Lidocaine hydrochloride injection is available in concentrations of 0.5, 1, 1.5, and 2% (5, 10, 15, and 20 mg/mL, respectively) in single-dose (preservative-free) plastic or glass vials, ampuls, and syringes, and in 10- to 50-mL multiple-dose vials along with sodium chloride; sodium hydroxide and/or hydrochloric acid are used for pH adjustment.3816; 3817 Multiple-dose vials contain methylparaben 1 mg/mL as a preservative.3816
Lidocaine hydrochloride injection also is available with epinephrine 1:200,000 or 1:100,000 as the bitartrate in single-dose (preservative-free) vials and multiple-dose vials along with sodium chloride, sodium metabisulfite, and citric acid.3816 In addition to lidocaine hydrochloride, each mL contains epinephrine 0.005 mg (1:200,000) or 0.01 mg (1:100,000).3816 Multiple-dose vials contain methylparaben 1 mg/mL as a preservative.3816 Solutions may contain sodium hydroxide and/or hydrochloric acid for pH adjustment.3816
Lidocaine hydrochloride also is available as a premixed infusion solution at concentrations of 0.4 and 0.8% in dextrose 5% in single-use plastic containers.3818 The 0.4% solution contains 4 mg/mL of lidocaine hydrochloride and the 0.8% solution contains 8 mg/mL of lidocaine hydrochloride in dextrose 5%.3818
pH
Lidocaine hydrochloride injection has a pH of 5 to 7.3816; 3817 Lidocaine hydrochloride with epinephrine injection has a pH of approximately 4.5 (3.3 to 5.5).3816
The premixed infusion solutions in dextrose 5% have a pH of 3 to 7.3818
Osmolality
The osmolalities of lidocaine hydrochloride products were determined to be 296 mOsm/kg for the 10-mg/mL concentration and 352 mOsm/kg for the 20-mg/mL concentration.1233
Osmolarity
The 0.4 and 0.8% premixed infusion solutions have osmolarities of approximately 280 and 305 mOsm/L, respectively.3818
Trade Name(s)
Xylocaine
Lidocaine hydrochloride is administered by direct intravenous injection and continuous intravenous infusion.3817; 3818 The drug also may be administered by intramuscular injection.118; 119; 120; 3817 Lidocaine hydrochloride also may be administered by local infiltration, local injection, intravenous injection for intravenous regional anesthesia, or caudal or epidural injection.3816 For caudal or epidural administration, only preservative-free formulations should be used.3816 For intravenous regional anesthesia, only the 0.5% lidocaine hydrochloride injection in 50-mL single-dose vials should be used; formulations containing epinephrine should not be used.3816
Intact containers of lidocaine hydrochloride injection should be stored at controlled room temperature.3816; 3817 Products containing epinephrine should be protected from light.3816 The solution should not be used if a pinkish or darker than slightly yellow color develops or if particulate matter is present.3816 Single-dose vials contain no preservative; unused portions should be discarded.3816
The premixed infusion solution should be stored at controlled room temperature and protected from freezing.3818 The manufacturer states that brief exposure up to 40°C does not adversely affect the product, but excessive heat should be avoided.3818
Autoclaving
Lidocaine hydrochloride without epinephrine may be autoclaved.3816 Products containing epinephrine should not be autoclaved.3816
pH Effects
Although lidocaine hydrochloride is stable across a broad pH range, its pH of maximum stability is 3 to 6.1277
Buffering lidocaine hydrochloride injection with sodium bicarbonate has been used to reduce pain on injection. Increasing the pH results in an increased percentage of the drug being present as the unionized base, which is less stable and soluble. Lidocaine base precipitation has been shown to occur at a pH around 7.5 to 7.6.2409
The stability of lidocaine hydrochloride 2%, with and without epinephrine hydrochloride, was studied after alkalinization with sodium bicarbonate. Lidocaine hydrochloride alone was alkalinized to pH 7.2, while the lidocaine-epinephrine combination was adjusted to pH 6.5 and also 7.05. The combinations were compatible, and no loss of lidocaine or epinephrine occurred over 6 hours.1401
The stability of lidocaine hydrochloride 1% (Elkins-Sinn) buffered with sodium bicarbonate to pH 6.8, 7.2, and 7.4 was evaluated. No loss occurred in 27 days at pH 6.8. At pH 7.2, adequate concentrations were retained for 19 days, but by 27 days, concentrations had fallen to about 88% and a crystalline precipitate formed. At pH 7.4, losses of up to 23% were accompanied by crystalline precipitation between 5 and 15 days.2407
Lidocaine hydrochloride is stable when mixed with certain acid-stable drugs such as epinephrine hydrochloride, norepinephrine bitartrate, and isoproterenol hydrochloride. However, its buffering action may raise the pH of intravenous admixtures above 5.5, the maximum pH for stability of the other drugs. The final pH is usually about 6. These drugs begin to deteriorate within several hours. Note: This does not apply to commercial lidocaine-epinephrine combinations, which have the pH adjusted to retain epinephrine.24
Syringes
Lidocaine hydrochloride (Abbott) 20 mg/mL was packaged as 10 mL of undiluted injection in 12-mL polypropylene syringes (Becton Dickinson) and stored at 23°C under fluorescent light and 4°C. No lidocaine loss was found after 90 days of storage.2428
Lidocaine hydrochloride 2% (20 mg/mL) in auto-injector syringes (Abbott) was evaluated for stability over 45 days under use conditions in paramedic vehicles. Temperatures fluctuated with locations and conditions and ranged from 6.5°C (43.7 °F) to 52°C (125.6 °F) in high desert conditions. No visually apparent changes occurred, and no loss was found.2548
Lidocaine hydrochloride under simulated summer conditions in paramedic vehicles was exposed to temperatures ranging from 26 to 38°C over 4 weeks. No loss of the drug occurred.2562
Sorption
Lidocaine hydrochloride in solutions with acidic pH was shown not to exhibit sorption to polyvinyl chloride (PVC) bags and tubing, elastomeric pump reservoirs, polyethylene tubing, Silastic tubing, and polypropylene syringes.12; 536; 606; 2014
However, in a slightly alkaline (pH 8) cardioplegia solution, the percentage of unionized lidocaine base increased to 58%. This compares to 3% in dextrose 5% and sodium chloride 0.9% at around pH 6. The unionized form is highly lipid soluble and may interact with PVC bags. Storage of the cardioplegia solutions in PVC bags at 22°C resulted in a 12 to 19% lidocaine loss in 2 days and a 65 to 75% loss in 21 days. Degradation was not likely because storage in glass bottles did not result in any lidocaine loss after 21 days at 22°C. Refrigeration of the PVC bags at 4°C slowed the lidocaine loss to 9% or less in 21 days.776
Filtration
Lidocaine hydrochloride (Astra) 200 mg/L in dextrose 5% and sodium chloride 0.9% did not display significant sorption to a 0.45-µm cellulose membrane filter (Abbott S-A-I-F) during an 8-hour simulated infusion.567
Central Venous Catheter
Lidocaine hydrochloride (Astra) 2 mg/mL in dextrose 5% was found to be compatible with the ARROWg+ard Blue Plus (Arrow International) chlorhexidine-bearing triple-lumen central catheter. Essentially complete delivery of the drug was found with little or no drug loss occurring. Furthermore, chlorhexidine delivered from the catheter remained at trace amounts with no substantial increase due to the delivery of the drug through the catheter.2335
Standardize 4 Safety
One or more standardized concentrations for this drug have been established through Standardize 4 Safety (S4S), a national patient safety initiative to reduce medication errors, especially during transitions of care. (See Standardize 4 Safety in Users Guide.) Recommendations developed to date through this initiative are available at www.ashp.org/pharmacy-practice/standardize-4-safety-initiative.
Table 1: Standardize 4 Safety Continuous IV Infusion Standard Concentrations for Lidocaine3635; 3636
| Patient Population | Concentration Standards | Dosing Units |
|---|---|---|
| Adults | 8 mg/mL | mg/minute |
| Pediatric patients (50 kg)a | 4 mg/mL 8 mg/mL | mcg/kg/minute (note dosing units differ from concentration units) |
a The recommended concentrations are intended for cardiac indications only.
For a list of references cited in the text of this monograph, search the monograph titled References.