Antibiotics

What Are Antibiotics?

• Medications used to treat bacterial infections by killing bacteria or inhibiting their growth.
• Do not work against viral infections like colds or flu.
• Classified based on their spectrum of activity, chemical structure, and mechanism of action.

How Do Antibiotics Work?

• Bactericidal Antibiotics: Kill bacteria directly. Examples: Penicillin, cephalosporins.
• Bacteriostatic Antibiotics: Prevent bacteria from multiplying, allowing the immune system to fight off the infection. Examples: Tetracyclines, sulfonamides.

Types of Antibiotics

Based on Spectrum of Activity

• Broad-Spectrum Antibiotics: Effective against a wide range of bacteria. Examples: Amoxicillin, ciprofloxacin.
• Narrow-Spectrum Antibiotics: Target specific types of bacteria. Examples: Penicillin G, azithromycin.

Common Classes of Antibiotics

• Penicillins: Treat infections like strep throat, ear infections. Examples: Amoxicillin, penicillin V.
• Cephalosporins: Used for respiratory, urinary, and skin infections. Examples: Ceftriaxone, cefalexin.
• Macrolides: Treat respiratory and skin infections. Examples: Azithromycin, erythromycin.
• Fluoroquinolones: Broad-spectrum, used for respiratory and urinary tract infections. Examples: Ciprofloxacin, levofloxacin.
• Tetracyclines: Treat acne, Lyme disease, and respiratory infections. Examples: Doxycycline, tetracycline.
• Aminoglycosides: Treat serious infections like sepsis. Examples: Gentamicin, amikacin.
• Sulfonamides: Used for urinary tract infections. Example: Sulfamethoxazole-trimethoprim.

Uses of Antibiotics

• Treat bacterial infections such as:
  • Respiratory infections (e.g., pneumonia, bronchitis).
  • Urinary tract infections (UTIs).
  • Skin infections (e.g., cellulitis, impetigo).
  • Ear infections (e.g., otitis media).
  • Sexually transmitted infections (STIs) like gonorrhea, chlamydia.
  • Gastrointestinal infections (e.g., H. pylori, traveler’s diarrhea).
  • Severe infections like sepsis and meningitis.
• Prevent bacterial infections in high-risk surgeries (prophylactic use).

Who Should Take Antibiotics?

• Patients diagnosed with bacterial infections confirmed by a doctor.
• Individuals at risk of severe complications from infections (e.g., immunocompromised patients).
• Not recommended for viral infections like the common cold, flu, or COVID-19.

Benefits of Antibiotics

• Rapidly eliminate bacterial infections.
• Prevent the spread of bacterial diseases.
• Reduce complications from untreated infections.
• Save lives in severe conditions like sepsis or meningitis.

Possible Side Effects

Common Side Effects

• Nausea or vomiting.
• Diarrhea.
• Stomach pain or cramps.
• Skin rash or itching.

Less Common but Serious Side Effects

• Allergic reactions (e.g., hives, swelling, difficulty breathing).
• Clostridioides difficile infection (severe diarrhea caused by disruption of gut bacteria).
• Liver damage (symptoms: yellowing of skin/eyes, dark urine).
• Kidney damage (rare but possible with certain antibiotics).
• Photosensitivity (increased sensitivity to sunlight, common with tetracyclines).

Antibiotic Resistance

• Occurs when bacteria adapt and become resistant to antibiotics.
• Caused by overuse or misuse of antibiotics.
• Leads to longer illness duration, higher medical costs, and limited treatment options.

How to Prevent Antibiotic Resistance

• Take antibiotics only when prescribed by a doctor.
• Complete the full course of treatment, even if symptoms improve.
• Never share antibiotics or use leftover medications.
• Avoid requesting antibiotics for viral infections.

Drug Interactions with Antibiotics

• Antacids and Calcium Supplements: Reduce absorption of certain antibiotics like tetracyclines.
• Blood Thinners (e.g., Warfarin): Increased risk of bleeding with some antibiotics like ciprofloxacin.
• Alcohol: Can worsen side effects or interact with antibiotics like metronidazole.
• Oral Contraceptives: Certain antibiotics may reduce their effectiveness.

Precautions Before Taking Antibiotics

• Inform your doctor if you have:
  • Allergies to any antibiotics.
  • Kidney or liver disease.
  • A history of gastrointestinal disorders (e.g., C. difficile infection).
  • Pregnancy or breastfeeding status.

Monitoring and Follow-Up

• Regular follow-ups for severe infections or prolonged antibiotic use.
• Monitor for side effects like allergic reactions or persistent diarrhea.
• Check liver or kidney function with prolonged use of certain antibiotics.

Patient Counseling Points

• Take antibiotics exactly as prescribed, without skipping doses.
• Do not stop treatment early, even if you feel better.
• Store antibiotics as directed (some require refrigeration).
• Avoid alcohol with certain antibiotics like metronidazole.
• Report side effects like rash, severe diarrhea, or difficulty breathing immediately.

FAQs About Antibiotics

Q1: Can antibiotics treat all infections?

• No, antibiotics are only effective against bacterial infections, not viral or fungal infections.

Q2: What happens if I skip a dose of antibiotics?

• Take the missed dose as soon as you remember, unless it’s close to the next dose. Do not double the dose.

Q3: Can I stop taking antibiotics if I feel better?

• No, complete the full course to ensure the infection is fully treated and to prevent resistance.

Q4: Are antibiotics safe during pregnancy?

• Some antibiotics are safe, but others should be avoided. Consult your doctor for advice.

Q5: Can antibiotics cause long-term side effects?

• Rarely, but prolonged use can lead to side effects like gut microbiome disruption or organ damage.

Q6: What should I do if I experience an allergic reaction?

• Stop taking the medication and seek immediate medical attention for symptoms like rash, swelling, or difficulty breathing.

Q7: How can I reduce antibiotic resistance?

• Use antibiotics only when prescribed, follow the prescribed dose and duration, and avoid misuse.