Some side effects of antibiotics are common among groups of antibiotics, but most are related to individual drugs. Even within the same group of antibiotics, cross reactions to side effects are diverse. Therefore, clinicians should be aware of the characteristic side effects of each group, but also the typical side effects of individual antibiotics. It is not recommended that patients use drugs that have had side effects in the past. And patients also need to know exactly what medications the side effects are caused by if they have experienced severe side effects. Here are a few examples of typical side effects of antibiotics.
1. Hematological side effects
Hematological side effects are commonly caused by various antibiotics, including anemia, leukopenia, and thrombocytopenia. Among them, leukopenia and thrombocytopenia are the most common in connection with antibiotic treatment, and beta-lactam antibiotic and sulfa antibiotic are the most common causes.
Anemia occurs relatively infrequently. Beta lactam antibiotics can cause autoimmune hemolytic anemia, and trimethoprim-sulfamethoxazole can cause megaloblastic anemia caused by folic acid deficiency. Chloampenicol, which has been used in the past, can cause irreversible aplastic anemia, regardless of the dose, when administered orally, rectally, topically or intramuscularly, and not intravenously.
Some antibiotics cause platelet dysfunction and cause hemorrhagic side effects.
2. Hypersensitivity reaction
Fever is the most common hypersensitivity side effect of antibiotics, and about 10-15% of inpatient fever has been reported as fever caused by antibiotic side effects. Fever can be caused by any antibiotic, but it is also difficult to find the agent that caused the fever because it is also caused by drugs other than antibiotics. If the symptoms of the infectious disease are improving and the fever occurs again without any specific cause, it is necessary to consider whether or not it is a side effect of antibiotics. Normally, it returns to normal body temperature within 72 hours after stopping the causative agent.
Drug rashes can be caused by almost any drug that causes fever. It may appear locally, but it may be systemic and severe.
Skin findings can range from a hemorrhoidal rash to Stephen’s Johnson syndrome, where the epidermis is peeled off, can exhibit bleeding patterns, and almost all cases are accompanied by pruritus depending on clinical course. If vancomycin is injected quickly, histamine-mediated reactions can cause red man’s syndrome, which causes the facial area to glow red.
Anaphylaxis is most frequently seen with beta-lactam antibiotics, with penicillin shock being the representative. Screening is performed by skin reaction test before drug administration, but it is difficult to predict other than by penicillin, and it is not 100% predictable by penicillin.
3. Nervous system side effects
Antibiotics can cause a variety of neurological side effects. Serious side effects include encephalitis, seizures, blocking nerve muscles, muscle stiffness, ototoxicity, and blindness. Neuromuscular blockade can occur when a large amount of aminoglycoside group antibiotics are absorbed into the lungs, such as by spraying or washing the abdominal cavity, which can cause temporary respiratory arrest. Ototoxicity is most common when aminoglycosides or erythromycin are administered parenterally. Ototoxicity is classified as hearing loss due to cochlear abnormalities and dizziness due to abnormal vestibular organs, and aminoglycosides are related to both. Hearing loss due to cochlear toxicity is irreversible and occurs when the level of aminoglycoside in the blood remains high for a long period of time. On the other hand, dizziness usually goes away within 2-3 days of stopping the medication. Antibiotic-related blindness is a very rare side effect and can be caused by optic nerve toxicity caused by ethambutol, an anti-tuberculosis drug. Optic neurotoxicity can occur when tambutol is administered in excess of 25 mg / kg body weight, which can lead to blindness. If the patient feels a change in vision when reading a book or newspaper while taking anti-tuberculosis drugs, a precise eye examination should be done.
4. Heart side effects
Heart conduction disorders are not easily caused by antibiotics, but this can cause side effects such as ventricular arrhythmias. Some of the quinolone group antibiotics can cause heart conduction disorder. In rare cases, it may cause hypotension.
5. Gastrointestinal side effects
Various drugs cause gastrointestinal side effects such as nausea and vomiting, and antibiotics are no exception. Among antibiotics, oral administration of macrolide antibiotics is the most difficult, and in severe cases, the drug may need to be stopped. Antibiotic-related diarrhea is caused by a variety of mechanisms. Antibiotics cause changes in the flora of the large intestine, causing bacteria that secrete toxins to multiply, causing diarrhea and enteritis caused by toxins. On the other hand, a change in the flora of the large intestine causes a disorder in the fermentation of carbohydrates, which increases the osmotic concentration in the intestinal lumen, which may cause diarrhea. Oral antibiotics, usually absorbed by more than 90% in the proximal gastrointestinal tract, are not associated with nausea, vomiting, or irritating diarrhea.
6. Liver side effects
Liver side effects caused by antibiotics include drug-induced hepatitis, disorders of bile secretion, and liver necrosis. Mild and transient rises in serum aminotransferase are commonly caused by a wide variety of medications, which can be recovered within a few days of discontinuation. Bile secretion disorder is often caused by drugs other than antibiotics, and among antibiotics, erythromycin is the most common trigger.
7. Nephrotoxic side effects
Nephrotoxicity is either glomerular or tubular toxicity, and is caused by various antibiotics. Aminoglycosides and vancomycin are typical neotoxic antibiotics. A tubular dysfunction caused by aminoglycosides usually occurs when antibiotics are given intravenously several times a day for more than 2 weeks. Reducing the use of aminoglycosides to as little as two weeks, and once a day, the chances of nephrotoxicity are very low. Vancomycin can cause nephrotoxicity when there are risk factors such as pre-existing renal failure, simultaneous administration with other nephrotoxic drugs, aging, and dehydration. In the event that renal toxicity occurs, discontinuation of administration will in most cases restore renal function.
8. Other side effects
Other side effects may include phlebitis, arthrosis, tendonitis and tendon rupture, and skin discoloration. In particular, quinolone is not primarily used in children because it has been reported to interfere with children’s cartilage formation. However, short-term use of 2-4 weeks does not cause cartilage development disorder or arthrosis.
Most antibiotic-related side effects recover quickly when the drug is stopped, but there are also irreversible toxicity, such as ototoxicity caused by aminoglycosides. In addition, very fatal side effects such as Stevens-Johnson syndrome can occur, so care should be taken for signs of side effects during antibiotic use. Also, in the worst case, anaphylactic shock can have fatal consequences, so a thorough history of past side effects must be taken.