Hylan G-F 20 belongs to the group of medications known as synovial fluid replacements. It is used to relieve the symptoms of osteoarthritis (a condition causing joint "wear and tear" and pain) in the hip, ankle, shoulder, and knee joints. It works by mimicking the body's own synovial fluid (a fluid that lubricates and cushions the joints). Relief from pain can last up to 6 to 12 months.

Your doctor may have suggested this medication for conditions other than the ones listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are being given this medication, speak to your doctor. Do not stop using this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to use this medication if their doctor has not prescribed it.

This medication is injected into the joint that is affected by osteoarthritis. Your doctor or a trained health care professional will give you the injection, usually at a clinic. The dose depends on the location of the arthritis.

For osteoarthritis of the hip, ankle, or shoulder, the usual dose is a single injection into the affected joint. This dose can be repeated after 1 to 3 months if the first dose doesn't provide enough relief.

For osteoarthritis of the knee, the usual dose is 1 injection per week into the knee joint for a total of 3 weeks. If this first set of injections doesn't provide enough relief, a second set of 3 weekly injections can be given, provided at least 4 weeks have passed since the last treatment. The maximum recommended dose is 6 injections within 6 months.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are receiving the medication without consulting your doctor.

It is important to receive this medication exactly as prescribed by your doctor. If you miss an appointment for a dose of the injection, contact your doctor as soon as possible.

Store this medication at room temperature, do not allow it to freeze, and keep it out of the reach of children.

Each mL of sterile, nonpyrogenic, elastoviscous fluid contains hylan 8 mg. Nonmedicinal ingredients: disodium hydrogen phosphate, sodium chloride, sodium dihydrogen phosphate hydrate, and sterile water for injection.

Hylan G-F 20 should not be used by anyone who:

• is allergic to hylan G-F 20 or to any of the ingredients of the medication
• is allergic to products from birds, such as feathers, eggs, and poultry
• has a skin disease or infection near the planned injection area
• has an infected or severely swollen joint
• has fluid that doesn't flow properly in the veins or lymphatic system of the leg to be injected

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• mild pain, redness, heat, or swelling around the area of injection

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• burning, prickling, or tingling sensations in the hands or feet
• continued pain, swelling, redness of the affected joint with or without a fever
• dizziness
• fever or chills
• flushing or swelling of the face
• headache
• muscle cramps
• nausea
• swelling of the hands, feet, or ankles
• tiredness

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of an allergic reaction (e.g., hives; difficulty breathing; swelling of the face, tongue, or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Activity level: For a few days after receiving the injection, avoid strenuous activities such as jogging, tennis, heavy lifting, or standing for a long time. Consult your doctor before restarting these activities.

Pregnancy: The safety and effectiveness of using this medication during pregnancy have not been established. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if hylan G-F 20 passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children under 18 years of age.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. In many cases, interactions are intended or are managed by close monitoring. Speak to your doctor about how any drug interactions are being managed or should be managed.