3. Antacids. Classification. Mechanism of action. Indications for use. Side effects. Contraindications Comparative characteristics.

Antacids are a group of drugs that are bases that react chemically with hydrochloric acid in gastric juice and neutralize it.

1. Absorbable antacids:

Sodium bicarbonate; Precipitated calcium carbonate; Magnesium oxide; Magnesium trisilicate; Basic magnesium carbonate; Magnesium hydroxide

2. combination drugs: Rennie; Gafter's Blend

2. Non-absorbable antacids: Aluminum hydroxide

combination drugs: Protab; Almagel A; Almagel; Phospholugel; Gastal; Compensated; Alugastrin; Maalox; Gelusil varnish

Mechanism of action: Sodium bicarbonate (drinking soda) is a compound that is readily soluble in water and reacts quickly with hydrochloric acid in the stomach. This reaction takes place to produce sodium chloride, water and carbon dioxide.

Sodium bicarbonate acts almost instantly, but its effect is short-lived (10-15 minutes). The carbon dioxide formed during the reaction, accumulating in the stomach, stretches its walls, which leads to irritation of the mucous membrane receptors and increases the release of gastrin, which can lead to a secondary increase in the secretion of hydrochloric acid (syndrome of "recoil" or "secondary hypersecretion").

Calcium carbonate neutralizes hydrochloric acid to form calcium chloride, water and carbon dioxide. The antacid effect develops rapidly, because a suspension of calcium carbonate reacts with acid rather slowly, the drug acts for a longer time than sodium bicarbonate

Magnesium preparations (magnesium oxide, magnesium trisilicate, magnesium carbonate, magnesium hydroxide) are not absorbed when taken orally; neutralize hydrochloric acid to form magnesium chloride. The release of carbon dioxide during the interaction of magnesium preparations (except for magnesium carbonate) with hydrochloric acid does not occur, therefore the antacid effect is not accompanied by secondary hypersecretion. The resulting magnesium chloride is poorly absorbed in the intestine and usually does not have a systemic effect. No alkalosis phenomena are observed. With prolonged use in high doses, hypermagnesemia is possible. Passing into the intestines, magnesium chloride has a laxative effect.

Indications: Aluminum hydroxide: The drug is indicated for diseases with increased secretion of gastric juice (hydrochloric acid): ulcers, gastritis, gastroduodenitis, food poisoning, flatulence. Assign aluminum hydroxide orally in the form of a 4% aqueous suspension, 1-2 teaspoons per dose (4-6 times a day).

Almagel. The drug is prescribed individually, depending on the localization of the process, the acidity of the gastric juice.

Side effects: Aluminum hydroxide: Side effects: not all patients tolerate the astringent effect of the drug well, which may result in nausea; taking aluminum preparations is accompanied by constipation, therefore, aluminum-containing preparations are combined with magnesium preparations. In patients with renal failure, the accumulation of aluminum is not excluded, which may be accompanied by pain in the bones, muscles, encephalopathy.

Contraindications: Hypersensitivity to any component of the drug, severe renal failure, Alzheimer's disease, pregnancy.

4. Antimicrobial agents-derivatives of quinolone. Classification. Mechanism of action. The nature of the action. Spectrum of action. Indications for use. Side effects. Contraindications Comparative evaluation of drugs.

Antimicrobials are medicines used to treat infections caused by bacteria, fungi, viruses.

Classification:

1.Qinolones of the 1st generation (nalidixic acid, oxolinic acid, pipemidic acid)

2.2 Generation (ciprofloxacin, norfloxacin, ofloxacin, pefloxacin, lomefloxacin)

3.3 generation (sparfloxacin, levofloxacin)

4.4 generation (moxifloxacin, gemifloxacin)

The mechanism of action of all quinolones

- blockade of the enzyme DNA gyrase (gyrus - thread) of the microbial cell. This enzyme cross-links two DNA strands and thus participates in the processes of DNA transcription and replication. When DNA gyrase is inhibited, DNA despiralization occurs. This mechanism provides high selectivity and specificity of the quinolones action.

The nature of the action is bactericidal

All quinolones are incompatible with nitrofurans (efficiency drops sharply)

Spectrum of action I generation

non-fluorinated quinolones

narrow - Gr (-) sticks (E. coli, shigella, salmonella, protea, klebsiella)

Do not create a therapeutic concentration in blood and tissues. They are used for urinary tract infections, as they are completely excreted by the kidneys, creating therapeutic concentrations in the urine

Nalidixic acid (nevigramone, blacks)

Used 4 times a day (T1 / 2 1 - 2 hours). The effectiveness is increased by alkalinization of the urine. Microbial resistance develops rapidly

1st generation

non-fluorinated quinolones

• Indications: Acute cystitis, anti-relapse therapy of chronic pyelonephritis (in acute pyelonephritis, it is ineffective, since the drugs accumulate little in the kidney tissues)

Side effects: Gastrointestinal tract - heartburn, epigastric pain, nausea, vomiting, diarrhea (taken after meals)

CNS - an exciting effect, can manifest itself with tremors, insomnia, paresthesias, a decrease in the seizure threshold

Blood - leukopenia, thrombocytopenia, in patients with genetic deficiency of glucose-6-phosphate dehydrogenase - hemolytic anemia

Liver - cholestatic jaundice, hepatitis

• Contraindications: Fluoroquinolone: ​​History of convulsive syndromes

• Deficiency of the enzyme glucose-6-phosphate dehydrogenase

• Pregnancy (possibly inhibition of the development of cartilage tissue in the fetus)

• Lactation

• Children's age (up to 10 - 12 years old due to the possibility of inhibition of the development of cartilage tissue)

Comparative characteristics:

Nifuroxazide (enterofuril) is used for intestinal infections (acute infectious diarrhea, enterocolitis). Practically not absorbed in the digestive tract. Does not disturb the normal intestinal microflora

Furazolidone is currently used only for giardiasis as a reserve drug. NB! In combination with alcohol, it can cause a teturam-like reaction. Inhibits MAO, therefore, in combination with other MAO inhibitors, sympathomimetics, tricyclic antidepressants and tyramine-containing foods, there is a risk of developing a hypertensive crisis

Nifuratel (makmiror) is used for intestinal infections (acute infectious diarrhea, enterocolitis), giardiasis, intestinal amebiasis, trichomonas vulvovaginitis

Furacilin is used as an antiseptic for treating wounds, skin, mucous membranes, for washing serous and articular cavities.