The toxic action of drugs on the human body

Pharmacological composition of the most effective drugs is not complete without the presence of chemicals. In this regard, many drugs are able not only to cure but also to cause side effects. The toxic effect is uncharacteristic response of organism to any stimuli. Various unexpected symptoms may be the result of lesions of organs, tissues and various systems of the body.


The manifestation of complications of medication, can be the following reasons:

  • physico-chemical composition of the drug;
  • senile or age of the host;
  • the formation of decomposition products, toxic substances, poisons the body;
  • weak General condition of the patient;
  • excess dosage or the wrong drug;
  • combining incompatible pharmacological properties of drugs;
  • individual intolerance of one of the components of the drug, dysbiosis or allergies;
  • the take prohibited medications during pregnancy and lactation.

The toxic effects of drugs, as a rule, is distributed selectively, acting on the individual organs and tissues of the body. However, its acute phase can trigger the start of irreversible processes in multiple systems simultaneously.

Mechanism of action

Almost every medicinal substance (LV) causes side effects, not all of them manifest themselves. Reactions disappear after discontinuation of the drug. However, for the patient there is a risk of "drug disease".

Two main aspects that help to avoid serious consequences, is the adherence, and following the instructions to the drug.

The mechanism of toxic action such that the time range from the time of taking the medication before the manifestation of side effects has no clear boundaries. They can identify yourself immediately after taking medicine and after a few weeks, months and even years. Acute toxic effect manifests itself sharply and promptly. Most often affected is the liver and kidneys of the patient, as these organs are involved in filtration and excretion of waste products toxins and harmful substances. Excessive stress can lead to complete dysfunction.

Fetotoxic effects

During the gestational period energy and resources the parent organism fully focused on the development of the fetus. Though a pregnant woman and the embryo different the blood supply of the nutrition it receives through the umbilical cord and all substances that go inside the mother's body are transported to the child. Such a thing as fetotoxic effects, involves abnormal development of the fetus as a result of taking prohibited during pregnancy medications and occurs in the first trimester.

Prior to the attachment of the ovum to the placenta (the first 1-3 weeks after fertilization) of the drug affect its development in the lumen of the fallopian tube and it moves into the uterus. Such action is threatened by the emergence of various deformities in the newborn. Among the meds, which can largely affect the embryo, are antimetabolites and antimycotic remedies: colchicine, fluorouracil, mercaptopurine.

Teratogenic effects

Since the beginning of the second month of pregnancy until its end is teratogenic effects. It was at the end of the eight-week period from the beginning of gestation the fetus develops the skeleton and internal organs are laid. His tissue on this point is very sensitive to external negative factors. Congenital deformities in the form of abnormal skeletal development or failure of organs is a consequence of teratogenic drugs who took the mother during pregnancy.

It was revealed that after taking strong sleeping pills and anxiolytic drugs, such as thalidomide, the child was born with improperly developed limbs, having the form of fins. Teratogenic toxic effects may also have antitumor drugs and alcohol received in the female body during conception.

Fetotoksičeskoe effect

When the pregnancy reaches 20 weeks, at this stage, all systems and organs are already formed and functioning in the same way as an adult. During this period, as a result of the medication on the unborn child is affected fetotoksičeskoe effect. Anticoagulants affect the blood, inhibiting the function of blood clotting. Strong sleeping pills and sedatives affect the Central nervous system. The use of ethanol, even in the composition of drugs, in small quantities and the drugs also cause a reaction in the Central nervous system can lead to the development of cerebral palsy.

Mutagenic effect

Medicinal substances are able to exert a mutagenic effect, manifested by a change in the genetic information in the germ cells of both sexes and the stage of cell formation of the embryo.

Carcinogenic effects

Carcinogenicity is the ability of the drug to cause host cell destruction and the absorption of the neighbouring tissues, which leads to the formation of malignant tumors.


Given thattoxic effect of LP can cause irreparable harm, the appointment of any drug to a pregnant woman must be an obstetrician-gynecologist. This does not mean that the situation is not to take anything. In order to avoid severe consequences, you should carefully study the user manual and the product and to adequately assess the benefit ratio for the mother/risk for fetus.

Mild sedative herbs, vitamins and folic acid can be taken during this period. However, medication should be under close medical supervision. An important aspect is tracking the status of the mother and development of fetus in the blood and urine tests.

Modern pharmacology introduces only those LV, which is not able to exert embryotoxic, teratogenic, fetotoksicheskoe, mutagenic and carcinogenic effects on the human body and the baby inside the mother's womb.

Allergies and dysbiosis


Breach of the natural microflora is also a symptom of toxic action. Dysbacteriosis (dysbiosis) is the lack of beneficial bacteria in the gut, mouth and vagina, and which is replaced by pathogenic fungal organisms. This phenomenon is the consequence of taking antibiotics and some hormones.

Toxic effects due to dysbiosis manifested in the following reactions:

  • gastrointestinal: frequent diarrhea, cramping and abdominal pain, bloating and flatulence;
  • on the part of the female reproductive system: vaginal candidiasis, the distinctive symptoms are itching and a white cheesy discharge from the vagina;
  • in case of violation of the microflora of the oral cavity: stomatitis, sores and wounds on the gums and the sky, thrush in the tongue, increased body temperature, unpleasant smell.

To prevent such reactions antibiotics combined with antifungals (nystatin, pimafucin) probiotics and prebiotics (bifidumbakterin, lacidofil, etc.).


Allergic reactions due to toxic effects occur on the background of the perception of LV components as antigens. The dosage in this case is not important and severity of side effects vary: it can be skin rashes, and anaphylaxis.

There are four types of allergic reactions:

  1. Immediate. Develops within several hours after ingestion of toxic drugs. The dosage may be minimal. E immunoglobulins react with antigens that leads to the release of histamine. Manifestations of toxic effects can be itching, swelling, rash, runny nose, itchy eyes, throat swelling and anaphylaxis. To provoke an immediate response can antibiotics of the penicillin series.
  2. Cytotoxic. Non-specific reactions of the cells caused by production of antibodies IgG and IgM to determinants. Allergens are your own tissue, modified under the action of LV. Haematological disease due to such exposure can cause antihypertensive drugs, sulfonamides, antibiotics.
  3. Immunocomplex. This is the result of the combined effect of the allergen with IgM, IgE and IgG. The victim allergic alveolitis and serum sickness, the symptoms of which is manifested by itching, hives, fever. This effect can occur after taking penicillin and sulfanilamide.
  4. Slow. It is a skin manifestation that occurs after exposure of the medication in the form of a cream, ointment, emulsion or suspension on the skin. In addition, delayed manifestation of an Allergy may be the result of an organ transplant or rheumatic fever. In this case, the early phase is missing, immediately comes the reaction of the immune system due to lymphocytes and microphages.

To prevent allergies and the only way is not to take the medication that causes it, and alert the attending physician about developing allergic reactions to a particular drug. If the drug is taken for the first time, you must first enter it under the skin or spread a small area on the back side of the forearm and look at the result.

The toxic effects of medicines often takes place it if overused. Individual response to used in medical practice drugs occurs less frequently, and usually provoke allergies paracetamol and penicillin. Predict what the answer will follow on the acceptance of a drug, impossible. However, the LP as antibiotics, tranquilizers and hormones, must be taken strictly under medical supervision, in order to start an irreversible process and not to harm your health.