Sulfa drugs — list and classification, mechanism of action and contraindications

Familiar people the sulfonamides have proved themselves, as there was before the story of the discovery of penicillin. To date, these drugs in pharmacology has partially lost its importance, since the efficiency inferior to modern medicine. However, in the treatment of some pathologies, they are irreplaceable.

What is sulfa drugs

To sulfanilamide (sulfonamides) are synthetic antimicrobial drugs that are derivatives of sulfanilic acid (aminobenzenesulfamido). The sulfonamide sodium inhibits the activity cocci and rods affects Nocardia, malaria, Plasmodium, Proteus, chlamydia, Toxoplasma, has a bacteriostatic effect. Sulfa drugs are drugs that are prescribed for the treatment of diseases caused by pathogens resistant to antibiotics.

Classification of sulfa drugs

In their activity means inferior to sulfa antibiotics (not to be confused with sulfonanilide). These drugs have high toxicity, so they have a limited range of indications. Classification of sulfa drugs divided into 4 groups, depending on the pharmacokinetics and properties:

  1. Sulfonamide rapidly absorbed from the gastrointestinal tract. Their prescribed for systemic treatment of infections caused by susceptible microorganisms: Etazol, Sulfadimetoksin, Sulfamethizol, Sulfadimidin (Sulfadimidine), Sulfocarbamoyl.
  2. Sulfonamides, incompletely or slowly absorbed. They create in the large and small intestines high concentration: sulgin, Ftalazol, Ftazin. Etazol-sodium
  3. Sulfonamides topical application. Well established in ocular therapy: Sulfatsil sodium (Sulfacetamide, Sulfacetamide), silver Sulfadiazine (Dermazin), Mafenide acetate ointment 10% Ointment of streptocid on the 10%.
  4. Salazosulfapyridine. This classification of sulfonamides compounds with salicylic acid: Sulfasalazine, Salazopyrin.

The mechanism of action of sulfa drugs

The choice of medication for treatment of the patient depends on the properties of the pathogen, because the mechanism of action of sulfonamides is reduced to blocking of sensitive microorganisms in the cells of the synthesis of folic acid. For this reason, some medications, for example, Novocaine or Metaanalysis incompatible with them, as they weaken the action. A key principle of action of sulfonamides – a violation of the metabolism of microorganisms, inhibit their reproduction and growth.

Indications for use of sulfonamides

Depending on the structure of sulfide drugs have the General formula, but differing pharmacokinetics. There are dosage forms for intravenous injection: Sulfacetamide sodium, Streptocid. Some drugs administered intramuscularly: Sulfalen, Sulfadoxine. Combination drugs are used both ways. For children sulfonamide used topically or in pill: Co-trimoxazole-Rivopharm, Cotripharm. Indications of sulfonamides:

  • folliculitis, acne vulgaris, erysipelas;
  • impetigo;
  • burns 1 and 2 degrees;
  • pyoderma, carbuncles, boils;
  • purulent-inflammatory processes on the skin;
  • infected wounds of different origin;
  • tonsillitis;
  • bronchitis;
  • eye diseases.

A list of sulfa drugs

The period of circulation, the antibiotic sulfonamides are divided into: short, medium, long and extremely long exposure. Make a list of all drugs is impossible, therefore this table presents long-acting sulfonamides used to treat many bacteria:





silver sulfadiazine

infected burns and surface wounds

Quick help

silver sulfadiazine

burns of any etiology, minor injuries, trophic ulcers



pathology caused by cocci, including gonorrhea, pneumonia, dysentery



of the urinary tract infection, respiratory tract, soft tissues, skin



toxoplasmosis, malaria, primary polycythemia

Prontosil (Red streptocid)


strep pneumonia, puerperal sepsis, erysipelas of the skin

Combined sulfa drug

Time does not stand still, and many strains of microbes have mutated and adapted. Doctors have found a new way to combat bacteria – created combo sulfa drug, in which antibiotics are combined with trimethoprim. The list of such selfoperated:





sulfamethoxazole, trimethoprim

infection of the gastrointestinal tract, uncomplicated gonorrhea, and other infectious diseases.


sulfamethoxazole, trimethoprim

chronic or acute bronchitis, lung abscess, bacterial diarrhoea, cystitis and other


sulfamethoxazole, trimethoprim

antibacterial, Antiprotozoal, antibacterial agent broad spectrum


sulfamethoxazole, trimethoprim

typhoid fever, acute brucellosis, abscess of the brain, inguinal granuloma, prostatitis and other

Sulfa drugs for children

Since these drugs are the drugs of wide spectrum of action, their use in Pediatrics. Sulfa drugs for children are produced in tablets, granules, ointments and solutions for injections. Medication list:





sulfamethoxazole, trimethoprim

from 6 years: gastroenteritis, pneumonia, wound infection, acne

Etazola pills


from 1 year of age: pneumonia, bronchitis, tonsillitis, peritonitis, erysipelas


silver sulfadiazine

than 1 year: non-healing wounds, bedsores, burns, ulcers



from 6 years: respiratory tract infections, genitourinary system, skin disease

Instructions for use of sulfonamides

Antibacterials prescribed both internally and topically. Instructions for use of sulfonamides States that children will use the drug: 0.05 g, from 2 to 5 years – 0.3 g, 6 to 12 years – 0.6 g for the whole reception. Adults are 5-6 times/day 0.6 to 1.2 g. the Duration of treatment depends on the severity of the pathology and is appointed by the doctor. At annotation the course is 7 days. Any sulfa drug should drink alkaline liquid and to use products that contain sulfur to maintain the urine and prevent crystallization.

Side effects sulfa drugs

Prolonged or uncontrolled use can occur side effects of sulfonamides. It is an allergic reaction, nausea, dizziness, headaches, vomiting. In systemic absorption sulforaphane can pass through the placenta and then be detected in fetal blood causing toxic effects. For this reason, during pregnancy the safety of medication in question. The physician should consider such chemotherapeutic effect when assigning them to pregnant women and during lactation. Contraindications to the use of sulfonamides is:

  • hypersensitivity to the main component;
  • anemia;
  • porphyria;
  • liver or kidney failure;
  • pathology of the hematopoietic system;
  • azotemia.

Price sulfa drugs

Drugs of this group are not a problem to buy in online store or in a pharmacy. The difference in cost is significant, if you order the catalog online several drugs. If you buy the medicine in a single embodiment, it will have to pay extra for shipping. Inexpensive cost sulfonamides domestic production, while imported drugs are much more expensive. Approximate price of sulfa drugs:



Price in rubles

Sulfanilamide (streptocid White) 250 g



Biseptol 20 PCs 120 mg



Enersul 100 ml

The Republic Of Croatia


Will sumetrolim 20 PCs 400 mg



Video: what is sulfonamides

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