Ziconotide

(zih-cone-uh-tide)

Trade/other name(s): Prialt

Why would this drug be used?

Ziconotide is used to manage severe chronic pain when other pain relievers have not worked.

How does this drug work?

Ziconotide is a pain reliever (non-opioid analgesic) that is given directly into the fluid around the spinal cord. This is a special way of giving a medicine, known as intrathecal injection. Ziconotide appears to block calcium channels that bring pain messages from the body to the brain. When given with opioid pain medicines, it makes them work better than when they are given alone.

Before taking this medicine

Tell your doctor…

• If you are allergic to anything, including medicines, dyes, additives, or foods.
• If you have ever had a mental health problems, especially if you have had psychosis, which may include having hallucinations or being out of touch with reality. Because ziconotide may cause this problem to happen again, people who have had psychosis should not take this drug.
• If you are taking any sedatives, tranquilizers, opioid pain medicines, antidepressants, antipsychotics, or any other medicine that may affect the brain or nervous system. You may have an increased risk of confusion, dizziness, or other side effects from this medicine.
• If you have any blockages around the spinal cord. The drug may not be able to circulate freely in the spinal fluid and could cause problems.
• If you have any problems with bleeding, such as hemophilia or von Willebrand disease. Ziconotide may increase your bleeding risk.
• If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. There may be an increased risk of harm to the fetus if a woman takes this drug during pregnancy.
• If you are breast-feeding. It is not known whether this drug passes into breast milk. If it does, it could harm the baby.
• About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

This drug may make you drowsy. This can add to the effects of other medicines or substances that make you sleepy or less alert, such as:

• anti-anxiety drugs (tranquilizers or sedatives)
• sleeping pills
• muscle relaxers
• barbiturates
• anti-seizure medicines
• opioid pain medicines
• anesthetics
• antidepressants such as amitriptyline, desipramine, doxepin, imipramine, nortriptyline
• anti-psychotic drugs
• certain anti-nausea medicines
• alcohol

Because these drugs affect the brain or nervous system, you may have a higher risk of confusion, dizziness, and other such effects while you are taking ziconotide.

Check with your doctor, nurse, or pharmacist about other medicines, vitamins, herbs, and supplements can cause problems with this medicine.

Interactions with foods

No serious interactions with food are known at this time. Check with your doctor, nurse, or pharmacist about whether foods may be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

Ziconotide is given through a thin tube or catheter into the intrathecal space (around the spinal cord) using a special pump for continuous infusion. The pump may be internal, implanted under the skin, or external, carried in a bag. The starting dose is increased as needed based on your pain relief. The pump must be refilled after 2 weeks and then again every 40 to 84 days, or more often if needed.

Be sure that you know how to use the pump and how to reach someone for help if you have any problems with the pump or tubing at any time of the day or night.

Precautions

Do not drive, operate hazardous machinery, or do tasks that require you to be alert while receiving ziconotide intrathecal injection. People have passed out while taking this medicine.

Ziconotide intrathecal injection can cause severe psychiatric (mental) symptoms and neurological (nervous system) problems. Tell your doctor right away if you start seeing, hearing, or feeling things that others cannot, or if you have trouble thinking or remembering things.

Call the doctor if you become weak, extremely tired, confused, disoriented, less alert, depressed, suicidal, or notice strange feelings in your mouth or throat. The drug can be stopped if needed.

Your doctor will likely test your blood throughout your treatment, looking for possible effects of the drug. Based on the test results, you may be given medicines to help treat any effects. Your doctor may also need to reduce your dose of this drug, or even stop it altogether.

Let your doctor or nurse know right away if you have trouble with or questions about the external pump. If the tubing comes apart and germs get in, a serious infection can result.

Tell your doctor right away if you develop nausea, vomiting, seizures, fever, headache, or stiff neck as this may be due to a serious infection caused by the catheter in your spinal fluid (meningitis).

Call your doctor if you have muscle aches or soreness, or if your urine turns dark in color.

Be sure your doctor knows about all the drugs you are taking. Ziconotide intrathecal injection can make you even less alert if you also take other drugs which affect your brain and nervous system.

When you start ziconotide, do not stop any of your other pain medicines without first checking with your doctor. You will probably need other pain medicines while you are on ziconotide, because severe cancer pain usually takes more than one medicine to control.

Most cancer pain can be controlled. Keep your doctor or nurse informed about how well your pain medicines are working and any side effects you are having. Your cancer team may need to adjust your medicines several times before they find the medicines that work best for you.

If you have chronic cancer pain, talk to your doctor about taking your other pain medicines on a regular schedule to keep pain from worsening. If you wait until the pain is bad, it takes more medicine to get it under control. If pain comes back between doses, talk to your cancer team about changing your medicine or adding an extra one for "breakthrough" pain.

Side effects are not as much of a problem when the drug dose is slowly increased over 3 weeks.

Possible side effects

You will probably not have most of the following side effects, but if you have any, talk to your doctor or nurse. They can help you understand the side effects and cope with them.

Common

• dizziness
• confusion*
• headache
• nausea*
• feeling tired and weak

Less common

• diarrhea
• vomiting*
• sleepiness
• unsteadiness or trouble walking
• trouble remembering things*
• problems with vision (seeing), and abnormal eye movements
• problems with speaking
• hallucinations (seeing or hearing things that aren't there)

Rare

• fever
• appetite loss
• urinary retention (trouble passing urine)
• hallucinations*
• paranoia (being fearful)
• mental or emotional distress
• nervousness
• feeling like you are moving when you are not, or that the room is spinning (vertigo)
• amnesia
• eye movements get jerky or shaky
• numbness and tingling or increased sensation in hands and feet
• infection around the spinal cord and brain (meningitis)*
• breakdown of muscle fibers leading to kidney damage*

*See "Precautions" section for more detailed information.

There are other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA approval

Yes – first approved in 2004.

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.