A route of administration in pharmacology and toxicology is the path by which a drug, fluid, poison, or other substance is taken into the body. Routes of administration are generally classified by the location at which the substance is applied. Common examples include oral and intravenous administration. Routes can also be classified based on where the target of action is. Action may be topical (local), enteral (system-wide effect, but delivered through the gastrointestinal tract), or parenteral (systemic action, but delivered by routes other than the GI tract).
1.1 By application location
1.1.1 Enteral/gastrointestinal 1.1.2 Parenteral
2 Choice of routes
2.1 Convenience 2.2 Desired target effect 2.3 Oral 2.4 Local 2.5 Inhalation 2.6 Parenteral
3 Research 4 See also 5 References 6 External links
Routes of administration are usually classified by application
location (or exposition).
The route or course the active substance takes from application
location to the location where it has its target effect is usually
rather a matter of pharmacokinetics (concerning the processes of
uptake, distribution, and elimination of drugs). Exceptions include
the transdermal or transmucosal routes, which are still commonly
referred to as routes of administration.
The location of the target effect of active substances are usually
rather a matter of pharmacodynamics (concerning e.g. the physiological
effects of drugs). An exception is topical administration, which
generally means that both the application location and the effect
thereof is local.
Administration through the gastrointestinal tract is sometimes termed enteral or enteric administration (literally meaning 'through the intestines'). Enteral/enteric administration usually includes oral (through the mouth) and rectal (into the rectum) administration, in the sense that these are taken up by the intestines. However, uptake of drugs administered orally may also occur already in the stomach, and as such gastrointestinal (along the gastrointestinal tract) may be a more fitting term for this route of administration. Furthermore, some application locations often classified as enteral, such as sublingual (under the tongue) and sublabial or buccal (between the cheek and gums/gingiva), are taken up in the proximal part of the gastrointestinal tract without reaching the intestines. Strictly enteral administration (directly into the intestines) can be used for systemic administration, as well as local (sometimes termed topical), such as in a contrast enema, whereby contrast media is infused into the intestines for imaging. However, for the purposes of classification based on location of effects, the term enteral is reserved for substances with systemic effects.
A medical professional injects medication into a gastric tube.
Many drugs as tablets, capsules, or drops are taken orally. Administration methods directly into the stomach include those by gastric feeding tube or gastrostomy. Substances may also be placed into the small intestines, as with a duodenal feeding tube and enteral nutrition. Enteric coated tablets are designed to dissolve in the intestine, not the stomach, because the drug present in the tablet causes irritation in the stomach.
Administering medication rectally
The rectal route is an effective route of administration for many
medications, especially those used at the end of
life. The walls of the rectum absorb many
medications quickly and effectively. Medications delivered to the
distal one-third of the rectum at least partially avoid the "first
pass effect" through the liver, which allows for greater
bio-availability of many medications than that of the oral route.
Needle insertion angles for 4 types of parenteral administration of medication: intramuscular, subcutaneous, intravenous and intradermal injection.
The parenteral route is any route that is not enteral (par- + enteral). Parenteral administration can be performed by injection, that is, using a needle (usually a hypodermic needle) and a syringe, or by the insertion of an indwelling catheter. Locations of application of parenteral administration include:
central nervous system
epidural (synonym: peridural) (injection or infusion into the epidural space), e.g. epidural anesthesia intracerebral (into the cerebrum) direct injection into the brain. Used in experimental research of chemicals and as a treatment for malignancies of the brain. The intracerebral route can also interrupt the blood brain barrier from holding up against subsequent routes. intracerebroventricular (into the cerebral ventricles) administration into the ventricular system of the brain. One use is as a last line of opioid treatment for terminal cancer patients with intractable cancer pain.
A transdermal patch which delivers medication is applied to the skin. The patch is labelled with the time and date of administration as well as the administrator's initials.
A medical professional applies nose drops.
Administering medication vaginally
epicutaneous (application onto the skin). It can be used both for local effect as in allergy testing and typical local anesthesia, as well as systemic effects when the active substance diffuses through skin in a transdermal route. sublingual and buccal medication administration is a way of giving someone medicine orally (by mouth). Sublingual administration is when medication is placed under the tongue to be absorbed by the body. The word "sublingual" means "under the tongue." Buccal administration involves placement of the drug between the gums and the cheek. These medications can come in the form of tablets, films, or sprays. Many drugs are designed for sublingual administration, including cardiovascular drugs, steroids, barbiturates, opioid analgesics with poor gastrointestinal bioavailability, enzymes and, increasingly, vitamins and minerals. extra-amniotic administration, between the endometrium and fetal membranes nasal administration (through the nose) can be used for topically acting substances, as well as for insufflation of e.g. decongestant nasal sprays to be taken up along the respiratory tract. Such substances are also called inhalational, e.g. inhalational anesthetics. intraarterial (into an artery), e.g. vasodilator drugs in the treatment of vasospasm and thrombolytic drugs for treatment of embolism intraarticular, into a joint space. Used in treating osteoarthritis intracardiac (into the heart), e.g. adrenaline during cardiopulmonary resuscitation (no longer commonly performed) intracavernous injection, an injection into the base of the penis intradermal, (into the skin itself) is used for skin testing some allergens, and also for mantoux test for tuberculosis intralesional (into a skin lesion), is used for local skin lesions, e.g. acne medication intramuscular (into a muscle), e.g. many vaccines, antibiotics, and long-term psychoactive agents. Recreationally the colloquial term 'muscling' is used.
intraocular, into the eye, e.g., some medications for glaucoma or eye neoplasms intraosseous infusion (into the bone marrow) is, in effect, an indirect intravenous access because the bone marrow drains directly into the venous system. This route is occasionally used for drugs and fluids in emergency medicine and pediatrics when intravenous access is difficult. Recreationally the colloquial term 'boning' is used. intraperitoneal, (infusion or injection into the peritoneum) e.g. peritoneal dialysis intrathecal (into the spinal canal) is most commonly used for spinal anesthesia and chemotherapy Intrauterine intravaginal administration, in the vagina intravenous (into a vein), e.g. many drugs, total parenteral nutrition Intravesical infusion is into the urinary bladder. intravitreal, through the eye Subcutaneous (under the skin). This generally takes the form of subcutaneous injection, e.g. with insulin. Skin popping is a slang term that includes subcutaneous injection, and is usually used in association with recreational drugs. In addition to injection, it is also possible to slowly infuse fluids subcutaneously in the form of hypodermoclysis. transdermal (diffusion through the intact skin for systemic rather than topical distribution), e.g. transdermal patches such as fentanyl in pain therapy, nicotine patches for treatment of addiction and nitroglycerine for treatment of angina pectoris. perivascular administration (perivascular medical devices and perivascular drug delivery systems are conceived for local application around a blood vessel during open vascular surgery).  transmucosal (diffusion through a mucous membrane), e.g. insufflation (snorting) of cocaine, sublingual, i.e. under the tongue, sublabial, i.e. between the lips and gingiva, nitroglycerine, vaginal suppositories
Physical and chemical properties of the drug. The physical properties are solid, liquid and gas. The chemical properties are solubility, stability, pH, irritancy etc. Site of desired action: the action may be localised and approachable or generalised and not approachable. Rate of extent of absorption of the drug from different routes. Effect of digestive juices and the first phase of metabolism. Condition of the patient.
In acute situations, in emergency medicine and intensive care
medicine, drugs are most often given intravenously. This is the most
reliable route, as in acutely ill patients the absorption of
substances from the tissues and from the digestive tract can often be
unpredictable due to altered blood flow or bowel motility.
Enteral routes are generally the most convenient for the patient, as
no punctures or sterile procedures are necessary. Enteral medications
are therefore often preferred in the treatment of chronic disease.
However, some drugs can not be used enterally because their absorption
in the digestive tract is low or unpredictable. Transdermal
administration is a comfortable alternative; there are, however, only
a few drug preparations that are suitable for transdermal
Desired target effect
Identical drugs can produce different results depending on the route
of administration. For example, some drugs are not significantly
absorbed into the bloodstream from the gastrointestinal tract and
their action after enteral administration is therefore different from
that after parenteral administration. This can be illustrated by the
action of naloxone (Narcan), an antagonist of opiates such as
A dummy wears a nebulizer mask, used to administer inhaled medications.
Inhaled medications can be absorbed quickly and act both locally and systemically. Proper technique with inhaler devices is necessary to achieve the correct dose. Some medications can have an unpleasant taste or irritate the mouth. Inhalation by smoking a substance is likely the most rapid way to deliver drugs to the brain, as the substance travels directly to the brain without being diluted in the systemic circulation. The severity of dependence on psychoactive drugs tends to increase with more rapid drug delivery. Parenteral
A peripheral IV placed on the hand.
A medical professional performs an intradermal (ID) injection.
The term injection encompasses intravenous (IV), intramuscular (IM),
subcutaneous (SC) and intradermal (ID) administration.
Parenteral administration generally acts more rapidly than topical or
enteral administration, with onset of action often occurring in
15–30 seconds for IV, 10–20 minutes for IM and 15–30 minutes for
SC. They also have essentially 100% bioavailability and can be
used for drugs that are poorly absorbed or ineffective when they are
given orally. Some medications, such as certain antipsychotics,
can be administered as long-acting intramuscular injections.
Ongoing IV infusions can be used to deliver continuous medication or
Disadvantages of injections include potential pain or discomfort for
the patient and the requirement of trained staff using aseptic
techniques for administration. However, in some cases, patients
are taught to self-inject, such as SC injection of insulin in patients
with insulin-dependent diabetes mellitus. As the drug is delivered to
the site of action extremely rapidly with IV injection, there is a
risk of overdose if the dose has been calculated incorrectly, and
there is an increased risk of side effects if the drug is administered
Neural drug delivery is the next step beyond the basic addition of
growth factors to nerve guidance conduits.
Drug delivery systems
^ TheFreeDictionary.com > route of administration Citing: Jonas:
Mosby's Dictionary of Complementary and Alternative Medicine. 2005,
^ Lees P, Cunningham FM, Elliott J (2004). "Principles of
pharmacodynamics and their applications in veterinary pharmacology".
J. Vet. Pharmacol. Ther. 27 (6): 397–414.
doi:10.1111/j.1365-2885.2004.00620.x. PMID 15601436.
^ a b c "topical".
The 10th US-Japan Symposium on Drug Delivery Systems FDA Center for Drug Evaluation and Research Data Standards Manual: Route of Administration. FDA Center for Drug Evaluation and Research Data Standards Manual: Dosage Form. A.S.P.E.N. American Society for Parenteral and Enteral Nutrition As Drug Administration Routes at the US National Library of Medicine Medical Subject Headings (MeSH)
v t e
Routes of administration, dosage forms
Digestive tract (enteral)
Pill Tablet Capsule Pastille Time release technology Osmotic delivery system (OROS)
Buccal (sublabial), sublingual
Orally disintegrating tablet
Mouthwash Toothpaste Ointment Oral spray
Ophthalmic, otologic, nasal
Ointment Suppository Enema
Murphy drip Nutrient enema
Injection, infusion (into tissue/blood)
Intracavernous Intravitreal Intra-articular injection Transscleral
Central nervous system
Intracerebral Intrathecal Epidural