Pharmacology is a science that studies the effect of drugs on the human body, methods for obtaining new drugs. Even in ancient Greece and India, in the tundra and on the southernmost edge of Africa, people tried to find a way to fight the disease. It became, in a sense, their obsession, a dream worth striving for.
Pharmacological terminology
Medications are substances or combinations thereof that are used to treat a disease or as a preventive measure.
A medicinal product is a medicinal product that is already ready for use.
There are different forms of drugs. This is done for ease of use and the possibility of an individual approach to the treatment of patients. In addition, due to the variety of forms of release, it is possible to deliver the drug to the body in several ways. This makes it easier to work with unconscious patients, as well as people who have received injuries and burns.
List A and B
All drugs are divided into three groups:
- list A (poisons);
- list B (strong drugs, including analgesics);
-medicines available without a prescription.
Class A and B drugs require increased attention, so a special prescription is required to obtain them in the pharmacy chain. In addition, you need to know where and how to properly store these medicines. Since they may well decompose in sunlight or acquire additional toxic properties. And some drugs, such as morphine, are subject to strict accountability. Therefore, each ampoule is handed over by nurses at the end of the work shift with an entry in the appropriate journal. Some other medicines are also registered: antipsychotics, narcosis drugs, vaccines.
Recipes
A prescription is a written request from a doctor to a pharmacist or pharmacist with a request to sell a medicine to a patient, indicating the form, dose and method and frequency of use. The form immediately performs the functions of a medical, legal and monetary document if the medicines are given to the patient on a preferential basis or without payment.
There is a legislative act that regulates the rules for issuing prescriptions for doctors of various speci alties and positions.
A drug is not only a substance that can eliminate a disease or its manifestations, but also a poison, so the doctor must correctly indicate the dosage when issuing a prescription.
Doses
On the prescription form, the amount of the medicinal substance is written in Arabic numerals in mass or volume units of the decimal system. Whole grams are separated by a comma,for example, 1, 0. If the medicine contains drops, then their number is indicated by Roman numerals. Some antibiotics are calculated in international units (IU) or biological units (U).
Medications are substances that can be in solid, liquid or gaseous form. Liquids and gases in prescriptions are indicated in milliliters, in the case of inhalation, the doctor can only note the dose of dry medicine.
At the end of the prescription is the signature and personal seal of the doctor. In addition, the patient's passport data is indicated, such as surname, initials, age. Be sure to include the date of issue of the prescription and its expiration date. There are special forms for recording prescriptions for subsidized drugs, narcotics, sleeping pills, antipsychotics, and painkillers. They are signed not only by the attending physician, but also by the head physician of the hospital, certifies with his seal, and puts a round seal of the medical institution on top.
It is forbidden to prescribe ether for anesthesia, fentanyl, chloroethane, ketamine and other sleeping substances in the outpatient clinic. In most countries, prescriptions are written in Latin, and only recommendations for admission are written in a language that the patient understands. For narcotic and poisonous substances, the validity of the marketing authorization is limited to five days, for medical alcohol - ten, the rest can be bought within two months from the date of issuance of the prescription.
General classification
In modern realities, when there are the most unusual medicinalmeans, classification is simply necessary in order to navigate in their diversity. For this, several conditional guides are used:
- Therapeutic use - groups of medicines are formed that are used to treat one disease.
- Pharmacological action - the effect that the drug produces in the body.
- Chemical structure.
- Nosological principle. It is similar to therapy, only the distinction is even narrower.
Classification by groups
At the dawn of the development of medicine, doctors tried to systematize medicines themselves. Classification as such appeared through the efforts of chemists and pharmacists, compiled according to the principle of the application point. It included the following categories:
1. Psychotropic drugs and agents acting on the central nervous system (tranquilizers, antipsychotics, sedatives, antidepressants, antiepileptics, anti-inflammatory drugs).
2. Drugs acting on the peripheral nervous system (ganglioblockers, anticholinergics)
3. Local anesthetics.
4. Drugs that change vascular tone.
5. Diuretics and cholagogues.
6. Drugs that affect the organs of internal secretion and metabolism.
7. Antibiotics and antiseptics.
8. Anticancer drugs.
9. Means for diagnostics (dyes, contrast agents, radionuclides).
This and similar division helps young doctors to better understand what they already havemedicines. Classification into groups helps to intuitively understand the mechanism of action of a particular drug and remember dosages.
Classification by chemical structure
This feature is most suitable for the classification of antiseptic and antimicrobial drugs. There are bactericidal and bacteriostatic drugs. The chemical structure classification covers both of these groups. The chemical structure of a substance reflects the mechanism of action of the drug and its name.
- Halides. They are based on a chemical element of the halogen group: chlorine, fluorine, bromine, iodine. For example, antiformin, chloramine, pantocid, iodoform and others.
- Oxidizers. It is easy to guess that their mechanism of action is aimed at the formation of a large amount of free oxygen. These include hydrogen peroxide, hydroperite, potassium permanganate crystals.
- Acids. They are used in medicine in large quantities. The most famous of them are salicylic and boric.
- Alkalis: sodium borate, bicarmint, ammonia.
- Aldehydes. The mechanism of action is based on the ability to remove water from tissues, making them more rigid. Representatives - formalin, formidron, lysoform, urotropin, urosal, ethyl alcohol.
- Heavy metal s alts: sublimate, mercury ointment, calomel, lapis, collargol, copper sulfate, lead plaster, zinc oxide, Lassar paste, etc.
- Phenols. They have an irritating and cauterizing effect. The most common of them are carbolic acid, lysol.
- Dyes. Used in diagnosticmanipulations and as a local irritant and antibacterial agent. These include methylene blue, brilliant green, fucorcin.
- Tars and resins, for example, Vishnevsky's balm, Wilkinson's ointment, ichthyol, paraffin, naphthalene, sulsen. Improve local blood supply to tissues.
Solid drugs
These drugs have the following representatives: tablets, dragees, powders, capsules and granules and other medicines. Determining the release form is not difficult, since you can determine with the naked eye what exactly is in front of you.
Pills are obtained by shaping the powder, consisting of the active substance and the excipient. This is usually done under pressure.
Dragee is an active and auxiliary substance arranged in layers, pressed around a granule.
Powders have several uses. They can be drunk, sprinkled on wounds, diluted with saline and injected intramuscularly or intravenously. There are undosed and dosed powders, which, in turn, are simple and complex.
Capsules are gelatin shells that contain liquid, granular, powder or paste medicine.
Granules are most often found in homeopathic preparations, they look like small particles (less than half a millimeter in size).
Liquid Forms
To this cooking methodpreparations include solutions, galenic and novogalenic preparations, balms, collodions and other liquid and semi-liquid options.
Solutions are formed by mixing a drug and a solvent such as water or alcohol.
Herbal preparations consist only of herbal extracts obtained by heating.
Infusions and decoctions are prepared from dry plants. They each sign the prescription, including the amount of diluent the pharmacist should use.
Infusion and extract - on the contrary, alcohol-containing liquids. They can be either pure or alcoholic or ethereal. Novogalenic preparations differ from conventional, galenic, high degree of purification of raw materials and the finished product.
Special Forms of Medicines
Balsams are oily liquids with deodorizing and antiseptic properties. Collodion is a solution of nitrocellulose with alcohol and ether in a combination of one to six. They are used exclusively externally. Creams have a semi-liquid consistency and contain plant extracts mixed with a base such as glycerin, wax, paraffin, etc. Lemonades and syrups are designed to make it easier for children to take medicines. This helps to interest the little patient in the treatment process without additional effort.
Sterile aqueous and oily solutions are suitable for injection. They can be as simple as they are complex. When writing a prescription, always indicate the dose of the substance and the volumein one ampoule, as well as recommendations on where exactly the drug should be injected.
Soft shapes
If fatty or fat-like substances are used as a base, soft medicines are obtained. The definition, classification, manufacturing process of these - all these issues are perfectly studied by chemists and pharmacists, while the doctor only needs to know the dose and indications for the appointment.
So, ointments must contain at least twenty-five percent dry matter. Appropriate consistency can be achieved by mixing the powders with animal fat, wax, vegetable oils, petroleum jelly or polyethylene glycol. The same criteria apply to pastes, but they must be more viscous. Liniments, on the contrary, should be more liquid, and before use they need to be shaken so that the settled powder is evenly distributed inside the solvent. Candles or suppositories have a solid form, but when ingested, they quickly melt and become liquid. The patches are also solid at room temperature, but on the skin they melt and stick to form a firm contact.
Medications are substances predominantly of plant origin that have been chemically or physically processed to make them better absorbed by the patient's body.
