Pain Medications

This section describes the use of medicines to control pain. The source of the pain helps determine the best way to treat it.

Needles

Children with cancer have many needles that cause pain for a short time. Some small quick needle procedures tend to be well tolerated once distraction and other coping strategies are learned. Some procedures also require drug treatment to reduce or eliminate the pain.

If possible, more painful procedures (such as bone marrow biopsies or lumbar punctures) should be done in a place other than the child's room. The child's room should be kept as a safe haven, where the child knows pain will not be inflicted.

EMLA® is a local anaesthetic cream which works very well when needles are given into tissue just under the skin. It is put on the skin before a procedure is done and works to numb or "freeze" the area so the needle is not felt. For example, starting an intravenous catheter, placing a needle in a Port-a-Cath®, or inserting a needle for a blood sample or cancer medicines can be much less painful with EMLA®. Many children can also have a lumbar puncture (spinal tap) quite comfortably with EMLA®.

EMLA® contains two very well established and researched drugs, lidocaine and prilocaine. These are blended in a way to make them more effective than each one by itself. EMLA® is applied in a thick "blo" at the spot where the needle will go in, at least one hour ahead of time (90 minutes for dark-skinned patients). It should NOT be rubbed in. It is then covered with an airtight bandage and the time is written on the dressing. This airtight bandage helps the medicine go further into the skin and freeze the deeper areas. The doctor or nurse then removes EMLA® and cleans the area before the needle is given. Children who have had a large number of needles without EMLA® may find it doesn't work perfectly at first, because they expect to have pain with their needles.

If you are applying EMLA® yourself, the package comes with detailed instructions. Your child's nurse can also help you, or answer questions you have about applying the cream.

For bone marrow aspirations and biopsies and some lumbar punctures, two other methods of pain control are required: local anaesthetics by needle and sedation.

Local anaesthetics by needle can be injected into deeper tissue first, so that the needle used for these procedures will not hurt. In this case, EMLA® is also used to make the local anaesthetic needle pain-free.

Sedation (especially "deep sedation" or "conscious sedation") is very helpful for children during more painful procedures. The goals of sedation are to have the child pain-free and comfortable for the short time of the procedure and awake as quickly as possible when the procedure is finished. Different combinations of drugs can be used intravenously (or occasionally by mouth) to do three things: reduce pain from the procedure, reduce anxiety or worry, and help the child forget unpleasant parts of the procedure. Intramuscular medications for sedation are not usually helpful. Two types of drugs are used in conscious sedation: a drug to remove anxiety and memory of the procedure (e.g. midazolam or diazepam); and a strong analgesic or anaesthetic (e.g. ketamine, fentanyl, alfentanil, morphine, or meperidine).

When this type of sedation is used, an anaesthetist, another physician, or a specially trained nurse carefully checks the child's blood pressure, pulse, breathing, and oxygen saturation during the procedure. Every child has a somewhat different response to sedative medications, so the anaesthetist will carefully adjust the dose to make sure the child is comfortable.

Occasionally, it may be better to have a procedure done in the operating room under general anaesthesia. This may occur if several procedures are to happen at the same time, or if a child is very sick. General anaesthesia is no more dangerous than other types of sedation, and in some hospitals is used for all bone marrow biopsies.

Continuing Pain

Children may also have pain from cancer that goes on for a long time (days, weeks, or months). This pain may be caused by growth or spread of the disease, or by side effects of treatment. The first step is to find out what is causing the pain, then to do everything possible to reduce or eliminate the pain.

Medicine for continuing pain should be given regularly, to prevent the pain from coming back. Once pain gets out of control, it is harder to stop. It is important not to wait for the pain to return; if medicine is given before the pain is bad, it will work better and less will be needed.

In most cases, medicine for continuing pain can be given by mouth. This is the easiest, safest, and least expensive method. For mild pain, the first medicine tried is usually acetaminophen (Tylenol®, Panadol®), or a similar drug, given every four hours around the clock. In some cases, a longer acting drug (such as naproxen) can be given two or three times a day. If an acetaminophen-like drug isn't enough, a mild opioid or narcotic (such as codeine) can be given every four hours with acetaminophen. More severe pain may need a stronger medicine. Morphine is the most commonly-used strong pain medication, and is effective in most cases. It should usually be given every four hours around the clock, although sometimes a slow-release preparation such as MS-Contin® can be given twice a day. Occasionally, other similar drugs, such as hydromorphone (Dilaudid®), are used instead.

Pain from damaged nerves may be treated with other drugs, such as anti-convulsants like carbamazepine (Tegretol®) or anti-depressants like amitriptyline (Elavil®).

Different children will need different strengths of medicine. In almost every case, we can find the right level for each child. It is important NOT to give your child extra pain medicine on your own Ü for example, pain remedies that you can buy off the shelf. If you think your child is not getting enough pain medicine, be sure to talk to the doctor or nurse about it.

Many parents are frightened when morphine is suggested for their child. They think morphine is only used when children are about to die. Children may be treated with morphine at any stage of their disease, if they have strong pain. The use of morphine or other strong pain medicines has everything to do with how much pain a child has. It has nothing to do with his or her chance of survival.

Some parents worry about side effects of morphine, including addiction, constipation, nausea, itchiness, and sedation. Children who are on morphine gladly stop taking the drug once it is no longer needed. If morphine is stopped suddenly, a withdrawal reaction may occur because the child's body has become dependent on the drug. The child will become jittery, sweaty, and grumpy. That is why we reduce morphine slowly once the drug is no longer needed. Addiction is an excessive craving for a drug even if it is not needed for pain relief. This does not happen when morphine is given for cancer pain.

Unless prevented, constipation will occur in almost all children who take codeine or morphine for more than a few days. Constipation must be treated before it begins. Stool softeners such as Colace® and lactulose and bowel stimulants such as Senokot® are very helpful, and should be given routinely whenever opioid drugs are used.

Nausea can occur with morphine, but usually goes away in a few days or is easily treated with medications. Itchiness, if it occurs, also tends to go away in a few days. If not, there are drugs that may help stop the itch.

Some children may be sleepy the first few days they are on morphine. Sometimes they are just catching up on sleep they have missed. Sleepiness is rarely a problem once the right dose is found, and children can take morphine for months and be very alert. In addition, children whose pain is well-controlled with morphine are able to sleep better at night, because they are in less pain. In the rare cases when drowsiness is a problem, a stimulant drug may be given.

A concern of some parents is that their child will become used to morphine's effects. They worry that if morphine is used too early in the disease, it will not work well later on. Some children may need a larger dose of morphine after they have been on it for a while, but there is no upper limit to the amount of morphine that can be used. Giving a larger dose is not a problem.

In summary, when used properly, morphine is a safe, effective drug.