Is local injected lidocaine (a local anesthetic) safe for use on the penis in adult males with no history of allergies or sensitivities?

Safety of Local Injected Lidocaine on the Penis

Local injected lidocaine is safe for use on the penis, and the addition of epinephrine is also safe and provides significant clinical benefits including prolonged anesthesia and improved hemostasis. 1, 2

Evidence Supporting Safety

The historical dogma that epinephrine-containing local anesthetics should be avoided in "end-arterial" territories like the penis has been definitively refuted by modern evidence:

• Multiple systematic reviews and randomized controlled trials have demonstrated no cases of necrosis when using lidocaine with epinephrine on the penis and other previously restricted areas (digits, ears, nose, hands, feet). 2, 3, 4

• The American Academy of Dermatology gives a Level A (strong) recommendation for the addition of epinephrine to local anesthesia on all body sites, including the penis. 2, 3

• A clinical study of 95 patients receiving penile ring blocks with lidocaine plus epinephrine showed no anesthetic complications and no necrosis, with high patient satisfaction and low complication rates. 5

Clinical Benefits of Adding Epinephrine

• Prolongs anesthetic duration by approximately 200% regardless of concentration (1:50,000,1:100,000, or 1:200,000). 2, 4

• Provides superior hemostasis by slowing anesthetic mobilization and reducing peak blood levels, which is particularly valuable for penile procedures. 2, 4

• Reduces systemic toxicity risk by limiting systemic absorption of lidocaine. 4

Recommended Technique and Dosing

• Use the lowest effective concentration of epinephrine (typically 1:100,000 or 1:200,000) to provide adequate pain control and vasoconstriction. 2, 4

• Maximum safe dose for adults is 7 mg/kg of lidocaine with epinephrine, which allows up to 490 mg or 49 mL of 1% solution for a 70 kg adult. 1, 4

• Most penile procedures require far less than the maximum dose—typically 3-10 mL of 1% lidocaine with epinephrine is sufficient. 4

• Buffer the lidocaine with sodium bicarbonate (1:9 or 1:10 ratio) to reduce injection pain by 20-40%—this is a Level A recommendation. 2, 4

Safety Precautions

• Aspirate before each injection to avoid intravascular injection. 4, 6

• Use incremental injections while continuously assessing the patient for early signs of toxicity (circumoral numbness, facial tingling, slurred speech, metallic taste, tinnitus). 1, 6

• Avoid using lidocaine with epinephrine within 4 hours of other local anesthetic interventions to prevent cumulative toxicity. 1, 4

• True allergy to lidocaine is rare, representing only 1% of all adverse reactions. 1

Special Populations

• Patients with stable cardiac disease may receive lidocaine with epinephrine (Level B recommendation), but consult cardiology if uncertain about tolerance. 4, 6

• For pregnant women, postpone elective procedures until after delivery, or delay until the second trimester when possible. 2, 4

• The FDA label notes that lidocaine should be used with caution in patients with hepatic disease, as amide-type local anesthetics are metabolized by the liver. 6

Common Pitfalls to Avoid

• Do not use solutions containing epinephrine for intravenous regional anesthesia. 6

• Do not buffer bupivacaine with sodium bicarbonate if mixing anesthetics, as this causes precipitation and decreased efficacy. 2

• Freshly prepared buffered solutions provide optimal vasoconstriction, as epinephrine concentration decreases by approximately 25% per week after buffering. 2