhibitors, needs to be verified with further research.

In addition, COX-2 inhibitors don't thin your blood like aspirin and other NSAIDs. If your doctor has prescribed aspirin for a heart condition, don't use COX-2 inhibitors instead.

COX-2 inhibitors include: (click links for details on each)

• Celecoxib (Celebrex)

• Rofecoxib (Vioxx)

• Valdecoxib (Bextra)

Some of the more effective and commonly used medications for chronic pain are drugs that were developed to control other conditions. Anti-seizure (anticonvulsant) medications were developed primarily to reduce or control epileptic seizures, but they also help control stabbing or shooting pain from nerve damage. These drugs seem to work by quieting damaged nerves to slow or prevent uncontrolled pain signals.

These medications can cause dizziness, drowsiness, nausea and lack of balance and coordination. But most people are bothered only minimally. More severe but less common side effects include blood and liver disorders. To reduce your risk of side effects, your doctor will likely start you off on a small amount of the drug and gradually increase the dose while monitoring you.

Anti-seizure medications used for chronic pain (click links for details on each)

• Carbamazepine (Carbatrol, Tegretol)

• Divalproex sodium (Depakote)

• Gabapentin (Neurontin)

• Lamotrigine (Lamictal)

• Phenytoin (Dilantin)

• Oxcarbazepine (Trileptal)

• Topiramate (Topamax)

• Valproic acid (Depakene)