Comparison : Bupivacaine Heavy VS Bupivacaine Plain

Table 1: Comparison between Bupivacaine Heavy and Bupivacaine Plain

Agents	Properties	Duration	Distribution	Pharmacokinetics	ADRs
Bupivacaine Heavy 0.5 % (MARCAINE® Spinal Heavy 5 mg/ml solution for Injection)	Contains glucose rendering is hyperbaric	Spinal administration: small dose with a relatively low concentration and short duration of action. Duration of analgesia: 2- 3 h	Initial distribution into the subarachnoid space is markedly influenced by gravity.	-Partition coeff: 2.75 -Maximum plasma concentration: 0.4 mg/ml every 100 mg injected. -Total plasma clearance: 0.58 L/min. -Vd: 73 L -Elimination half life: 2.7 h	No significant differences between both
Bupivacaine Plain 0.5 % (PIVAKAN 0.5 % w/v (Plain) Injection)	Absence of glucose; considered isobaric (slightly hypobaric at 37oC and slightly hyperbaric at 20oC)	Produces lower level of block, for a longer duration than the hyperbaric solution. Duration of analgesia: 3 – 4 h in lower thoracic and lumbar segments.	Spread is only marginally affected by gravity

Effectiveness:

• review found that intrathecal hyperbaric bupivacaine had a more rapid onset of sensory blockade at the 4th thoracic vertebra (T4) level than isobaric bupivacaine. 
• Plain bupivacaine (ie, slightly hypobaric, prepared in saline) may also be used for spinal anesthesia for cesarean delivery. 
• The literature comparing safety and efficacy of hyperbaric with isobaric bupivacaine for CD is inconclusive

Side Effects:

• There were no differences in the adverse effects studied. Any possible advantage of hyperbaric bupivacaine needs to be confirmed in larger randomized trials.

References:

1.  www.uptodate.com
2. http://www.cochrane.org/CD005143/ANAESTH_does-denser-compared-normal-bupivacaine-given-lower-back-injection-give-more-effective-and-safer
3. Product leaflets