Lincomycin-Spectinomycin, commonly referred to as Li Gao Mycin, is a "2:1" compound formulation of lincomycin hydrochloride and spectinomycin hydrochloride soluble powder. Its antibacterial spectrum and activity are significantly broader and stronger compared to using either drug individually.

The spectinomycin component of Li Gao Mycin predominantly distributes in the digestive tract, heart, liver, lungs, and kidneys, with over 90% concentrating in the digestive tract. Meanwhile, lincomycin primarily distributes in the digestive tract, respiratory system, heart, and liver, with 50% to 60% of the drug found in the digestive tract.

This indicates that Li Gao Mycin is mainly effective in treating various bacterial diseases in livestock and poultry, particularly those affecting the digestive system, respiratory system, and heart and liver. However, it is far less effective or nearly ineffective for conditions like oviduct inflammation and peritonitis in poultry.

For example, Li Gao Mycin is highly effective against intestinal Escherichia coli infections and respiratory E. coli, but its efficacy against septicemic E. coli requires dosage adjustments. For reproductive E. coli infections, its efficacy is minimal.

Dosage and Disease Type

The effectiveness of Li Gao Mycin varies significantly depending on the dosage. Inadequate dosages result in poor or no therapeutic outcomes. For instance, the dosage for treating digestive tract diseases in livestock and poultry is at least twice that required for respiratory diseases.

Administration Route

The route of administration also impacts the required dosage. For respiratory diseases, the dosage for oral administration is twice that of injection due to low absorption rates of spectinomycin and partial absorption of lincomycin when administered orally. Administering the oral dose via injection is unnecessary and wasteful, and excessive doses may lead to adverse reactions.

Administration Method

For bacterial infections of the digestive tract, concentrated administration of Li Gao Mycin in drinking water is not recommended, nor is injection. Excessive concentration in drinking water can result in the drug being excreted in feces before achieving its full antibacterial effect. Conversely, overly prolonged administration can fail to maintain an effective drug concentration in the digestive tract, compromising therapeutic outcomes.

Key Recommendations

To maximize the efficacy of Li Gao Mycin:

1. Tailor the administration route, dosage, and method based on the specific disease and physiological condition of the livestock or poultry.
2. Use appropriate dosages to ensure efficacy while avoiding waste or adverse reactions.
3. Avoid overly concentrated or prolonged administration in drinking water to maintain optimal drug activity in the digestive tract.
4. Adjust dosages for systemic infections, particularly for septicemic E. coli, while recognizing its limitations for reproductive tract infections.

By following these guidelines, Li Gao Mycin can be used effectively and safely to treat bacterial infections in livestock and poultry.