Types of Syringes

Syringes are an important part of disease treatment and prevention, and it is imperative to understand the different types and uses of syringes to ensure that injectable medications are properly administered. Syringes come in a variety of types and sizes, which are specific to the intended delivery method. Also, syringes with safety features have been created to prevent accidental injuries and exposure to hazardous bodily fluid.

Syringe Features

• Conventional syringes consist of four main parts: a cap, a needle, a barrel and a plunger. The cap of the syringe is used to cover the needle. The barrel of the syringe holds the fluid intended for injection and the plunger pushes the fluid out of the syringe. The needle of the syringe can be permanently attached, or it may be detachable.

Insulin Syringe

• The barrel of an insulin syringe is often smaller than the barrel of other types of syringes, because it is intended to hold less fluid. Also, the needle of an insulin syringe is shorter, because it is meant to be injected subcutaneously (under the skin). Insulin is unique in the way that it is measured. It is the only medication in which the units of measurement are simply called "units." Thus, the barrel of an insulin syringe measures the amount of insulin in units rather than the amount of fluid in milliliters (ml).

Mouth Syringe

• Mouth syringes are used for the administration of liquid medications. Typically, mouth syringes are used by children. But, syringes are also used by adults who are unable to swallow the solid form of a medication. Mouth syringes come in different barrel sizes, such as 1 ml and 5 ml. Some medications, such as reconstitutable Tamiflu, come with a mouth syringe that measures the amount of medication drawn into the barrel, in milligrams (mg), rather than the amount of liquid, in milliliters.

Allergy Syringe

• When used for allergy treatment, an allergy syringe is meant to be injected subcutaneously. However, some allergy syringes have a longer needle, which is required for medications that are meant to be injected intramuscularly (into the muscle), such as B-12. Retail pharmacies commonly dispense allergy syringes for intramuscular injections. Additionally, allergy syringes can have a larger barrel than other syringes, which is required to administer medications that are given in larger doses.

Safety Syringe

• Syringes that are "safety-engineered" are called safety syringes. Safety syringes provide extra protection from accidental needle stick injuries and exposure to bloodborne pathogens. Some safety syringes have a protective needle sleeve, which locks into place over the needle, to ensure that the needle covering does not come loose. Also, some safety syringes have a retractable needle. When the plunger of the syringe pushes the entire contents out of the barrel, the needle quickly retracts back into the syringe.