Pain medication delivery

Pain medications can be delivered by a number of different methods. The choices made for each person will depend on the nature of the pain being felt, and other circumstances of cancer treatment. Also, at any given time, people with cancer may be using several of these pain medication delivery methods to manage pain:

1. Oral
   
   This includes tablets, pills, capsules, and liquids that are meant to be swallowed.
   Oral medications -- and almost all medications are made in this form as well as others -- are preferred because they are the easiest and most convenient method. These medications may be short- or long-acting (timed release), and they enter the gastrointestinal tract immediately.
   
   
2. Oral Transmucosal
   
   These medication are administered in the mouth but are meant to be absorbed through the oral mucosa in the mouth--not swallowed. These delivery routes include the following:
   
   
   • transmucosal - medications in lozenge form are taken this way, notably the opioid medication used for breakthrough pain, Actiq®, which is a lozenge on stick that the patient moves around inside his mouth. Saliva dissolves the medication and it very quickly enters the bloodstream.
   
   
   • sublingual - medications are placed under the tongue and absorbed. The medication most commonly administered this way is nitroglycerin, in tablet form, but sometimes certain opioid medications in liquid form are administered sublingually in people who are unable to swallow medication or who have poor venous access.
   
   
3. By Injection
   
   Many pain medications are administered by injection, either because a particular medication should not be taken by mouth, or because the particular drug is works best if administered this way. There are three basic ways to receive medication by injection:
   
   
   • intravenous (IV) - medication enters the bloodstream quickly through a vein. This is a useful method when a patient cannot swallow oral medications, and sometimes pain relievers work fastest when injected. Intravenous administration can also be used over a period of time, when a steady level of pain reliever is needed. In some cases notably following surgery, PCA - patient-controlled analgesia - is used. This is a pump system that delivers pain medication and allows the patient to retain a measure of control over his or her pain management. When pain is felt or expected (such as when a person moves or walks), the PCA control button can be pushed, providing an extra dose of medication.
   
   
   • intramuscular (IM) - a needle with pain medication is injected into a muscle. This is not often the best choice for administering pain medications because the drug may not be evenly absorbed into the bloodstream, and because it is generally a slow approach to pain relief, with at least 30 minutes needed before the medication begins to work. Additionally, it can be particularly uncomfortable for patients. If you are routinely given pain medication by intramuscular injection, ask why, and ask for other options.
   
   
   • subcutaneous (SQ) - a needle with pain medication is inserted just under the skin into the fatty tissue there, usually in an area of the body where there is sufficient fat to make this approach minimally painful, such as the abdomen or the thigh. Some medications should not be taken orally, and in some instances, the subcutaneous approach is best. Also, if using an intravenous approach is not desirable or practical, subcutaneous administration is useful.
   
   
4. Transdermal
   Transdermal means “through the skin,” and in cancer pain, this means the use of a medicated “patch” that is affixed to the skin. The transdermal patch is designed to deliver medication slowly through the skin for a long period of time, usually 48 to 72 hours. It is important to know that it takes some time, sometimes as long as 12 hours, before the patch has reached its full pain-relieving capacity.  Duragesic®, a transdermal patch that contains the opioid fentanyl, is commonly used to treat chronic cancer pain, and it is available in a variety of strengths.
   
   
5. Rectal
   Opioid medications, notably morphine, oxymorphone and hydromorphone, are sometimes administered through the rectum in patients who are unable to take pain medications orally. Medications given rectally are administered in the form of a suppository (a waxy or gelatin capsule that quickly dissolves), or by the use of a needle-less injection. Rectal administration can provide quick pain relief but absorbtion in the rectum is variable and so is the amount of pain relief provided.
   
   
6. Infusion pump
   This method administers pain medications through a catheter near the spine. The other end is connected to a pump with pain medication that is programmed to deliver medication over a period of time. These pumps can be placed internally or externally. Infusion pumps may be an efficient and effective choice if your cancer-related pain is expected to last for a long time. Discuss this approach with a pain management specialist.

It's important to understand that many people with cancer will use one or more of these methods to achieve good quality pain management. Working with your health care provider and discussing your pain needs is the best way to approach decision-making about which medication delivery methods are best for you.