Routes of drug administration

The choice of a route of administration is very important, because it can influence the whole pharmacokinetic process of the molecule introduced into our body.

The choice of how to administer a drug depends mainly on the target to be hit with that particular active ingredient; for example, in the presence of a cutaneous mycosis or an allergic form of the skin, the transcutaneous route of administration will be chosen.

Furthermore, the following must be taken into account:

• the pharmaceutical form;
• the rapidity in reaching a certain effect (for example during an emergency treatment, such as anaphylactic shock, a route of administration is used that allows an immediate achievement of a certain effect);
• the duration of the effect and finally the patient's health conditions.

The main routes of administration are:

• Enteral routes of administration (oral, sublingual, rectal)
• Parenteral routes of administration (intravascular, intramuscular, subcutaneous, intradermal)
• Inhalation route of administration
• Transcutaneous route of administration

There are also other routes of administration such as intradermal, intrathecal, intra-articular, intra-cavitary, intra-arterial and transmuscular.

 

There route of intradermal administration it is used for allergy testing and the maximum injectable volume is 0.1 - 0.2 ml.

 

There intra-arterial route of administration it is applied in particular cases, such as when you want to obtain high concentrations of the drug in certain organs (eg angiography).

 

There route of intrathecal administration involves the injection of the active principle directly into the CSF that flows into the cerebral ventricles and surrounds the spinal cord. The drug administered easily overcomes the BEE (Blood-Brain Barrier). This route is widely used in surgical interventions that require local anesthesia (anesthesia spinal or epidural).

 

ADMINISTRATION FOR OS

variable absorption, which depends on many factors
the effects appear after at least 45-60 minutes it is the cheapest way

and safer

possibility of using

RETARD PREPARATIONS

the patient must be awake and cooperative
incomplete absorption may not allow reaching the minimum effective concentration
first pass effect

RECTAL ADMINISTRATION

variable and incomplete absorption it has a lower latency of action than the oral route partial first pass effect

SUBLINGUAL ADMINISTRATION

rapid absorption the effect appears after a few minutes

used in an emergency

avoids the first pass effect

correct intake of the drug
increased risk of side effects

INTRAVENOUS ADMINISTRATION

100% absorption immediate effects used in an emergency, large volumes can be injected

diluted irritants (KCl)

increased risk of side effects
the infusion must be slow
not usable for oily or insoluble substances

INTRAMUSCULAR ADMINISTRATION

Absorption:
quick for aqueous solutions
slow and prolonged for slow release preparations moderate volumes can be used
it is used to administer
oily substances not usable if the pc. He is on anticoagulant therapy for pain or necrosis (rare) using irritants

SUBCUTANEOUS ADMINISTRATION

absorption:

quick for

aqueous solutions

slow and prolonged for slow release preparations it is used for insoluble solutions and for implantation
of solid pellets not usable for large volumes pain or necrosis (rare) using irritants

 

Other articles on "Drug Administration Routes"

1. Pharmacology
2. Enteral routes of administration