Baclofen Injection USP: Uses, Side Effects and Dosage

Serious Warnings and Precautions

What is Baclofen Injection USP used for?

Baclofen Injection USP is used in adults to manage muscle spasms and stiffness due to spinal cord injury or multiple sclerosis.

How does Baclofen Injection USP work?

Baclofen Injection USP belongs to a group of medicines called muscle relaxants. The exact way it works is not fully known. However, it may have benefits on muscle spasms and pain to improve overall mobility. The Baclofen Injection USP solution gets delivered into the fluid space around the spinal cord via a special pump. This pump is implanted under the skin of the abdomen. From the pump a constant amount of the solution is delivered into the fluid space around the spinal cord.

What are the ingredients in Baclofen Injection USP?

Medicinal ingredient: Baclofen.

Non-medicinal ingredients: Sodium chloride and water for injection.

Baclofen Injection USP comes in the following dosage forms:

Solution: 2 mg / mL of baclofen in 5 mL ampoules.

Do not use Baclofen Injection USP if:

• you are allergic to baclofen or any of the other ingredients in Baclofen Injection USP. If you think you may be allergic, ask your healthcare professional.

In addition, Baclofen Injection USP is only for intrathecal use only (into the fluid space around the spinal cord). Do NOT use of Baclofen Injection USP via any other routes to avoid the risk of unwanted serious side effects.

To help avoid side effects and ensure proper use, talk to your healthcare professional before you take Baclofen Injection USP. Talk about any health or conditions problems you may have, including if you:

• have any kind of infection.
• have Parkinson’s disease or certain mental illnesses accompanied by confusion.
• have a mental illness.
• have a history with epilepsy (seizures).
• have or have had heart problems.
• have or have had kidney problems.
• have or have had liver problems.
• have breathing or lung problems.
• have or have had an ulcer in your stomach or intestines.
• have abnormal blood circulation in your brain.
• have a history of a condition called autonomic dysreflexia. The symptoms of autonomic dysreflexia include sudden episodes of high blood pressure, anxiety, excessive sweating, "goose flesh", a pounding headache, and an unusually slow heartbeat due to an overreaction of your nervous system to stimuli such as distension of the bladder and intestine, skin irritation and pain.
• have had previous withdrawal symptoms after taking baclofen, the medicinal ingredient in Baclofen Injection USP.
• are pregnant or planning to become pregnant. Your healthcare professional will discuss and consider the benefit and risks to you and your baby.

Other warnings you should know about:

While you are using Baclofen Injection USP, talk to your healthcare professional immediately if you:

• have pain in your back, shoulders, neck, and buttock (a type of spinal deformity called scoliosis).
• thoughts of harming or killing yourself at any time; Also, ask a relative or close friend to call your healthcare professional if they are worried about any changes in your behaviour and ask them to read this leaflet.

Breastfeeding

You should talk to your healthcare professional, if you are breastfeeding or you want to breastfeed. Only very small quantities of Baclofen Injection USP pass into the breast milk. Ask your doctor if you want to breastfeed.

Driving and using machines: Baclofen Injection USP can cause drowsiness, sleepy, loss of coordination, and blurred vision. Before you drive or do tasks that require special attention wait until you are feeling normal again.

Check-ups and testing: Your healthcare professional will regularly monitor and assess your health throughout your treatment with Baclofen Injection USP. This includes close monitoring at the start of your treatment after the pump is implanted and when your dose is altered. They may also monitor the following:

• if the implanted pump is working properly;
• any changes in your behaviour or mood;
• your heart and blood vessels;
• your breathing and lungs;
• your kidneys;
• the presence of any infections; and
• for possible side effects.

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.

The following may interact with Baclofen Injection USP:

• other muscle relaxants, medicines used to treat muscles spasms and stiffness (e.g., tizanidine);
• medicines used to treat Parkinson’ disease (e.g., levodopa and carbidopa);
• medicines used to treat mood disorders (e.g., antidepressants and lithium);
• medicines that lower blood pressure including medicines used to treat high blood pressure;
• other drugs which affect the kidney
• opioids, medicines used to manage pain (e.g., fentanyl and morphine);
• anesthetics, medicines used to help you sleep or calm you down during surgery (e.g., propofol);
• medicines which slow down the central nervous system, e.g. sedatives (some of these can be bought over the counter)
• analgesics, medicines used to treat pain;
• medicines used to help reduce anxiety and / or treat mental illnesses (e.g., barbiturates, benzodiazepines, hypnotics, anxiolytics, and neuroleptics);

• alcohol: Be careful if you drink alcoholic beverages during treatment with Baclofen Injection USP as you may feel more sleepy or dizzy than usual.

Ask your healthcare professional if you are unsure, or for advice before taking other medicine.

How to take Baclofen Injection USP:

• Your healthcare professional will prepare and give you Baclofen Injection USP using special equipment. At first, your healthcare professional will inject a small amount of Baclofen Injection USP into the fluid space around your spinal cord (intrathecally) to see how you react. If they think Baclofen Injection USP is right for you, they will implant the pump under the skin of your abdomen. This pump will be programmed to give you your dose of Baclofen Injection USP.
• To closely monitor your health, you will need to stay in the hospital at the start of your treatment or even longer.
• If your pump is not working or if you notice any withdrawal symptoms, get medical help right away. See the Serious Warnings and Precautions box, above, for more information.
• If your condition is not improving or if you start having muscle spasms again, contact your healthcare professional right away.

Usual Dose:

Your healthcare professional will determine the right dose of Baclofen Injection USP for you.

It may take several days to find the right dose with the desired effect. This will depend on your condition, if you take other medication, and how you react to Baclofen Injection USP. Your healthcare professional will keep a close watch on you during this time. After that, your healthcare professional will still want to see you regularly to check your progress and make sure your pump is working well.

Overdose:

It is important that you and those caring for you recognize the signs of an overdose. This may appear gradually or suddenly, especially at the start of your therapy. The signs of an overdose with Baclofen Injection USP include:

• unusual muscle weakness,
• decreased muscle tone,
• sleepiness,
• drowsiness,
• lightheadedness,
• dizziness,
• excessive salivation,
• nausea,
• vomiting,
• difficulties in breathing,
• seizures,
• loss of consciousness,
• abnormally low body temperature (hypothermia),
• fast heartbeat (tachycardia),
• ringing in the ears (tinnitus),
• coma.

Missed Dose:

If you miss a dose, (e.g., if your pump is not working properly or if your pump is not delivering the right dose) serious medical problems may occur. See the Serious Warnings and Precautions box, above, for more information. Tell your healthcare professional right away if you have any withdrawal symptoms or if you think your device is not working properly.

What are possible side effects from using Baclofen Injection USP?

These are not all the possible side effects you may have when taking Baclofen Injection USP.

If you experience any side effects not listed here, tell your healthcare professional. Some side effects could be associated with the delivery system.

Side effects of Baclofen Injection USP include:

• drowsiness, muscle weakness;
• feeling of anxiety;
• sedation and weariness (exhaustion);
• weakness in the legs;
• stiffness in the muscles;
• dizziness / lightheadedness;
• headache, sleepiness;
• feeling sick and / or vomiting;
• tingling in the hands and feet;
• insomnia, slurred speech (difficulty speaking);
• pneumonia;
• weakness, chills, fatigue, pain;
• dry mouth;
• skin rash and / or itching;
• swelling of the ankles, feet, or lower legs;
• puffy face;
• unusual nervousness or restlessness, confusion / disorientation;
• constipation, diarrhea, decreased appetite, excessive salivation;
• fever / shivering;
• urinary problems, sexual difficulties;
• Mood or mental changes, paranoia, feeling extreme happiness (euphoria);
• loss of muscle coordination (ataxia);
• abnormally low body temperature;
• memory loss;
• continuous uncontrollable eye movements;
• decreased sense of taste, difficulty in swallowing;
• abdominal pain;
• hair loss, excessive sweating;
• restlessness (dysphoria);
• abnormally slow breathing rate (bradypnea);
• increase in sideways curvature of the spine (scoliosis);
• inability to achieve or maintain an erection (erectile dysfunction).

Serious side effects and what to do about them

Serious side effects and what to do about them

Serious side effects and what to do about them

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.

Reporting Side Effects

Storage:

Store Baclofen Injection USP ampoules between 15-30°C. Protect from heat and freezing. Do not heat sterilize.

Keep all medicines out of reach and sight of children.

Do not use outdated medicines. Discard any unused portion and any outdated medicines safely out of the reach of children or take them to your pharmacist who will dispose of them for you.

If you want more information about Baclofen Injection USP:

• Talk to your healthcare professional;

• Find the full Product Monograph that is prepared for healthcare professionals and includes the Patient Medication Information by visiting the Health Canada website (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug- product-database.html); or by calling 1-866-399-9091.

  JAMP Pharma Corporation

  1310 rue Nobel

  Boucherville, Québec

  J4B 5H3

Last Revised: NOV 29, 2024