Anespine Intraspinal Injection

Each 4 ml injection contains-

• Bupivacaine Hydrochloride USP 20 mg
• Dextrose Anhydrous USP 320 mg

Bupivacaine is a long acting local anesthetic of the amide type. Bupivacaine spinal 5 mg/ml is a sterile non-glucose containing solution. Bupivacaine spinal has a rapid onset of action. The duration of analgesia is 3-5 hours in the lower thoracic and lumbar segments, which makes Bupivacaine spinal especially suitable for long lasting procedures in the lower limbs. The muscular relaxation of the lower limbs is profound, and lasts 3-4 hours, being somewhat shorter than the duration of the sensory blockade. The circulatory effects of Bupivacaine spinal are similar or less than those seen with other spinal agents. Bupivacaine spinal is well tolerated by all tissues with which it comes in contact.

The following dosage recommendations should be regarded as a guide for use in the average adult:

Spinal anesthesia for surgery: 2-4 ml (10-20 mg Bupivacaine hydrochloride) The patient's physical status and concomitant medication should be considered when deciding the dose, and the lowest dose required for adequate anesthesia should be used. Duration varies with dose, while segmental spread may be difficult to predict, especially with the isobaric (plain) solution. The dose should be reduced in the elderly and in patients in the late stages of pregnancy.

Pediatrics: Bupivacaine may be used in children. One of the differences between small children and adults is a relatively high CSF volume in infants and neonates, requiring a relatively larger dose/kg to produce the same level of block as compared to adults.

• <5 kg: 0.40-0.50 mg/kg
• 5 to 15 kg: 0.30-0.40 mg/kg
• 15 to 40 kg: 0.25-0.30 mg/kg

Bupivacaine should be used with care in patients receiving antiarrhythmic drugs with local anaesthetic activity, as their toxic effects may be additive. Phenothiazines and Butyrophenones may reduce or reverse the pressor effect of epinephrine.

General contraindications related to intrathecal anesthesia should be taken into account absolute

• Allergy or hypersensitivity to amide type local anesthetics. Detection of suspected sensitivity by skin testing is of limited value.
• Acute active diseases of the cerebrospinal system such as meningitis, tumours (primary or secondary), and poliomyelitis, subacute combined degeneration of the spinal cord, cranial haemorrhage, demyelinating disease and raised intracranial pressure.
• Spinal stenosis and active disease or recent trauma in the vertebral column.

Relative: Arthritis and other diseases of the vertebral column are relative contraindications due to technical difficulties in performing a spinal injection.

The adverse reaction profile for Bupivacaine is similar to those for other long acting local anesthetics administered intrathecally. Adverse reactions caused by the drug per se are difficult to distinguish from the physiological effects of the nerve block (e.g. decrease in blood pressure, bradycardia, temporary urinary retention), events caused directly (e.g. nerve trauma) or indirectly (e.g. epidural abscess) by the needle puncture or events associated to cerebrospinal leakage.

It is reasonable to assume that a large number of pregnant women and women of child-bearing age have been given Bupivacaine. No specific disturbances to the reproductive process have so far been reported, e.g. no increased incidence of malformations. It should be noted that the dose should be reduced in patients in the late stages of pregnancy. With recommended doses, Bupivacaine enters breast milk in such small quantities that there is generally no risk of affecting the breast-fed child. At maternal serum levels of up to 0.45 g/mL produced by the epidural use of Bupivacaine for vaginal delivery, Bupivacaine could not be detected in breast milk during the first 24 hours after delivery (detection limit 0.02 g/mL).

Local anesthetics react with certain metals and cause the release of their respective ions which, if injected, may cause severe local irritation. The ampoules are designed for single use only; any unused portions of solutions should be discarded. The solution should be used immediately after opening the ampoule. Solutions showing discoloration should not be used.

Acute emergencies associated with the use of local anesthetics are generally related to high plasma levels. Since the dose required for spinal anesthesia is so small (20% or less than that required for epidural anesthesia), acute systemic toxicity is extremely unlikely and has not been reported. With accidental intravascular injections of local anesthetics, the toxic effects will be obvious within 1-3 minutes. With over dosage, peak plasma concentrations may not be reached for 20-30 minutes, depending on the site of injection and toxic signs will be delayed. Toxic reactions mainly involve the central nervous and cardiovascular systems.

Regional anesthesia

Store at temperature not exceeding 30ºC in a dry place. Protect from light.