Allergic reactions: urticaria, rash, Quincke’s edema, fever, eosinophilia, bronchospasm, anaphylactic shock (more often when using benzylpenicillin). Measures to help with the development of anaphylactic shock: ensuring the airway patency, oxygen cushion, adrenaline, prednisone.
From the Central nervous system: headache, tremors, convulsions (more often in children and in patients with renal insufficiency when using carbenicillin or very high doses of benzylpenicillin); mental disorders (when administering large doses of benzylpenicillin procaine).
From the gastrointestinal tract: abdominal pain, nausea, vomiting, diarrhea, colitis (more often when using ampicillin and inhibitor-protected penicillins). If you suspect colitis (the appearance of liquid stools with blood), stop using the drug and conduct an appropriate study. Assistance measures: restoring the water-electrolyte balance;
Electrolyte balance disorders: hyperkalemia when using high doses of benzylpenicillin in patients with renal insufficiency, especially when combined with potassium-sparing diuretics and potassium preparations; hypernatremia (more often when using carbenicillin, less often – ureidopenicillins and high doses of benzylpenicillin), which may be accompanied by the appearance or increase of edema (in patients with heart failure) and increased blood pressure.
Local reactions: soreness and infiltration with intramuscular administration (especially benzylpenicillin), phlebitis (inflammation of the veins) with intravenous administration (more often when using carbenicillin).
Liver: increased activity of transaminases, which may be accompanied by fever, nausea, vomiting (more often when using oxacillin in doses of more than 6 g per day or inhibitor-protected penicillins).
Hematological reactions: lowering the level of hemoglobin, neutropenia (decrease in the level of neutrophils in the blood, more often when using oxacillin); violation of platelet aggregation, sometimes with thrombocytopenia (decrease in platelet levels when using carbenicillin, less often – ureidopenicillins).
Kidneys: transient hematuria in children (more often when using oxacillin); nephritis (very rarely).
Vascular complications (caused by benzylpenicillin procaine and benzatine benzylpenicillin): Onet syndrome – ischemia and gangrene of the extremities when injected into an artery; Nicolau syndrome – thrombosis of the lung and brain vessels when injected into a vein. Preventive measures: strictly intramuscular injection into the upper outer quadrant of the buttock; the patient must lie down during the injection.
Others: non-allergic rash that is not accompanied by itching and may disappear without discontinuation of the drug (sometimes observed when using aminopenicillins). Oral candidiasis and (or) vaginal candidiasis (when using amino-, carboxy-, ureidopenicillins).