Medications can cure many illnesses and often relieve complaints. They will not fix everything (in spite of what the manufacturer’s may say). Every medication, even aspirin, has significant risk. Use your medicines with caution and follow all instructions. Do not share medications with friends or relatives.
We will review the most common risks when we prescribe a medication. The label will have a few warnings. The less common risks are listed on the manufacturer’s web page (the pages for the medications we use most are listed at the end of this page). There may be other risks which have not yet been discovered. This is especially true with newer medications (remember Celebrex, Vioxx, and Bextra).
Agonists and Antagonists
Medications typically work by either stimulating a receptor site or blocking the same site so that other chemicals cannot stimulate it.
Drugs that stimulate are called agonists and those that block are called antagonists. Narcotics are classic agonist drugs. These pain medications go to specific receptors in the body and cause the receptors to shut down the pain response. Non-steroidal medications (including aspirin) are classic antagonist drugs. Cyclo-oxygenase is an enzyme which is blocked by the anti-inflammatory medicines. Blocking this enzyme (antagonist) reduces inflammation and therefore decreases pain.
About half of the drugs we use are agonists and the other half are antagonists. The strength of the drug is determined by how well they bind the receptor sites or how well they block those sites.
How are medications delivered?
Medications may be delivered in a variety of ways. The easiest is by pill. Pills are easily swallowed and most can start working in a few minutes. Some medications, however, are destroyed by stomach acids and therefore do not work as pills. To make a pill "long acting," one can change the chemicals that are with the medicine to slow its absorption or one can put the pill in a hard shell that dissolves only slowly. To make a medicine quick acting, one can make it chewable so that it begins to be absorbed in the mouth.
Some medications have to be given as shots into the space under the skin (subcutaneous space) or into the muscles or as intravenous injections into the blood directly. These include medications that have to be given very quickly (such as in an emergency or during anesthesia) or those that would be destroyed by the stomach (like insulin).
A few medications can be given directly through the skin. These are called transdermal. Transdermal medications have the advantage of being absorbed very slowly and lasting a long time. These include some long acting narcotics, such as fentanyl, that are good for chronic pain. They also include some which cannot go through the stomach, such as scopolamine, a drug used for motion sickness.
A few words about aspirin and other non-steroidals.
Plant-derived salicylates have been used traditionally by many cultures for the treatment of pain and fever. In a 1763 publication, Edmund Stone described the use of salicin-containing willow bark to treat fever in a series of patients in England. The synthesis of acetylsalicylic acid (by Bayer) in the 1890s ushered in the era of pain management with aspirin. This became the most frequently used drug in the world.
Many nonsteroidal anti-inflammatory drugs (NSAIDs) have been developed since aspirin was discovered: over 50 NSAIDs and over 200 aspirin-containing compounds are currently available in the United States. More than 13 million people use an NSAID daily.
Despite widespread clinical use of NSAIDs for nearly a century, their mechanism of action was not understood until 1971, when it was proposed that these agents inhibit prostaglandin synthesis.(4) Cyclooxygenases are critical enzymes in the biosynthetic pathways of many bioactive compounds originating from arachidonic acid, including prostaglandins, thromboxanes, and prostacyclins. Together with the lipoxygenases, cyclooxygenase (COX) enzymes play a key role in inflammation, pain, and other biologic processes. Specifically targeting these enzymes has been a major goal of drug design for the past 2 decades.
Information on Cyclooxygenase-2-Selective (COX-2) Inhibitors (Vioxx, Celebrex, Bextra and Mobic)
Anti-inflammatory agents treat pain but can cause stomach upset and ulcers. The discovery of cyclooxygenase-2(COX-2) was initially hailed as a major advance. The COX-2 drugs were thought to have the benefits of older NSAIDs with reduced chance of ulcers.
Unfortunately, these drugs did not work as well as the older non-steroidals, are extremely expensive, and recent studies have shown that COX-2 inhibitors may cause stroke or heart attack. Vioxx has been removed from the market and Celebrex may soon follow. Bextra and Mobic, both similar drugs are also suspect. As of the writing of this entry in December of 2004, unless there are very specific reasons why one cannot use a Motrin-like medication, the use of COX-2 inhibitors would probably be unwise. In other words, if you have Vioxx, Celebrex, Bextra or Mobic, you should stop using them and throw out any remaining pills. You should see your doctor for a replacement.
A few words on Opiates.
Opiates are pain medications that resemble opium. Opium has been used for thousands of years to control pain. It is found in Asian poppy plants. Most patients use opium to control pain. Opiates include Vicodin, Percocet, Darvocet, hydrocodone, Demerol, methadone, heroin, morphine, fentanyl oxycodone, Dilaudid and many others.
Opiates work as agonists by binding into receptor sites on cells in the brain and spinal cord. The human brain actually makes its own chemicals that bind these receptors. These chemicals are called endorphins and enkephalins. Opiates bind to the same receptor sites and change the way your brain and spinal cord process pain signals. Your pain is then reduced.
There are many side effects to opiates. The most common two are sedation and constipation. There are many other side effects including nausea, difficulty urinating, sweating, dizziness, difficulty swallowing, wheezing, decreased appetite, and itching. Frequently, you may have side effects with one type of opiate, but not with a different one.
The biggest fear for patients and physicians, with opiate use, is that of addiction. Most people don’t realize that addiction is a mental problem. Very few patients, treated for medical problems, become addicts unless they have had previous problems controlling their drug or alcohol use.
We define addiction as the compulsive (obsessive) use of a drug which results in physical, psychological, or social harm to the patient, and an insistence by the patient on continued use despite that harm.
The vast majority of patients who take opiates will not become addicted. They will become physicaly dependent. Physical dependence means that if you stop taking the drug suddenly, you will suffer an abstinence syndrome. This may include diarrhea, cramping, flu-like symptoms, muscle aches, a rapid heartbeat or sweating. This withdrawal can be avoided by weaning from the drug (reducing the dose a little each day) over a two-week period of time.
Using opiates to control chronic pain is controversial. Many believe it is better to suffer than to take morphine. Some believe you can be taught to live with your pain. Others feel that pain is in your mind and that you can be taught to ignore it. We are more impressed with how narcotics have made many patients more functional and comfortable.
Before using opiates long term, you are encouraged to ask questions or to seek a second opinion.
We at the Northern California Medical Group, Inc. sometimes ask you to sign a narcotic contract before we will agree to give opiate drugs for chronic pain. A copy of the contract is available to download as a PDF file. Most computers have the software to download this file. You can get the software for free by clicking get Adobe PDF reader. You can download, read and print the narcotic contract by clicking here. You can also download, read a printable a description of pain medications and their uses by clicking here.
Below are some links to manufacturers sites for some of the more common medications. If you use the search engines, the sites are sometimes hard to find. The search engines contain hundreds of advertisements from attorneys promoting lawsuits against virtually all medications and drugs.
Information about most drugs can be found at the WebMD site. This is a paid advertising site but is excellent and thorough. As with all paid advertising sites, read the information critically. Advertisers have been known to slightly exaggerate in order to sell their product. Click here to go http://aolsvc.health.webmd.aol.com/home/default.htm
Click here for the official Bayer aspirin site http://www.bayeraspirin.com/
Bextra's official site by Pfizer is at http://www.bextra.com/
Click here for information on Celebrex by Pfizer http://www.celebrex.com/
For a downloadable file about Pfizer's Feldene, click here http://www.pfizer.com/download/uspi_feldene.pdf
Abbott Laboratories provides information about Mobic at http://www.mobictablet.com/mobicWeb/Controller.jpf
The official Motrin site can be reached by clicking here http://www.jnj.com/index.jsp?content=product/brands/MOTRIN.htm
Click here for the official Roche site on Naprosyn http://www.rocheusa.com/products/naprosyn/
Click here for the official Merck site on Vioxx http://www.vioxx.com/rofecoxib/vioxx/consumer/index.jsp