Introduction
Antibiotics are common medications that are used in modern healthcare. These medications fight against bacterial infections in humans and animals—these either work by inhibiting bacterial growth and multiplication or killing the bacteria.
There are different routes of administration for the medication, which means these can be taken in different ways:
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Orally or through mouth in the form of capsules, pills, or liquids.
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Topical applications include ointments, creams, or sprays applied to the skin.
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Intravenous (I.V) or through injections.
Antibiotics are only effective against bacterial infections like E. coli, urinary tract infections, strep throat, etc. Some infections, like ear and sinus infections, may not require antibiotics. Reactions related to antibiotics result in one in five medication-related visits to the emergency department, and children are the most typical causes of medication-related visits to the emergency department. Therefore, antibiotics are to be taken only under the guidance of a healthcare provider; unnecessarily taking antibiotics may not be beneficial and can result in side effects.
What Are the Adverse Effects of Antibiotics on the Nervous System?
The potential side effects of antibiotics on the nervous system include seizures, encephalitis, neuromuscular blockage, muscular spasticity, etc:
1. Encephalopathy:
Encephalopathy is a wider term that refers to any disruption in brain functioning. Encephalopathy has been reported using cephalosporin, penicillin, quinolone, oxazolidinones, and sulfamethoxazole-trimethoprim.
Seizures occur due to sudden, uncoordinated electrical activity in the brain. Seizures can occur due to using quinolone, penicillin, carbapenems, and cephalosporins. Cephalosporin-associated seizures are more common in elderly individuals, in higher doses, and in those with renal impairment.
2. Non- Convulsive Status Epilepticus (NCSE):
Non-convulsive status epilepticus is characterized by persistent seizure activity with behavioral and cognitive changes. These are associated with penicillin, cephalosporin, clarithromycin, and quinolone. Diagnosis may be difficult and requires an electroencephalography for confirmation.
Some of the class-specific neurologic effects are:
3. Aminoglycosides:
Aminoglycosides result in neuromuscular blockade. This group includes drugs like streptomycin, neomycin, gentamicin, kanamycin, etc. Therefore, these groups of antibiotics are contraindicated in patients with neurological conditions like myasthenia gravis, as they can worsen neuromuscular weakness in such patients.
4. Cephalosporin:
The neurological effects associated with cephalosporin range from encephalopathy to NCSE. The independent risk factors that can increase the neurotoxic effects associated with cephalosporin are
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Excess dosage.
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Renal impairment.
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Preexisting neurological conditions.
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Reduced creatinine clearance.
5. Penicillin:
The neurotoxic effects associated with penicillin include behavioral changes, encephalopathy, seizures, and NCSE. Preexisting neurological disease can be a risk factor for encephalopathy linked with beta-lactam usage. Piperacillin has been linked with tardive seizures (these are seizures that occur after the stoppage of electroconvulsive therapy).
6. Tetracycline:
Tetracyclines are linked with neuromuscular blockade and cranial nerve toxicity. Another neurotoxic effect is associated with benign intracranial hypertension ( characterized by increased pressure in the brain, resulting in vision problems and headaches).
7. Macrolide:
These are used for managing upper respiratory tract infections and are associated with ototoxicity (inner ear damage resulting in balance and hearing issues) due to cochlear damage.
8. Quinolone:
The neurotoxic effects associated with quinolone are encephalopathy, seizures, myoclonus (brief, rapid, and involuntary jerking of muscle), and psychosis.
9. Metronidazole:
Metronidazole can result in cerebellar toxicity. These manifest as gait ataxia (impaired ability to coordinate movements for normal walking) and dysarthria (a speech disorder due to muscle weakness).
What Are the Rheumatologic and Hematologic Adverse Effects Associated With Antibiotics?
Hematologic side effects are commonly seen associated with different groups of antibiotics. Isolated cytopenia (decreased blood cell count) has been reported; these can present as anemia, thrombocytopenia (reduced platelet count), and neutropenia (decreased neutrophil count). Thrombocytopenia and leucopenia are the most common adverse effects associated with antibiotics.
Beta-lactams are found to be linked with agranulocytosis (decreased granulocyte count). Ceftriaxone and piperacillin are linked to drug-induced anemia. Drug-induced thrombocytopenia was linked with vancomycin, cephalosporin, penicillin, and sulfonamide.
Minocycline, a tetracycline antibiotic, is commonly used to treat acne vulgaris. It is associated with an uncommon adverse reaction, the development of drug-induced lupus. The condition is frequently seen in young females, and most recover from the condition on discontinuing the drug.
What Are the Adverse Effects Associated With Antibiotics on Other Systems?
1. Digestive System:
Tetracyclines can disrupt the mucosal lining and can result in esophagitis (inflammation of the esophagus).
Amoxicillin-clavulanate has been linked with drug-induced liver damage. It is commonly seen in elderly males with repeated and prolonged drug dosing. Hepatocellular injury has also been related to doxycycline.
The gastrointestinal effects associated with antibiotics are:
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Abdominal pain.
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Nausea.
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Vomiting.
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Bloating.
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Diarrhea.
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Loss of appetite.
2. Endocrine System:
Quinolone, sulfonamide, and clarithromycin can result in hypoglycemia (decreased blood glucose level) due to drug interaction with sulfonylurea. Most individuals on antibiotics (including fluoroquinolones) can develop hypoglycemia when taken with meglitinide or sulphonylureas. Those taking clarithromycin, ertapenem, cefditoren, and tigecycline may develop hypoglycemia even when not taking meglitinide or sulphonylurea.
3. Renal System:
Acute interstitial nephritis has been associated withcephalosporin, penicillin, macrolide, vancomycin, and sulfonamide. Tetracycline and cephalosporin can result in acute tubular necrosis. Sulfonamide and quinolone can lead to crystal nephropathy (precipitation of medications within the renal tubules due to their insolubility in urine; it can result in kidney injury). These are common in elderly people.
4. Cardiovascular System:
Quinolone and macrolide can result in the prolongation of the QT interval. Of the macrolides, azithromycin is considered the safest.
Ciprofloxacin is safer in terms of cardiovascular side effects. The risk factors that can increase QT prolongation in quinolone therapy include advanced age, pre-existing cardiac conditions, females, etc.
5. Reproductive System:
Antibiotics are reported to interact with the effect of oral contraceptives. The strongest association is seen in the case of rifampicin.
6. Musculoskeletal System:
Quinolone is linked with tendinitis and arthropathy. As per the FDA (Food and Drug Administration) reports, the adverse effect of fluoroquinolones outweighs the benefits in case of treatment for bronchitis, sinusitis, and uncomplicated urinary tract infections. Therefore, fluoroquinolone should be used only if other options are not possible.
7. Respiratory System:
Hypersensitivity lung disease has been linked with ampicillin, cephalosporin, penicillin, sulfonamide, and ciprofloxacin.
8. Other Effects:
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In some uncommon cases, the individual may develop allergic reactions to the antibiotics.
The symptoms include:
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Skin rashes.
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Itching.
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Coughing.
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Wheezing.
Mild to moderate allergic reactions are treated with antihistamines, but severe allergic reactions may result in anaphylaxis, which can be life-threatening.
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Another adverse effect seen with antibiotics is photosensitivity or sensitivity to light seen with tetracycline. These can result in allergic reactions following skin exposure or can result in skin irritation. One should take proper precautions against sun exposure while taking such medications.
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Tetracycline antibiotics may result in permanent tooth staining.
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Antibiotics can also increase the chance of developing yeast and other fungal infections, as the beneficial flora can also get destroyed.
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Overtake of antibiotics can result in antibiotic resistance. Antibiotic resistance occurs when the bacterial flora changes and becomes antibiotic-resistant.
Conclusion
Antibiotics should only be taken under the prescription by a health care provider, and it is given in cases where the benefits outweigh the risks. Antibiotics are ineffective in case of viral infections and are prescribed only in case of certain bacterial infections. Though a commonly prescribed medication, antibiotics should be taken with caution only under the guidance of a medical practitioner.
