Parenteral
route
Parenteral route: - A drug to be injected by parenteral route, must
be sterile and little irritant. The injection requires a syringe and a needle
or a device of administration already set up.
One distinguishes:
1. Intradermal route, especially
used for intradermal reactions.
2. Subcutaneous route
The volume of fluid injected is limited and the rate of resorption variable, depending on local factors: sclerosis, circulatory state (vasodilation, vasoconstriction). Heparin and insulin are among the drugs generally administered drugs by subcutaneous route.
The volume of fluid injected is limited and the rate of resorption variable, depending on local factors: sclerosis, circulatory state (vasodilation, vasoconstriction). Heparin and insulin are among the drugs generally administered drugs by subcutaneous route.
3.
Intramuscular route
The rate of resorption is fast and it is possible to inject aqueous or oily solutions.
There are delayed preparations gradually releasing over one or many weeks the active product from the anatomic site of injection into the circulation, sexual hormones or neuroleptic agents for example. The intramuscular injection should not be made in a vessel, nor in contact with a nerve. It is contra-indicated if the patient is undergoing anticoagulant therapy.
The rate of resorption is fast and it is possible to inject aqueous or oily solutions.
There are delayed preparations gradually releasing over one or many weeks the active product from the anatomic site of injection into the circulation, sexual hormones or neuroleptic agents for example. The intramuscular injection should not be made in a vessel, nor in contact with a nerve. It is contra-indicated if the patient is undergoing anticoagulant therapy.
4.
Intravenous route
There are two possibilities: direct injection with the syringe or administration by perfusion.
The bioavailability is by definition 100%; it is necessary however to pay attention to the speed of administration because it should not be:
There are two possibilities: direct injection with the syringe or administration by perfusion.
The bioavailability is by definition 100%; it is necessary however to pay attention to the speed of administration because it should not be:
o too
rapid, which can be the case with direct administration by a syringe, with risk
of severe reactions.
o too
slow, as observed during certain perfusions, because if the rate of
elimination is rapid, the effective therapeutic concentration can
not be reached.
Oily solutions should not be given by intravenous route.
There are implantable devices for intravenous administration, set up surgically and used for long courses, in particular for chemotherapy. It gives intravenous access with an administration of subcutaneous type.
Oily solutions should not be given by intravenous route.
There are implantable devices for intravenous administration, set up surgically and used for long courses, in particular for chemotherapy. It gives intravenous access with an administration of subcutaneous type.
5.
Intraarterial route
It is little used, some examples of intraarterial administration: a vasodilator for arteritis, a thrombolytic to dissolve a clot, an antineoplastic for localized treatment of a cancer.
It is little used, some examples of intraarterial administration: a vasodilator for arteritis, a thrombolytic to dissolve a clot, an antineoplastic for localized treatment of a cancer.
6.
Routes of particular local
injections
They are used to introduce a drug for diagnosis or treatment purposes in particular anatomical sites, for examples by intraspinal, intra-articular, intrapleural, intraperitoneal injections.
They are used to introduce a drug for diagnosis or treatment purposes in particular anatomical sites, for examples by intraspinal, intra-articular, intrapleural, intraperitoneal injections.
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