How should azithromycin be given to a rat? - briefly
Administer azithromycin to a rat by oral gavage at approximately 10 mg per kilogram of body weight once daily, using a sterile aqueous suspension. Verify the dose based on the animal’s weight and monitor for any adverse reactions.
How should azithromycin be given to a rat? - in detail
Azithromycin administration to laboratory rats requires precise dosing, appropriate formulation, and sterile technique.
First, determine the target dose. Common experimental protocols use 10–30 mg kg⁻¹ body weight per day, divided into one or two administrations. Calculate the exact amount for each animal by multiplying the selected mg kg⁻¹ value by the rat’s weight in kilograms.
Second, prepare the drug solution. Azithromycin powder dissolves readily in sterile saline or phosphate‑buffered saline (PBS) at pH 7.4. Use a concentration that allows a dosing volume of 1–2 mL kg⁻¹ to avoid excessive fluid load. For example, a 10 mg kg⁻¹ dose for a 250 g rat can be delivered as 0.25 mL of a 10 mg mL⁻¹ solution. Filter the solution through a 0.22 µm membrane to ensure sterility and store at 2–8 °C, protected from light, for no longer than 24 h.
Third, select the route. The most reliable methods are:
- Oral gavage: Use a stainless‑steel feeding needle sized for the animal’s weight. Insert gently along the esophageal axis, avoiding the trachea. Administer the calculated volume slowly to prevent regurgitation.
- Intraperitoneal injection: Employ a 25‑ or 27‑gauge needle. Inject into the lower right quadrant of the abdomen, ensuring the needle tip remains within the peritoneal cavity. Limit the volume to ≤1 mL kg⁻¹.
- Subcutaneous injection: Suitable for smaller volumes (≤0.5 mL kg⁻¹). Insert the needle at a shallow angle into the dorsal neck region, disperse the solution evenly.
Fourth, execute the dosing procedure. Restrain the rat using a manual or tube restrainer, confirm correct needle placement, and deliver the solution at a steady rate. Observe the animal for immediate adverse reactions such as respiratory distress, excessive salivation, or abnormal gait.
Finally, record each administration, including date, time, dose, route, and any observed side effects. Maintain a log of solution preparation details, including lot numbers and expiration dates, to ensure reproducibility and compliance with institutional animal care guidelines.
Adhering to these steps guarantees accurate and humane delivery of azithromycin in rodent studies.