I. β-Lactams

1. β-Lactam antibiotics include penicillins, cephalosporins, and atypical β-lactams. These antibiotics are bactericidal during the reproductive phase.

2. The efficacy of β-lactam antibiotics mainly depends on blood concentration levels. Higher blood concentrations in a shorter time are beneficial for treatment.

3. The mechanism of β-lactam antibiotics is to inhibit bacterial cell wall synthesis, causing the loss of the protective cell wall, leading to bacterial swelling, deformation, and eventual rupture and death.

4. β-Lactam antibiotics should not be combined with chloramphenicol, tetracyclines, or macrolides due to antagonistic effects.

5. Combining β-lactam antibiotics with glucocorticoids (e.g., dexamethasone) can increase blood concentration but may also increase bleeding risk at high doses.

6. β-Lactam antibiotics can be combined with non-steroidal anti-inflammatory drugs (NSAIDs) to increase blood concentration and prolong half-life. NSAIDs include metamizole, aspirin, paracetamol, and indomethacin.

7. Combining β-lactam antibiotics with tea extracts has synergistic antibacterial effects.

II. Penicillins

1. Penicillins combined with honeysuckle (Lonicera japonica) extract have broad-spectrum antibacterial and antiviral effects, enhancing efficacy against drug-resistant Staphylococcus aureus.

2. Penicillins combined with Shuanghuanglian (a Chinese herbal extract) have synergistic effects.

3. Penicillins combined with Semiaquilegia adoxoides extract improve pneumonia treatment efficacy.

4. Penicillins combined with Wuling San reduce adverse reactions.

5. Penicillins combined with Maxing Shigan Tang improve respiratory infection treatment.

6. Oxacillin sodium combined with ranitidine increases oral absorption by over 8 times.

7. Ampicillin sodium should be administered on an empty stomach, as food reduces absorption and efficacy.

8. Amoxicillin works best with probenecid or clavulanate to enhance effects against S. aureus and Gram-negative bacilli.

9. Kanamycin combined with ampicillin has synergistic effects against E. coli.

III. Cephalosporins (Synergistic Techniques)

1. Combining cephalosporins with macrolides significantly inhibits rapid bactericidal effects (avoid mixing in drinking water).

2. Cephalosporins hydrolyze with alkaline drugs (e.g., sodium bicarbonate, aminophylline), reducing potency.

3. Cephalosporins combined with Shuanghuanglian have synergistic effects.

4. Cefotaxime sodium combined with probenecid reduces renal clearance by 5% and prolongs half-life by 45%.

IV. Aminoglycosides (Synergistic Techniques)

1. Aminoglycosides are bactericidal (not bacteriostatic), especially effective against stationary-phase bacteria, with enhanced efficacy in alkaline conditions.

2. Combining aminoglycosides with alkaline drugs (e.g., sodium bicarbonate) increases antibacterial effects and toxicity (adjust dosage).

3. Vitamin C reduces aminoglycoside efficacy.

4. Aminoglycosides combined with aminophylline increase toxicity and hearing impairment (reduce dosage).

5. Alkaline conditions from aminophylline enhance aminoglycoside efficacy and prolong half-life.

6. Aminoglycosides combined with rifampin have synergistic effects against tuberculosis.

7. Aminoglycosides combined with cimetidine cause respiratory depression (avoid combination).

8. Aminoglycosides combined with furazolidone have synergistic effects.

9. Aminoglycosides combined with tetracyclines have synergistic effects against Gram-negative bacteria.

V. Streptomycin (High-Efficacy Usage)

1. Streptomycin is poorly absorbed orally (avoid oral administration).

2. For urinary tract infections, combine streptomycin with sodium bicarbonate to alkalinize urine.

3. Streptomycin combined with oxytetracycline has synergistic effects against Gram-negative bacteria.

4. Streptomycin combined with fluoroquinolones (except enrofloxacin) has synergistic effects but increased toxicity (reduce dose or stagger administration).

5. Neomycin is poorly absorbed in the GI tract, reducing systemic toxicity.

6. Streptomycin combined with isoniazid has synergistic effects against tuberculosis.

7. Combining Eleutherococcus with streptomycin enhances anti-infective efficacy.

8. Combining Pulsatilla chinensis with streptomycin has synergistic antibacterial effects.

9. Streptomycin should not be combined with chloramphenicol (antagonistic).

10. Streptomycin combined with polymyxin E causes skeletal muscle relaxation.

11. Streptomycin mixed with glucose injection reduces potency.

VI. Gentamicin (Synergistic Techniques)

1. Vitamin E counteracts gentamicin nephrotoxicity (reduces kidney damage).

2. Gentamicin combined with fluoroquinolones has synergistic effects but increased toxicity (reduce dose).

3. Citrus aurantium increases gentamicin concentration in bile, enhancing biliary infection treatment.

4. Borneol increases gentamicin blood concentration and brain penetration (enhances efficacy, reduces dose).

5. Gentamicin combined with lincomycin has synergistic effects against streptococci but increases nephrotoxicity (risk of acute renal failure).

6. Gentamicin combined with acidic herbs (e.g., hawthorn) reduces urinary tract antibacterial efficacy.

7. Avoid combining gentamicin with other aminoglycosides (no added efficacy, increased toxicity).

VII. Tetracyclines (High-Efficacy Usage)

1. Tween-80 enhances tetracycline GI absorption.

2. Lactate TMP (trimethoprim) enhances tetracycline efficacy.

3. Chinese herbal formulas with ginseng, bupleurum, or licorice improve tetracycline efficacy and reduce toxicity.

4. Combining tetracyclines with Coptis chinensis or Pueraria lobata enhances efficacy and reduces toxicity.

5. Tetracyclines combined with fluoroquinolones reduce efficacy (avoid combination).

6. Tetracyclines combined with aminoglycosides may cause precipitation or reduced potency.

7. Alkaline drugs (e.g., sodium bicarbonate) form complexes with tetracyclines, reducing absorption.

8. Tetracyclines promote cell wall synthesis, antagonizing penicillins and cephalosporins.

9. Cimetidine reduces tetracycline efficacy (avoid combination).

10. Tetracyclines combined with aminophylline increase theophylline blood concentration and side effects.

11. Vitamin B complex inactivates most tetracyclines (avoid combination).

12. Gypsum (calcium sulfate) reduces tetracycline absorption and efficacy.

13. Sulfonamides and erythromycin (alkaline drugs) reduce tetracycline solubility and absorption (avoid combination).

VIII. Oxytetracycline (Latest Usage)

1. Polymyxin enhances oxytetracycline penetration into bacterial membranes (synergistic).

2. Oxytetracycline combined with metronidazole reduces metronidazole efficacy.

3. Vitamin C inactivates oxytetracycline, while oxytetracycline accelerates vitamin C excretion (avoid combination).

IX. Doxycycline (New Strategies)

1. Doxycycline combined with florfenicol has additive effects against E. coli.

2. Bromhexine or ambroxol increases doxycycline lung/bronchial concentration.

3. Doxycycline combined with rifampin reduces antibacterial effects.

4. Doxycycline has a similar spectrum to tetracycline/oxytetracycline but is 2–10 times more potent.

X. Macrolides (Synergistic Techniques)

1. Neomycin combined with macrolides treats Gram-positive mastitis.

2. Macrolides reduce penicillin/cephalosporin efficacy.

3. Macrolides inhibit aminophylline metabolism, increasing toxicity (reduce dose if combined).

4. Macrolides combined with chloramphenicol compete for binding sites (antagonistic, hepatotoxic; stagger dosing by 3–4 hours if necessary).

5. Macrolides combined with lincomycin/clindamycin compete for target sites (antagonistic).

6. Macrolides combined with polyether ionophores (e.g., salinomycin, hainanmycin) stunt growth or cause toxicity in poultry.

7. Shuanghuanglian mixed with macrolides causes turbidity or precipitation.

XI. Erythromycin (Clinical High-Efficacy Usage)

1. Montmorillonite (GI protectant) reduces erythromycin GI side effects and enhances efficacy.

2. Ambroxol increases erythromycin lung concentration by 27%.

3. Erythromycin combined with cephalosporins is antagonistic.

4. Erythromycin combined with enrofloxacin reduces efficacy.

5. Vitamin C reduces erythromycin potency by 20–40% (pH-dependent; stable at pH 6–7).

6. Aspirin reduces erythromycin efficacy (avoid combination).

7. Probenecid lowers erythromycin blood concentration.

8. Erythromycin is incompatible with monensin/salinomycin.

9. Erythromycin combined with tiamulin competes for binding sites (reduced efficacy).

10. Erythromycin inhibits Andrographis paniculata’s leukocyte phagocytosis.

11. Alkaline drugs (e.g., sodium bicarbonate) enhance erythromycin absorption.

12. Penicillin combined with erythromycin is antagonistic (stagger dosing if necessary).

13. Erythromycin ethylsuccinate resists gastric acid degradation (good oral absorption).

XII. Tylosin & Tilmicosin

1. Tylosin is highly effective against mycoplasma (among the strongest in macrolides).

2. Tylosin combined with tetracyclines is synergistic.

3. Tiamulin competes with tylosin for binding sites (reduced efficacy).

4. Tylosin increases toxicity of ionophores (e.g., monensin, salinomycin).

5. Tylosin combined with sulfonamides treats swine dysentery, bacterial pneumonia, enteritis, fowl cholera, and infectious coryza.

6. Tylosin/tilmicosin are more potent than erythromycin, with better absorption, fewer GI side effects, and once/twice-daily dosing (vs. erythromycin’s 3–4 doses/day).

XIII. Tilmicosin (Veterinary Expert Usage)

1. Tilmicosin (a protein synthesis inhibitor) counteracts fluoroquinolones (avoid combination).

2. Tilmicosin combined with penicillins is antagonistic.

3. Tilmicosin inhibits cephalosporin bactericidal effects.

4. Tilmicosin combined with epinephrine is lethal in pigs.

XIV. Lincosamides (High-Efficacy Usage)

1. Lactate TMP enhances lincosamide efficacy and reduces side effects.

2. Lincosamides precipitate with sulfonamides/penicillins (avoid mixing in water).

3. Lincosamides combined with fluoroquinolones are synergistic but should not be mixed.

4. Tiamulin competes with lincosamides (reduced efficacy).

5. Lincosamides combined with chloramphenicol compete for binding sites (antagonistic).

6. Lincosamides antagonize cephalosporins (except cefoxitin for mixed anaerobic/aerobic infections).

7. Lincosamides are incompatible with vitamin B complex.

8. Lincomycin enhances aminophylline effects (reduce dose if combined).

9. Cimetidine increases lincomycin bioavailability.

10. Lincomycin combined with gentamicin enhances streptococcal efficacy but increases nephrotoxicity.

11. Metronidazole combined with clindamycin is synergistic.

XV. Polymyxins (Clinical Efficacy Tips)

1. Sulfonamides/rifampin enhance polymyxin efficacy against E. coli, Klebsiella, and Pseudomonas (do not mix).

2. Lactate TMP enhances polymyxin efficacy 2–32x (synergistic against Pseudomonas).

3. Chlortetracycline, oxytetracycline, or tetracycline enhance polymyxin penetration (synergistic).

4. Polymyxin combined with cephalosporins increases nephrotoxicity.

XVI. Fluoroquinolones (Optimal Usage)

1. Fluoroquinolones combined with penicillins, cephalosporins, or lincosamides reduce resistance.

2. Fluoroquinolones combined with aminoglycosides are synergistic against Gram-negatives (especially E. coli).

3. Fluoroquinolones combined with metronidazole are synergistic against anaerobes.

4. Probenecid reduces renal clearance, increasing fluoroquinolone blood levels.

5. Metoclopramide accelerates gastric emptying, increasing norfloxacin absorption.

6. Antacids (e.g., aluminum hydroxide) reduce norfloxacin absorption (avoid concurrent use).

7. Ciprofloxacin combined with clindamycin is synergistic against streptococci/staphylococci.

8. Metoclopramide increases ciprofloxacin absorption.

9. Ciprofloxacin combined with amikacin is synergistic against Pseudomonas and S. aureus.

10. Chloramphenicol, tetracyclines, or macrolides reduce ciprofloxacin efficacy and increase toxicity.

11. Cefoperazone sodium precipitates with ciprofloxacin (rate depends on concentration).

12. Ciprofloxacin combined with bromhexine/ambroxol enhances respiratory infection treatment.

13. Ciprofloxacin combined with diphenoxylate treats bacterial enteritis in poultry/swine.

14. Enrofloxacin inhibits theophylline/caffeine metabolism (risk of toxicity).

15. Ofloxacin combined with polymyxin treats E. coli/Salmonella infections effectively.

XVII. Astragalus (Veterinary Expert Usage)

1. Astragalus injection enhances cardiac glycoside efficacy.

2. Astragalus polysaccharide combined with interferon inhibits adenovirus additively.

3. Astragalus combined with ephedra improves asthma treatment.

4. Astragalus combined with Sophora flavescens enhances leukocyte-boosting effects.

5. Astragalus (higher dose) combined with Saposhnikovia divaricata enhances immune function synergistically.

6. Astragalus combined with Codonopsis pilosula enhances phagocytic function (treats nephritis/proteinuria).

7. Astragalus combined with Leonurus japonicus (1:1) promotes blood circulation.

8. Astragalus combined with Angelica sinensis (2:1) nourishes blood; (1:1) promotes circulation.

XVIII. Amphenicols (New Strategies)

1. Tween-80 enhances amphenicol absorption.

2. Amphenicols antagonize macrolides (compete for binding sites).

3. Rifampin induces liver enzymes, reducing amphenicol blood levels (adjust dose).

4. Amphenicols combined with aminoglycosides are antagonistic and increase ototoxicity.

5. Lincosamides and amphenicols bind the same ribosomal site (antagonistic).

6. Fluoroquinolones combined with amphenicols reduce efficacy.

7. Thiamphenicol is immunosuppressive (avoid in vaccinated animals).

8. Florfenicol combined with doxycycline (1:2) treats swine eperythrozoonosis and bacterial/mycoplasma infections.

XIX. Tiamulin (Clinical Tips)

1. Tiamulin combined with tetracyclines is synergistic.

2. Chlortetracycline combined with tiamulin (4:1) treats mycoplasma/Pasteurella pneumonia effectively.

3. Tiamulin competes with lincomycin, erythromycin, and tylosin (reduced efficacy).

XX. Sulfonamides (Synergistic Techniques)

1. Sulfonamides combined with polymyxin treat resistant Pseudomonas (do not mix).

2. Sulfonamides combined with lactate TMP (5:1) enhance efficacy (bacteriostatic → bactericidal).

3. Aminophylline competes with sulfonamides for protein binding (increases theophylline levels; adjust dose).

4. Aspirin increases sulfonamide blood levels (enhanced effects/toxicity).

5. Sulfonamides impair vitamin K absorption (risk of anemia/bleeding).

6. Vitamin C reduces sulfonamide excretion (risk of renal crystallization; low-dose vitamin C is safe).

7. Paracetamol combined with sulfamethoxazole prolongs action (increased blood levels/toxicity).

8. Levamisole combined with sulfamethoxazole treats toxoplasmosis (reduces antigenic stimulation).

9. Sulfamethoxazole combined with TMP enhances efficacy (bactericidal; comparable to tetracycline/ampicillin).

10. Sulfamonomethoxine combined with DVD (5:1) enhances activity against S. aureus, E. coli, and Proteus by 10–30x.

11. TMP synergizes with sulfonamides, aminoglycosides, rifampin, lincomycin, penicillins, tetracyclines, polymyxin, and cephalosporins.

12. TMP combined with berberine is synergistic.

13. TMP combined with isoniazid treats E. coli/Salmonella effectively.

14. TMP synergizes with Houttuynia cordata but antagonizes its volatile oils.

15. TMP combined with Artemisia annua enhances antiprotozoal effects (effective against coccidiosis).

16. TMP combined with Pulsatilla chinensis, Agrimonia pilosa, or Portulaca oleracea treats E. coli/Salmonella synergistically.

17. TMP combined with high-dose/long-term paracetamol may cause anemia, thrombocytopenia, or leukopenia.