Bupivacaine (Marcaine) is an amide-type long-acting local anaesthetic agent used for infiltration anesthesia, for nerve blocks, for epidural anesthesia, and spinal anesthesia. They are both available in isobaric and hyperbaric forms (Bupivacaine Plain vs Bupivacaine Heavy).
In this article, we will look at the few differences between the two forms of bupivacaine.
Bupivacaine Plain vs Bupivacaine Heavy
| Properties | Bupivacaine Plain | Bupivacaine Heavy |
| Constituents | Bupivacaine plain contains bupivacaine and excipients like Sodium chloride, Sodium hydroxide, Hydrochloric acid, and Water for injections | In addition to bupivacaine, and excipients like Sodium chloride, Sodium hydroxide, Hydrochloric acid, and Water for injections, bupivacaine heavy also contains Glucose monohydrate. |
| Pharmaceutical Form | It is a sterile, aqueous, isobaric solution which is clear, colourless and particle free. The relative density of the solution is 1.004 at 20°C | It is a sterile, hyperbaric solution which is clear, colourless and particle-free, with a specific gravity of 1.026 at 20°C |
| Clinical Indication | For or lower limb, including hip surgery, lasting 2 to 4 hours where muscle relaxation is desired or needed. Both bupivacaine plain and heavy are indicated for intrathecal (subarachnoid, spinal) anaesthesia for surgical and obstetrical procedures | For for lower abdominal surgery like Caesarean section, urological and lower limb, including hip surgery, lasting 1.5 to 3 hours. |
| It is considered isobaric (slightly hypobaric at 37oC and slightly hyperbaric at 20oC) | The glucose renders the solution hyperbaric | |
| Distribution | The spread is only marginally affected by gravity | Initial distribution into the subarachnoid space is markedly influenced by gravity. |
| Duration of action | It produces muscle relaxation in the lower limbs which lasts 3-4 hours, somewhat shorter than the duration of sensory blockade. Motor blockade of the abdominal muscles means it is suitable for abdominal surgery lasting 1.5-2 hours. | Bupivacaine heavy produces moderate muscle relaxation in the lower extremities lasting 2-3 hours. |
Similarities
- Both solutions have have a rapid onset and long duration of action
- Bupivacaine plain and heavy are indicated for intrathecal (subarachnoid, spinal) anaesthesia for surgical and obstetrical procedures
References:
- https://www.medsafe.govt.nz/profs/datasheet/m/MarcainSpinalinj.pdf
- http://askdis.blogspot.com/2015/05/comparison-between-bupivacaine-heavy.html
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6457713/
- https://ecommons.aku.edu/cgi/viewcontent.cgi?article=1308&context=pakistan_fhs_mc_anaesth
