Synvisc (hylan G-F 20) is a viscous but also elastic fluid with a high content of hylan A and B molecules which are derivatives of hyluronan. Hylan G-F 20, is a unique chicken combs extract and it is chemically cross-linked that is; a long-chain polymer with a repeating series of disaccharide units of Na-glucuronate-Nacetylglucosamine.
Who is it recommended for?
This is an injectable treatment for individuals with joint problems especially osteoarthritis, a condition whereby a person experiences pain at their joints due to poor amount or quality of synovial fluid. Synvisc, supplements the knee joint with lubrication and cushion fluid since the natural occurring synovial fluid is of low quality or level in return providing relief from the pain.
How do you come to the conclusion, that a patient is ready for Synvisc?
Synvisc is usually given to patients after they have failed to respond to conservative nonpharmacologic therapy or simple analgesicspain. Including other treatments you can impart the patient to try before or as alternatives of using Synvisc such as:
- ‘Nonsteroidal anti-inflammatory’ (NSAI1D) agents and other treatments for reducing inflammation like asprins
- Physical therapy or
- Use of another knee- injectable drug like Corticosteroids
- Having decided to treat the patient with Synvisc, you need to further asses them, make yourself aware of:
- Whether they have any allergies for example, to hyluronan, birds, feathers or other poultry products as well as their reaction to them too. Anaphylactic and anaphylactoid reaction, anaphylactic shock and angioedema are some of the known allergic responses associated with Synvic
- An infection around the knee joint with the problem or the skin around the joint
- Blood illnesses, clots or circulation problems especially around your legs.
- Since there is no knowledge of Synvisc effects to unborn babies and pregnant women, ensure your patient is not pregnant and they should tell you in case they are planning to.
- Synvisc effects to babies is also not known, therefore get informed whether the patient is breastfeeding as the hyluronan will pass through the breast milk.
- Typically, Synvisc is not given to pediatric patients, persons under the age of 21 years, as the effect on them is yet to be established.
Dosage and administration:
Generally, for productive results, Synvisc is administered by an intra-articular injection once in a week for three weeks and each time you should ensure strict ascetic technique. However, do not inject Synvisc extra-articularly or through the synovial tissues and capsule as it may result to adverse results in the injected area. Also, intravascular injections may cause major adverse effects.
Here is a simple procedure which you can follow to make certain of success administration:
- Use an 18-22 gauge needle. Remove synovial fluid or effusion before injecting the Synvisc to the patient.
- The same size of gauge (18-22) should be used to administer the drug. However, you should a different and new gauge to administer Synvisc, it should be only 2ml content into one knee.
- To minimize the product leakage, twist the tip of the cap before you pull it off.
- Synvisc is then injected to the joint area with the problem. To ensure there is no leakage during administration, secure the needle tightly as you steadily hold the luer hub.
Nevertheless, you should avoid breaking the syringe by putting too much force while attaching the needle or removing the needle guard. In addition, you need to be more cautious especially when there are signs of lymphatic or venous stasis at the leg that is to be treated.
When does the patient start feeling better?
Our bodies being different, relief from pain will vary however, after the dose is over, most patients are known to experience relief after six months and some after the first 6-12 weeks from the first injection. Although, it is essential that a patient finishes the dose regardless of how soon they feel well before completion of the dose.
After administering Synvisc to your patient, advise them to avoid any strenuous activities such as participating in sports, carrying of heavy items or standing for more than an hour.
Do not provide a patient with Synvisc that is from a damaged or already opened package also, ensure it is original. It is normally provided in a glass syringe of 2.25ml with 2ml or 16 gm of sterile and nonpyrogenic content.
Use the syringe immediately you get it out from its package plus, the content in it is for a single use. Synvisc should be stored away from direct light and under room temperature; do not freeze.
Inform the patient that they should not use skin disinfectants with quaternary ammonium as it would react with hyaluronan and precipitate on the skin.
Possible side effects of Synvisc
Here are a few of the known side effects the patient may experience:
- Muscle pain which may cause trouble walking
- Feeling fatigue
- Headache, dizziness or both
- Swelling, warmth and redness where the drug was administered
- Skin irritation on the skin around the joint are
- Numbness, feeling tingly
- Fever, nausea, chills
Advise the patient that in case of even more serious side effects like joint effusion, swelling or pain at the joint; or reactions such as swelling of the tongue, lips and throat, hives and breathing difficulty, they should visit the emergency room or call you immediately.
Overdose and other interactions:
Any other interactions of Synvisc and food or other substances have not been established. Overdoses on the other hand, are rare occurrences as administering of the drug is done by a certified medical officer. However, in case it happens, medical attention should be sought immediately.