Therapeutic drug can enter the body in various ways. Routes of administration of drugs are determined by the speed of the therapeutic effect, its severity and duration. In some cases, the way the drug enters the body determines the nature of its action, and hence our recovery. There are several main methods of oral administration of drugs, and each of them has its pros and cons. Before you figure out which route of administration to choose, you need to know exactly what forms of medicines exist.
Basic drug forms
Before determining the ways of introducing drugs into the body, you need to know what types of drugs exist, and there are many of them:
- Solutions are the liquid form of the drug. They are a medicinal substance diluted in water, alcohol, glycerin or other solvent. But it is worth remembering that high-quality andunspoiled solution should be clear, no cloudy sediment or foreign particles. They can be used for both parenteral and enteral administration.
- Decoctions and infusions - these products are prepared from plant materials. But it is worth remembering that they are not stored for a long time, no more than 3 days in a cool and protected from sunlight place.
- Tablets are a solid form of drugs that are obtained by pressing. They are mainly taken orally, but the external route of administration of drugs is also possible if they are crushed into powder.
- Dragee is another kind of solid form of drugs, they are created by layering the main substance on the granule. Used for oral administration.
- Capsules - a solid form of medicine, is a tablet coated with gelatin or other substance. Most often, capsules contain drugs with a bitter taste or a specific smell, thanks to the shell, the intake of these drugs is greatly facilitated. In addition, it allows you to protect the substance from rapid destruction in the digestive tract.
- Suppositories are a dosage form of a drug that remains solid at room temperature, but melts inside the human body. If we consider the introduction of drugs, the ways for candles are divided into two types - rectal and vaginal.
- A patch is a plastic form of a product that, under the influence of body temperature, softens and easily sticks toskin cover. Suitable for external use only.
- Ointments - a viscous consistency, used mainly for external use. They must contain about 25% solids in their composition.
There are several ways to administer drugs, let's take a closer look at each of them.
Types of enteral administration
The enteral route of drug administration is considered one of the most convenient and safe. There are several subtypes of this route: oral, sublingual, rectal.
1. Oral administration of the drug, in other words, ingestion, is one of the simplest methods, which is why it is most often prescribed by many doctors. The absorption of drugs received in this way occurs mainly by diffusion in the small intestine, in rare cases - in the stomach. The effect of the application is noticeable after 30-40 minutes. It is for this reason that this method is not suitable for emergency assistance. The rate and completeness of absorption depend on food intake, its composition and quantity. Thus, if you drink the medicine on an empty stomach, then the absorption of weak bases improves, since the acidity in the stomach is low, but the acids are better absorbed after eating. But there are also drugs, such as Calcium Chloride, which, when ingested after a meal, can form insoluble calcium s alts, which limits their ability to be absorbed into the blood.
2. Another convenient and effective enteral route of drug administrationfunds - sublingual. The medicine is placed under the tongue, thanks to the large network of capillaries in the mucous membrane, it is absorbed very quickly. The effect comes in a few minutes. This method of administration is most often used for the use of "Nitroglycerin" for angina pectoris, "Clonidine" and "Nifedipine" to eliminate a hypertensive crisis.
3. The rectal route is not used very often. It is mainly used if the patient has gastrointestinal diseases, or if he is unconscious.
Enteral administration: advantages and disadvantages
All ways and means of drug administration have their advantages, enteral also has them:
- Easy and easy to use.
- Natural.
- Relative safety for the patient.
- Does not require sterility, supervision by medical staff.
- Possibility of long-term therapy.
- Comfort for the patient.
But there are also disadvantages of the enteral route of drug administration:
- The effect comes slowly.
- Low bioavailability.
- Various suction speed and fullness.
- Influence of food intake and other components on the absorption process.
- Cannot be used by unconscious patients.
- It is undesirable to use by patients who have pathologies of the stomach and intestines.
Types of parenteral administration of drugs
The parenteral route of administration of drugs involves the administration of drugs without involving in this processdigestive system. It can be divided into several types.
In fabric:
- Intradermal - this method is mainly used for diagnostic purposes, such as Burne allergy tests or for local anesthesia.
- Subcutaneous - used if you want to get the maximum effect from the drug. This is achieved due to the fact that the subcutaneous fat layer is well supplied with blood vessels, and this contributes to rapid absorption.
- Intramuscular - used when subcutaneous injection causes irritation or pain, or when the drug itself is slowly absorbed.
Intraosseous - this method is used infrequently, mainly for extensive burns and deformities of the limbs, when other options fail
If drugs are to be administered, the paths through the vessels are as follows:
Intravenous - This method is used to administer a large number of drugs and some drugs that have such a requirement for use
- Intra-arterial - used in terminal conditions, which are caused by shock, large blood loss, asphyxia, electric shock, intoxication and infections.
- Into the lymphatic vessels - this method is used to ensure that the drug does not get into the liver and kidneys, to ensure more accurate delivery to the site of the disease.
Intravascular administration is not always convenientmedicines, paths can also lead through cavities:
- Pleural.
- Abdomen.
- Hearts.
- Articular.
Parenteral administration: pros and cons
Parenteral administration has a number of advantages:
- This method allows you to enter the drug bypassing the digestive tract, which is very important for patients with serious stomach pathologies.
- Speed of action needed in emergency situations.
- Maximum dosage accuracy.
- Entry of the drug into the blood in unchanged form.
The parenteral route of drug administration has a number of disadvantages:
- The drug must be administered by a trained medical professional.
- Asepsis and antisepsis required.
- Difficult and even impossible drug administration in case of bleeding, damage to the skin at the injection site.
Inhalations
The inhalation route of drug administration allows the use of aerosols, gases (volatile antiseptics) and powders (sodium chromoglycate) in the treatment. With this method of administration, the drugs quickly get inside and exert their therapeutic effect. In addition, the concentration of the agent in the blood is easily controlled - the cessation of inhalation leads to a suspension of the action of the drug. With the help of inhalation of an aerosol, the concentration of the agent in the bronchi is very high with a minimal systemic effect.
But it is worth remembering that no matter howinhalation has not been effective, it does not allow the use of irritating substances. You also need to keep in mind that inhaled drugs can affect others (for example, anesthesia).
Pros and cons of inhalation administration
We continue to consider the ways of drug administration. The inhalation method also has advantages and disadvantages. Pros of inhalation:
- Acts directly at the very site of the pathology.
- The drug easily penetrates to the site of inflammation, while bypassing the liver unchanged, which causes its high concentration in the blood.
Cons of inhalation:
- If the bronchial patency is severely impaired, then the drug does not penetrate well into the focus of the disease.
- Drugs can irritate the nose, mouth and throat.
The main routes of drug administration have been considered, but there are others that may also become indispensable in some cases.
Rectal, vaginal and urethral routes of administration
If we compare the rectal route of drug administration with oral administration, we can say for sure that the effect of the first method comes much faster. The drug is quickly absorbed into the bloodstream without being destroyed by the action of digestive tract and liver enzymes.
Suppositories, ointments, and other forms of preparations, previously ground into powder and diluted, are administered rectally into the body, while enemas are used. But it is worth remembering that the solution administered rectallywill give effect much faster than a candle. The volume of an enema for adults is 50 to 100 ml, and for children it is 10 to 30 ml. But this method of drug administration also has disadvantages:
- Inconvenient application.
- Special fluctuations in speed and complete suction pattern.
That is why the rectal route of administration is recommended to be used only in cases where oral administration is difficult, when it is necessary that the drug quickly enters the bloodstream, and injections are contraindicated for one reason or another.
Vaginal and urethral methods allow you to enter any form of drugs. But both of these methods give the best result if they are used to treat infections in these organs or for diagnostics, for example, for the introduction of contrast agents such as Iodamide, Triombrust and others.
Spinal and intracranial routes of administration
In very rare cases, spinal and intracranial (suboccipital, subarachnoid, subdural and others) injections are used. This is due to a greater extent to the fact that only a qualified specialist should administer the drug by such methods. Such methods require the use of only sterile, completely transparent, true aqueous solutions with a neutral reaction. The action comes very quickly.
Transdermal therapeutic systems
Recently, more and more drugs appear in a new form. Transdermal therapeutic systems (TTS) is one of them. They are soft dosage form,intended for external use with a slow release of the drug. Modern TTS are films and patches that were made using cutting-edge technologies and are very convenient to use: the patch is glued to the skin, and the film is placed behind the cheek. In this case, the main substance is absorbed into the blood through the skin or mucous membranes.
Many physicians around the world have recently been paying more and more attention to the latest ways of administering drugs. Everyone has advantages and disadvantages, including TTS. Consider the pros:
- The drug works at an accelerated rate.
- The drug enters the bloodstream gradually without interruption, which ensures a stable level of the main substance.
- Unpleasant sensations are completely excluded, this also applies to vomiting and pain from injections.
- Complete absence of undesirable effects from the digestive tract.
- Reduce the incidence of allergies.
- Possibility of quick discontinuation of the drug, if suddenly there are contraindications.
- Accurate dosage.
- Possibility of targeted drug delivery to the desired part of the body.
Each of the described routes of drug administration has its pros and cons. But no matter how good the method, the main thing is that it should be prescribed by a doctor, and it is desirable that the most complex and rare methods of administration be carried out by a specially trained person in a medical institution. Take care not toI had to think about how to deliver the medicine into the body.
