In pharmacology and 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. It has been suggested that Drug development be merged into this article or section. ... Toxicology (from the Greek words toxicon and logos) is the study of the adverse effects of chemicals on living organisms. ... Drug may refer to: A substance perceived or defined as a drug in clinical medical practice or a substance perceived or defined as a drug in legislation and political strategies so as to prevent or punish abuse of the substance. ...

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 pharmacokinetic properties of a drug (that is, those related to processes of uptake, distribution, and elimination) are critically influenced by the route of administration. Pharmacokinetics is a branch of pharmacology dedicated to the study of the time course of substances and their relationship with an organism or system. ...

Classification

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 following is a list of some routes of administration. For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and...

Topical

• epicutaneous (application onto the skin), e.g. allergy testing, topical local anesthesia
• inhalational, e.g. asthma medications
• enema, e.g. contrast media for imaging of the bowel
• eye drops (onto the conjunctiva), e.g. antibiotics for conjuncitivitis
• ear drops - such as antibiotics and corticosteroids for otitis externa
• intranasal, e.g. decongestant nasal sprays
• sublingual: e.g. nitroglycerine: the medication is taken up directly by the tongue's vascular supply

Local anesthesia is any technique to render part of the body insensitive to pain without affecting consciousness. ... This 2qt (about 2 liters) enema bag, or fountain syringe, equipped with a rectal nozzle, is to be filled with water or a solution, then suspended near the patient using the hook. ... The conjunctiva is a membrane that covers the sclera (white part of the eye) and lines the inside of the eyelids. ... An antibiotic is a drug that kills or slows the growth of bacteria. ... In physiology, corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. ... A decongestant is a broad class of drugs designed to symptomatically treat ailments affecting the respiratory system. ... Sublingual, literally under the tounge, refers to a route of administration for some drugs (see buprenorphine, ecstacy, Lorazepam). ... Nitroglycerin (also nitroglycerine, trinitroglycerin, or glyceryl trinitrate) is a chemical compound, a heavy, colorless, poisonous, oily, explosive liquid obtained by nitrating glycerol. ...

Enteral

• by mouth (orally), many drugs as tablets, capsules, or drops
• by gastric feeding tube, duodenal feeding tube, or gastrostomy, many drugs and enteral nutrition
• rectally, various drugs in suppository or enema form

Sagittal section of nose mouth, pharynx, and larynx. ... Common disk-shaped pills A pharmacological tablet is a medicinal or other active substance mixed with binder powders and pressed into a tablet form. ... A nasogastric tube (NG tube) is a plastic tube, inserted into a nostril through the nose, into the throat, down the oesophagus and into the stomach. ... In anatomy of the digestive system, the duodenum is a hollow jointed tube that connects the stomach to the jejunum. ... Gastrostomy refers to a surgical opening into the stomach. ... ... The posterior aspect of the rectum exposed by removing the lower part of the sacrum and the coccyx. ... 4 500mg acetaminophen/paracetamol suppositories A suppository is a medicine that is inserted either into the rectum (rectal suppository) or into the vagina (vaginal suppository) where it melts. ... This 2qt (about 2 liters) enema bag, or fountain syringe, equipped with a rectal nozzle, is to be filled with water or a solution, then suspended near the patient using the hook. ...

Parenteral by injection or infusion

• intravenous (into a vein), e.g. many drugs, total parenteral nutrition
• intraarterial (into an artery), e.g. vasodilator drugs in the treatment of vasospasm and thrombolytic drugs for treatment of embolism
• intramuscular (into a muscle), e.g. many vaccines, antibiotics, and long-term psychoactive agents.
• intracardiac
• subcutaneous (under the skin), e.g. insulin
• 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 paediatrics when intravenous access is difficult
• intradermal, (into the skin itself) is used for skin testing some 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.

Injection has multiple meanings: In mathematics, the term injection refers to an injective function. ... An infusion pump or perfusor infuses fluids, medication or nutrients into a patients circulatory system. ... An intravenous drip in a hospital Intravenous therapy or IV therapy is the administration of liquid substances directly into a vein. ... In biology, a vein is a blood vessel which returns blood from the microvasculature to the heart. ... Total parenteral nutrition (TPN), also called hyperalimentation, is the practice of feeding a person without using the gut, i. ... Section of an artery An artery or arterial is also a class of highway. ... A vasodilator is a substance that causes blood vessels in the body to become wider by relaxing the smooth muscle in the vessel wall. ... Vasospasm refers to a condition in which blood vessels spasm, leading to constriction. ... Thrombolytic drugs are used in medicine to dissolve blood clots in a procedure termed thrombolysis. ... In medicine, an embolism occurs when an object (the embolus, plural emboli) migrates from one part of the body (through the circulation) and cause(s) a blockage (occlusion) of a blood vessel in another part of the body. ... Intramuscular injection is an injection of a substance directly into a muscle. ... A top-down view of skeletal muscle Muscle is a contractile form of tissue. ... A vaccine is an antigenic preparation used to produce active immunity to a disease, in order to prevent or ameliorate the effects of infection by any natural or wild strain of the organism. ... The subcutis is the layer of tissue directly underlying the cutis. ... The structure of insulin Red: carbon; green: oxygen; blue: nitrogen; pink: sulfur. ... Intraosseous infusion is the process of injection directly into the bone marrow of the bone. ... Grays illustration of a human femur, a typically recognized bone. ... An allergen is any substance (antigen), most often eaten or inhaled, that is recognized by the immune system and causes an allergic reaction. ... A Tattoo is a design in ink or some other pigment, usually decorative or symbolic, placed permanently under the skin. ... In higher vertebrates, the peritoneum is the serous membrane that forms the lining of the abdominal cavity - it covers most of the intra-abdominal organs. ...

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. cocaine snorting, sublingual nitroglycerine
• inhalational, e.g. inhalational anesthetics

A transdermal patch is a medicated adhesive patch that is placed on the skin to deliver a time released dose of medication through the skin and into the bloodstream. ... This article is about the drug Cocaine. ... Nitroglycerin (also nitroglycerine, trinitroglycerin, or glyceryl trinitrate) is a chemical compound, a heavy, colorless, poisonous, oily, explosive liquid obtained by nitrating glycerol. ... Inhalational anaesthetics are gases or vapours possessing anaesthetic qualities. ...

Other

• 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

In higher vertebrates, the peritoneum is the serous membrane that forms the lining of the abdominal cavity - it covers most of the intra-abdominal organs. ... In medicine, renal dialysis is a method for removing waste such as urea from the blood when the kidneys are incapable of this (i. ... The epidural space is a part of the human spine which is very close to the spinal cord, lying just outside the dura mater. ... Cerebrospinal fluid (CSF) is a clear bodily fluid that occupies the subarachnoid space in the brain (the space between the skull and the cerebral cortex—more specifically, between the arachnoid and pia layers of the meninges). ... Spinal anaesthesia is a form of local, or more specifically regional, anaesthesia involving injection of a local anaesthetic into the cerebrospinal fluid (CSF), generally through a long fine needle. ...

Uses

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 anesthetics is targeted at the brain (systemic effect). A general anaesthetic drug is an anaesthetic (or anesthetic AE) drug that brings about a reversible loss of consciousness. ...

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 opiates such as morphine. Naloxone counteracts opiate action in the central nervous system when 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. Naloxone is a drug used to counter the effects of overdosing on opioids such as heroin and morphine. ... The term opiate refers to the alkaloids found in opium, an extract from the seed pods of the opium poppy (). It has also traditionally referred to natural and semi-synthetic derivatives of morphine. ... Morphine (INN), the principal active agent in opium, is a powerful opioid analgesic drug. ... A diagram showing the CNS. The central nervous system (CNS) represents the largest part of the nervous system. ...

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 few drug preparations suitable for transdermal administration. Sterility is the quality or state of being unable to reproduce. ...

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. Emergency medicine is a branch of medicine that is practiced in a hospital emergency department, in the field (in a modified form; see EMS), and other locations where initial medical treatment of illness takes place. ... Intensive care medicine or critical care medicine is concerned with providing greater than ordinary medical care and observation to people in a critical or unstable condition. ...

Notes

Note 1: In toxicology, "exposition" may often be a more appropriate term, however "administration" can be used for deliberate substance use.

See also

• Medical injection
• Catheter
• Intravenous therapy
• Hypodermic needle