There are many different ways to introduce a drug into the human body. At the dawn of medicine, local methods were first used in the form of applications, rubbing, compresses and oral, including the ingestion of a number of dosage forms or sublingual resorption. With the development of medicine and technology for delivering the active substance to the target organ, more complex methods began to be used.
Rectal and vaginal suppositories (candles), multi-component tablets and capsules, including those coated with a shell that dissolves either with gastric juice or intestinal enzymes, appeared. Injection methods: intra- and subcutaneous, intramuscular, intravenous and intra-arterial, intraosseous. The drugs are injected into the joints and into the cavities of the organs.
Despite the rather simple route of administration, endotracheal and intranasal preparations have been used relatively recently. Certainly,nose drops already existed under Hippocrates. However, intranasal is as one of the ways to administer the drug for delivery to other organs, and not a remedy for edema in the common cold, and such an administration began to be used only a few decades ago.
Groups of intranasal drugs with a general (systemic) effect
Multiple studies have shown that the fight against a runny nose is not the only reason for the introduction of a drug into the nasal cavity. A number of drugs that have a systemic effect are completely absorbed from the mucous membrane of the nasal passages and reach their immediate destination.
Intranasal administration possible for:
- H1-antihistamine (antiallergic);
- a-agonists (vasoconstrictor);
- mast cell membrane stabilizers;
- serotonergic (having various effects - from vasoconstriction to antiallergic);
- hormonal and antihormonal;
- narcotic analgesics;
- immunomodulators;
- correctors of cartilage and bone tissue metabolism;
- psychostimulants and nootropics.
Features of intranasal administration of drugs
For quite a long time, pharmaceutical companies have been trying to solve two unsolvable problems regarding the use of drugs that have a protein chemical structure. The stumbling block was the destruction of the protein-peptide component of the active substance by gastric juice andintestinal enzymes when taken orally. Another problem was the phenomenon of the first pass through the liver - the binding of the active complex and its excretion.
The solution was found in the use of injectables and rectal suppositories. However, the first path is characterized by some technical complexity, combined with unpleasant sensations. And the second one turned out to be insufficiently effective due to low absorption in the final sections of the rectum. The decision came unexpectedly. It turned out that intranasal is, like injectable, such an introduction, which achieves a rapid onset of a therapeutic effect. And with the addition of certain concomitant substances, the same high bioavailability is ensured, that is, the required concentration of the active ingredient at the site of its application.
Another useful property of intranasal administration was manifested in extracellular (bypassing absorption into the blood through the mucous membrane) penetration of active substances into the brain. Getting to the olfactory zones, the drug is delivered through the fibers of the olfactory and trigeminal nerves.
Forms of intranasal preparations
For introduction into the nasal cavity, a fairly limited number of pharmacological forms are used. First of all, it is, of course, nose drops. It is possible to inhale powders with a fine structure. Used laying ointments. Various solutions or decoctions of herbs for washing the nasal cavities do not belong to this group due to the short exposure tomucous when applied.
The main form of intranasal drugs with a systemic effect are nasal sprays. They are available in the form of compressed air dispensers or with an active spray pump. Thanks to a certain volume of spray ejection with a single press, there is the possibility of a relatively controlled dosage of the drug.
Also, when using the spray, there is a uniform irrigation of the nasal mucosa. This contributes to a more complete absorption of the drug, which increases its pharmacological action.
Main benefits of intranasal administration
Based on the above, it is possible to determine the key advantages that intranasal preparations have. The ease and simplicity of administration, which does not require additional technical equipment and special training, as in the case of injection methods, are quite significant from the side of their use by the patient.
From the standpoint of physiology and pharmacology, the possibility of a central action on brain structures comes first. A pronounced systemic effect, occurring in a short time, as with the injection method of administration, is also of great importance. Due to the absence of the phenomenon of the first pass through the liver, high bioavailability of the drug and a small number of associated adverse reactions are ensured.
Disadvantages of the method
From the point of view of the systemeffect, the main problem is to maintain the level of therapeutic concentration of the drug in the blood plasma. The agent is rapidly absorbed and reaches peak action in a short time, so intranasal administration can only be used for short-term correction of conditions. A prolonged effect is possible only with the introduction of drugs that have an effect on brain structures.
In addition, the development of local reactions on the nasal mucosa is possible. This is due to the rather high concentration of the active ingredient in the spray and the content of additional components that ensure the maximum passage of the drug from the surface of the mucous membrane into the blood.
The possibility of absorption from the nasal cavity has a fairly limited number of drugs that have the necessary physical and chemical properties for this. In the patient, an increased concentration of the active substance leads to significant costs for the purchase of a spray.
Intranasal immunomodulators
During the off-season or during epidemics of colds, drugs that increase the general and local immune defenses of the body are widely used for the prevention and treatment.
Intranasal interferon is used for emergency prevention and protection.
With multiple studies, it turned out that the intranasal route of administration of immunomodulators contributes not only to preventing the penetration of pathogenic viruses through the nasal mucosa. It also stimulates the work of its own protective forces - the activationproduction of their own interferons. To stimulate the production of endogenous interferon as a means of maintenance therapy, the drug "Anandin" intranasal is used.
Human Interferon
A drug of specific immune protection, having activity against most pathogens of viral colds, "Interferon" is available in the form of tablets, injectables and powders for the preparation of drops. For prevention and treatment, you can use any form of release. But to provide local protection, intranasal is preferable. This, like an invisible barrier, will prevent the penetration of a significant amount of viruses into the cells of the nasal mucosa. This will ensure a lower incidence in an epidemic.
Immunostimulator "Anandin", eye and intranasal drops
The drug is widely used due to the almost complete absence of side effects, adverse reactions and a good immunostimulating effect. In addition to this, it also has a pronounced wound healing property, which is important when used in the form of eye drops for corneal or conjunctival trauma.
Contraindications for use are only administered intramuscularly "Anandin". Intranasal drops are allowed at any age, during pregnancy, lactation and other physiological conditions or diseases.
If allergic runny nose
Often causing itchy nose, sneezing and copious dischargemucus becomes not a virus, but an antigen, leading to a nonspecific immune reaction - allergies. In the complex treatment of this form of rhinitis, intranasal corticosteroids are often used. This is especially true for people suffering from seasonal forms of allergies - hay fever.
During the flowering period of certain plants, it is not enough for such patients to use only antihistamines, which in most cases also have a sedative effect. This is unacceptable when driving vehicles, working with mechanisms or in conditions of maximum mental concentration. Then local hormonal sprays are prescribed, which relieve the manifestation of symptoms without significantly affecting the overall hormonal background.
Precautions
Despite the wide availability and easy tolerance of such drugs, it is important to remember that intranasal is, like any other, a drug that should be used exclusively as directed by a doctor, in the prescribed dosage, frequency and duration of administration.
Often there are situations when you need to take several drugs at once, none of which can be canceled. Therefore, it will be necessary to find out whether they will have a negative effect on the body when combined. Instructions for use cannot include all options for the development of an allergic reaction. That is why before taking such common drugs as suppositories, ointments and sprays, you should definitely consult withspecialist.
