DOSAGE AND ADMINISTRATION
When 4% Lidocaine Hydrochloride Injection, USP is used concomitantly with other products containing lidocaine, the total dose contributed by all formulations must be kept in mind.
The dosage varies and depends upon the area to be anesthetized, vascularity of the tissues, individual tolerance and the technique of anesthesia. The lowest dosage needed to provide effective anesthesia should be administered. Dosages should be reduced for children and for elderly and debilitated patients.
Although the incidence of adverse effects with 4% Lidocaine Hydrochloride Injection, USP is quite low, caution should be exercised, particularly when employing large volumes and concentrations of lidocaine since the incidence of adverse effects is directly proportional to the total dose of local anesthetic agent administered.
For specific techniques and procedures refer to standard textbooks.
There have been adverse event reports of chondrolysis in patients receiving intra-articular infusions of local anesthetics following arthroscopic and other surgical procedures. 4% Lidocaine Hydrochloride Injection, USP is not approved for this use (see WARNINGS and DOSAGE AND ADMINISTRATION).
The dosages below are for normal, healthy adults.
RETROBULBAR INJECTION: The suggested dose for a 70 kg person is 3−5 mL (120−200 mg of lidocaine HCl), i.e., 1.7−3 mg/kg or 0.9−1.5 mg/lb body weight. A portion of this is injected retrobulbarly and the rest may be used to block the facial nerve.
TRANSTRACHEAL INJECTION: For local anesthesia by the transtracheal route 2−3 mL should be injected through a large enough needle so that the injection can be made rapidly. By injecting during inspiration some of the drug will be carried into the bronchi and the resulting cough will distribute the rest of the drug over the vocal cords and the epiglottis.
Occasionally it may be necessary to spray the pharynx by oropharyngeal spray to achieve complete analgesia. For the combination of the injection and spray, it should rarely be necessary to utilize more than 5 mL (200 mg of lidocaine HCl), i.e., 3 mg/kg or 1.5 mg/lb body weight.
TOPICAL APPLICATION: For laryngoscopy, bronchoscopy and endotracheal intubation, the pharynx may be sprayed with 1−5 mL (40−200 mg of lidocaine HCl), i.e., 0.6−3 mg/kg or 0.3−1.5 mg/lb body weight.
Maximum Recommended Dosages
Normal Healthy Adults: The maximum recommended dose of 4% Lidocaine Hydrochloride Injection, USP should be such that the dose of lidocaine HCl is kept below 300 mg and in any case should not exceed 4.5 mg/kg (2 mg/lb) body weight.
Children: It is difficult to recommend a maximum dose of any drug for children since this varies as a function of age and weight. For children of less than ten years who have a normal lean body mass and normal body development, the maximum dose may be determined by the application of one of the standard pediatric drug formulas (e.g., Clark's rule). For example, in a child of five years weighing 50 lbs, the dose of lidocaine hydrochloride should not exceed 75−100 mg when calculated according to Clark's rule. In any case, the maximum dose of lidocaine hydrochloride and epinephrine injection should not exceed 7 mg/kg (3.2 mg/lb) of body weight. When used without epinephrine, the amount of lidocaine administered should be such that the dose is kept below 300 mg and in any case should not exceed 4.5 mg/kg (2 mg/lb) of body weight.
NOTE: Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever the solution and container permit. Solutions that are discolored and/or contain particulate matter should not be used. Do not use unless solution is clear and container undamaged.