Which of the following statements regarding toxicity of local anesthetics is false?
A. The first signs of toxicity are dizziness, tinnitus, and nystagmusB. Systematic convulsions are rare and usually self-limited
C. Most allergic reactions are to aminoamide compounds
D. For patients allergic to local anesthetics, diphenhydramine hydrochloride 1% can be injected into the wound.
The answer is C. Most allergic reactions are to aminoamide compounds
•
Slow injections limit the chance for local anesthetic toxicity. When history of
allergy is uncertain, an antihistamine such as diphenhydrarnine injected
directly into the wound can be used as an alternative and achieves anesthesia
in approximately 30 mm.
• True allergic reactions to local anesthetics are rare, especially to aminoamide compounds such as lidocaine and bupivicaine. The ester derivatives of paraaminobenzoic acid, such as procaine, are responsible for most local anesthetic allergic reactions.
• Toxicity should be suspected in patients who complain of dizziness, tinnitus, and periorbital tingling. Rarely, systemic convulsions follow.
• True allergic reactions to local anesthetics are rare, especially to aminoamide compounds such as lidocaine and bupivicaine. The ester derivatives of paraaminobenzoic acid, such as procaine, are responsible for most local anesthetic allergic reactions.
• Toxicity should be suspected in patients who complain of dizziness, tinnitus, and periorbital tingling. Rarely, systemic convulsions follow.
• These are usually self-limited because
of rapid redistribution of the drug, with resultant lower serum levels.
