Route of administration
In pharmacologyand toxicology, a route of administration is the path by which a drug, fluid, poison or other substance is brought into contact with the body 1.
Obviously, a substance must be transported from the site of entry to the part of the body where its action is desired to take place (unless this is on the body surface). However, using the body's transport mechanisms for this purpose can be far from trivial. The pharmacokineticproperties of a drug (that is, those related to processes of uptake, distribution, and elimination) are critically influenced by the route of administration.
- 1 Classification
- 1.1 Topical
- 1.2 Enteral
- 1.3 Parenteral by injection or infusion
- 1.4 Parenteral (other than injection or infusion)
- 1.5 Other
- 2 Uses
- 3 Notes
- 4 See also
- 5 External links
Routes of administration can broadly be divided into:
- topical: local effect, substance is applied directly where its action is desired
- enteral: desired effect is systemic (non-local), substance is given via the digestive tract
- parenteral: desired effect is systemic, substance is given by other routes than the digestive tract
The U.S. Food and Drug Administrationrecognizes 111 distinct routes of administration. The following is a brief list of some routes of administration.
- epicutaneous (application onto the skin), e.g. allergy testing, topical local anesthesia
- inhalational, e.g. asthmamedications
- enema, e.g. contrast media for imaging of the bowel
- eye drops (onto the conjunctiva), e.g. antibioticsfor conjuncitivitis
- ear drops - such as antibiotics and corticosteroidsfor otitis externa
- intranasal, e.g. decongestantnasal sprays
- sublingual: e.g. nitroglycerine: the medication is taken up directly by the tongue's vascular supply
- by mouth(orally), many drugs as tablets, capsules, or drops
- by gastric feeding tube, duodenalfeeding tube, or gastrostomy, many drugs and enteral nutrition
- rectally, various drugs in suppositoryor enemaform
Parenteral by injectionor infusion
- intravenous(into a vein), e.g. many drugs, total parenteral nutrition
- intraarterial (into an artery), e.g. vasodilatordrugs in the treatment of vasospasmand thrombolytic drugsfor treatment of embolism
- intramuscular(into a muscle), e.g. many vaccines, antibiotics, and long-term psychoactive agents.
- subcutaneous(under the skin), e.g. insulin
- intraosseous infusion(into the bonemarrow) 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
- intradermal, (into the skin itself) is used for skin testingsome allergens, and also for tattoos
- intraperitoneal, (into the peritoneum) is predominantly used in veterinary medicine and animal testing for the administration of systemic drugs and fluids due to the ease of administration compared with other parenteral methods.
Parenteral (other than injection or infusion)
- transdermal(diffusion through the intact skin), e.g. transdermal opioid patches in pain therapy
- transmucosal (diffusion through a mucous membrane), e.g. cocainesnorting, sublingual nitroglycerine
- inhalational, e.g. inhalational anesthetics
- intraperitoneal (infusion or injection into the peritoneal cavity), e.g. peritoneal dialysis
- epidural (synonym: peridural) (injection or infusion into the epidural space), e.g. epidural anesthesia
- intrathecal (injection or infusion into the cerebrospinal fluid), e.g. antibiotics, spinal anesthesia
Some routes can be used for topical as well as systemic purposes, depending on the circumstances. For example, inhalation of asthma drugs is targeted at the airways (topical effect), whereas inhalation of volatile anestheticsis targeted at the brain (systemic effect).
On the other hand, 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, an antagonist of opiatessuch as morphine. Naloxone counteracts opiate action in the central nervous systemwhen given intravenously and is therefore used in the treatment of opiate overdose. The same drug, when swallowed, acts exclusively on the bowels; it is here used to treat constipation under opiate pain therapy and does not affect the pain-reducing effect of the opiate.
Enteral routes are generally the most convenient for the patient, as no punctures or sterileprocedures 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 few drug preparations suitable for transdermal administration.
In acute situations, in emergency medicineand 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.
Note 1: In toxicology, "exposition" may often be a more appropriate term, however "administration" can be used for deliberate substance use.
- Medical injection
- Intravenous therapy
- Hypodermic needle
- 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.es:Vía de administración
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It uses material from the http://en.wikipedia.org/wiki/Route+of+administration Wikipedia article Route of administration.