8 USE IN SPECIFIC POPULATIONS
The available data on the use of MARCAINE SPINAL in pregnant women do not establish the presence or absence of developmental toxicity related to the use of MARCAINE SPINAL.
In animal studies, embryo-fetal lethality was noted when bupivacaine was administered subcutaneously to pregnant rabbits during organogenesis and decreased pup survival was observed in a rat pre- and post-natal developmental study (dosing from implantation through weaning). These effects were observed at dose levels approximately 30 times the daily maximum recommended human dose (MRHD) on a body surface area (BSA) basis. Based on animal data, advise pregnant women of the potential risk to a fetus (see Data).
Local anesthetics rapidly cross the placenta, and when used for epidural, caudal, or pudendal block anesthesia, can cause varying degrees of maternal, fetal, and neonatal toxicity [see Clinical Pharmacology (12.3)]. The incidence and degree of toxicity depend upon the procedure performed, the type, and amount of drug used, and the technique of drug administration. Adverse reactions in the parturient, fetus, and neonate involve alterations of the CNS, peripheral vascular tone, and cardiac function.
If this drug is used during pregnancy or if the patient becomes pregnant while taking this drug, inform the patient of the potential hazard to the fetus. The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2–4% and 15–20%, respectively.
Maternal Adverse Reactions
Maternal hypotension has resulted from regional and neuraxial anesthesia. Local anesthetics produce vasodilation by blocking sympathetic nerves. The supine position is dangerous in pregnant women at term because of aortocaval compression by the gravid uterus. Therefore, during treatment of systemic toxicity, maternal hypotension, or fetal bradycardia following regional or neuraxial block, the parturient should be maintained in the left lateral decubitus position if possible, or manual displacement of the uterus off the great vessels be accomplished. Elevating the patient's legs and right-side-up positioning will help prevent decreases in blood pressure. The fetal heart rate also should be monitored continuously and electronic fetal monitoring is highly advisable.
Labor or Delivery
Spinal anesthesia is commonly used during labor and delivery. Bupivacaine hydrochloride, when administered properly, via the epidural route in doses 10 to 12 times the amount used in spinal anesthesia has been used for obstetrical analgesia and anesthesia without evidence of adverse effects on the fetus.
Spinal anesthesia may alter the forces of parturition through changes in uterine contractility or maternal expulsive efforts. Spinal anesthesia has also been reported to prolong the second stage of labor by removing the parturient's reflex urge to bear down or by interfering with motor function. The use of obstetrical anesthesia may increase the need for forceps assistance.
The use of some local anesthetic drug products during labor and delivery may be followed by diminished muscle strength and tone for the first day or two of life. This has not been reported with bupivacaine.
It is extremely important to avoid aortocaval compression by the gravid uterus during administrations of regional or neuraxial block to parturients. To do this, the patient must be maintained in the left lateral decubitus position or a blanket roll or sandbag may be placed beneath the right hip and the gravid uterus displaced to the left.
Bupivacaine hydrochloride produced developmental toxicity when administered subcutaneously to pregnant rats and rabbits at doses 30-times the MHRD.
Bupivacaine hydrochloride was administered subcutaneously to rats at doses of 4.4, 13.3, and 40 mg/kg and to rabbits at doses of 1.3, 5.8, and 22.2 mg/kg during the period of organogenesis (implantation to closure of the hard palate). The high doses are approximately 30-times the daily MRHD of 12 mg/day on a mg dose/m2 BSA basis. No embryo-fetal effects were observed in rats at the high dose which caused increased maternal lethality. An increase in embryo-fetal deaths was observed in rabbits at the high dose in the absence of maternal toxicity with the fetal No Observed Adverse Effect Level being approximately 8-times the MRHD on a BSA basis.
In a rat pre- and post-natal development study (dosing from implantation through weaning) conducted at subcutaneous doses of 4.4, 13.3, and 40 mg/kg, decreased pup survival was observed at the high dose. The high dose is approximately 30-times the daily MRHD of 12 mg/day on a BSA basis.
Lactation studies have not been conducted with bupivacaine. Bupivacaine has been reported to be excreted in human milk suggesting that the nursing infant could be theoretically exposed to a dose of the drug. MARCAINE SPINAL should be administered to lactating women only if clearly indicated. Studies assessing the effects of MARCAINE SPINAL in breastfed children have not been performed. Studies to assess the effect of MARCAINE SPINAL on milk production or excretion have not been performed. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for bupivacaine and any potential adverse effects on the breastfed child from bupivacaine or from the underlying maternal condition.
8.4 Pediatric Use
MARCAINE SPINAL is approved for use in adults only. Administration of MARCAINE SPINAL in patients younger than 18 is not recommended.
8.5 Geriatric Use
Patients 65 years and over, particularly those with hypertension, may be at increased risk for developing hypotension while undergoing spinal anesthesia with MARCAINE SPINAL.
In clinical studies of bupivacaine, elderly patients exhibited a greater spread and higher maximal level of anesthesia than younger patients. Elderly patients also reached the maximal level of anesthesia more rapidly than younger patients, and exhibited a faster onset of motor blockade.
Differences in various pharmacokinetic parameters have been observed between elderly and younger patients [see Clinical Pharmacology (12.3)].
This product is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. Elderly patients may require lower doses of MARCAINE SPINAL.
8.6 Hepatic Impairment
Amide-type local anesthetics, such as bupivacaine, are metabolized by the liver. Patients with severe hepatic impairment, because of their inability to metabolize local anesthetics normally, are at a greater risk of developing toxic plasma concentrations, and potentially local anesthetic systemic toxicity. Therefore, consider reduced dosing and increased monitoring for local anesthetic systemic toxicity in patients with moderate to severe hepatic impairment treated with MARCAINE SPINAL [see Warnings and Precautions (5.10)].
8.7 Renal Impairment
Bupivacaine is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with renal impairment. This should be considered when selecting the MARCAINE SPINAL dosage [see Use in Specific Populations (8.5)].