An intradermal study of the local anaesthetic and vascular effects of the isomers of bupivacaine.

Abstract

1 L(‐)‐ and D(+)‐bupivacaine in eight different concentrations from 0.06 to 7.69 mmol/l (0.002–0.25%) and physiological saline were given intradermally to seventeen volunteers, using a double‐blind technique. 2 Local colour changes were observed as 'nil', 'pink' or 'pale' and analgesia to pinprick was assessed every 10 min to give an estimate of apparent in vivo potency and duration of action (50% recovery). 3 Both isomers were vasodilator in all cases at 7.69 mmol/l, but the incidence of vasodilatation waned with decreasing concentration, more rapidly with L(‐)‐than with D(+)‐bupivacaine. 4 Only L(‐)‐bupivacaine showed a vasoconstrictor effect. This was maximal at a concentration of 0.48 mmol/l, when the incidence of pallor was 92%. 5 L(‐)‐bupivacaine had a longer duration of analgesic action than the (D+)‐isomer from 0.48‐3.84 mmol/l; this was reflected in a higher apparent in vivo potency.

Tissue distribution of bupivacaine enantiomers in sheep

“…12. 4 Other investigations have shown (-)-6)-bupivacaine to be less toxic than (+)-(Sbbupivacaine in rodents in v i v~l ,~ and in a guinea pig papillary muscle preparation in vitro. It has been postulated that a stereospecific receptor site at the sodium channel is involved in the membrane stabilizing action of this agent.…”

Bupivacaína levógira a 0,5% pura versus mistura enantiomérica de bupivacaína (S75-R25) a 0,5% em anestesia peridural para cirurgia de varizes

“…This contradiction could be explained by microvascular stereoselectivity. Isomer S(-) is more vasoconstrictor than isomer R(+) as confirmed by Aps and Reynolds 17 . This effect should favor a delay in uptaking and redistributing the drug in the injection site.…”

Levobupivacaine induces vasodilatation, but not vasoconstriction, in rat mesenteric artery

“…It was observed that these anesthetics cause vasodilatation at high concentrations, and vasoconstriction at smaller concentrations, both in vivo and in vitro [16][17][18][19] .…”

“…Studies showed that LEVO in 50% enantiomeric excess induced certain intrinsic vasoconstriction in vitro [8][9][10]12,16 and in vivo [17][18][19] . Therefore, this study aimed to assess the vasoactivity of LEVO in in vitro experiments using arterial rings prepared from isolated rat superior mesenteric artery, a resistant artery, which can reflect the possible effects on the vascular reactivity in smaller blood vessels such as those present in the area treated by local anesthetic in clinical dentistry.…”