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added information)
Fetal
Toxicity
Premature Closure of Fetal Ductus
Arteriosus:
Avoid use of NSAIDs, including Fiorinal, in pregnant
women at about 30 weeks gestation and later. NSAIDs including Fiorinal,
increase the risk of premature closure of the fetal ductus arteriosus at
approximately this gestational age.
Oligohydramnios/Neonatal Renal Impairment:
Use of NSAIDs, including Fiorinal, at about 20 weeks
gestation or later in pregnancy may cause fetal renal dysfunction leading to
oligohydramnios and, in some cases, neonatal renal impairment. These adverse
outcomes are seen, on average, after days to weeks of treatment, although
oligohydramnios has been infrequently reported as soon as 48 hours after NSAID
initiation. Oligohydramnios is often, but not always, reversible with treatment
discontinuation. Complications of prolonged oligohydramnios may, for example,
include limb contractures and delayed lung maturation. In some post-marketing
cases of impaired neonatal renal function, invasive procedures such as exchange
transfusion or dialysis were required.
If NSAID treatment is necessary between about 20 weeks
and 30 weeks gestation, limit Fiorinal use to the lowest effective dose and
shortest duration possible. Consider ultrasound monitoring of amniotic fluid if
Fiorinal treatment extends beyond 48 hours. Discontinue Fiorinal if
oligohydramnios occurs and follow up according to clinical practice [see
PRECAUTIONS; Pregnancy].
Drug
Rash with Eosinophilia and Systemic Symptoms (DRESS)
Drug Reaction with Eosinophilia and Systemic Symptoms
(DRESS) has been reported in patients taking NSAIDs such as Fiorinal. Some of
these events have been fatal or life-threatening. DRESS typically, although not
exclusively, presents with fever, rash, lymphadenopathy, and/or facial
swelling. Other clinical manifestations may include hepatitis, nephritis,
hematological abnormalities, myocarditis, or myositis. Sometimes symptoms of
DRESS may resemble an acute viral infection. Eosinophilia is often present.
Because this disorder is variable in its presentation, other organ systems not
noted here may be involved.
It is important to note that early manifestations of
hypersensitivity, such as fever or lymphadenopathy, may be present even though
rash is not evident. If such signs or symptoms are present, discontinue
Fiorinal and evaluate the patient immediately.
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added information)
Risk
Summary
Withdrawal
seizures were reported in a two-day-old male infant whose mother had taken a
butalbital-containing drug during the last 2 months of pregnancy. Butalbital
was found in the infant’s serum. The infant was given phenobarbital 5 mg/kg,
which was tapered without further seizure or other withdrawal symptoms.
Use
of NSAIDs, including Fiorinal, can cause premature closure of the fetal ductus
arteriosus and fetal renal dysfunction leading to oligohydramnios and, in some
cases, neonatal renal impairment. Because of these risks, limit dose and
duration of Fiorinal use between about 20 and 30 weeks of gestation, and avoid
Fiorinal use at about 30 weeks of gestation and later in pregnancy [see
WARNINGS; Fetal Toxicity].
Premature Closure of Fetal Ductus Arteriosus
Use
of NSAIDs, including Fiorinal, at about 30 weeks gestation or later in
pregnancy increases the risk of premature closure of the fetal ductus
arteriosus.
Oligohydramnios/Neonatal Renal Impairment
Use
of NSAIDs at about 20 weeks gestation or later in pregnancy has been associated
with cases of fetal renal dysfunction leading to oligohydramnios, and in some
cases, neonatal renal impairment.
Data
from observational studies regarding other potential embryofetal risks of NSAID
use in women in the first or second trimesters of pregnancy are inconclusive.
In the general U.S. population, all clinically recognized pregnancies,
regardless of drug exposure, have a background rate of 2-4% for major
malformations, and 15-20% for pregnancy loss.
Based
on animal data, prostaglandins have been shown to have an important role in
endometrial vascular permeability, blastocyst implantation, and
decidualization. In animal studies, administration of prostaglandin synthesis
inhibitors such as aspirin, resulted in increased pre- and post-implantation
loss. Prostaglandins also have been shown to have an important role in fetal
kidney development. In published animal studies, prostaglandin synthesis
inhibitors have been reported to impair kidney development when administered at
clinically relevant doses.
Clinical
Considerations
Fetal/Neonatal Adverse Reactions
Premature
Closure of Fetal Ductus Arteriosus:
Avoid
use of NSAIDs in women at about 30 weeks gestation and later in pregnancy,
because NSAIDs, including Fiorinal, can cause premature closure of the fetal
ductus arteriosus [see WARNINGS; Fetal Toxicity].
Oligohydramnios/Neonatal Renal Impairment
If an
NSAID is necessary at about 20 weeks gestation or later in pregnancy, limit the
use to the lowest effective dose and shortest duration possible. If Fiorinal
treatment extends beyond 48 hours, consider monitoring with ultrasound for
oligohydramnios. If oligohydramnios occurs, discontinue Fiorinal and follow up
according to clinical practice [see WARNINGS; Fetal Toxicity].
Data
Human Data
Premature Closure of Fetal Ductus Arteriosus:
Published
literature reports that the use of NSAIDs at about 30 weeks of gestation and
later in pregnancy may cause premature closure of the fetal ductus arteriosus.
Oligohydramnios/Neonatal Renal Impairment:
Published
studies and post-marketing reports describe maternal NSAID use at about 20
weeks gestation or later in pregnancy associated with fetal renal dysfunction
leading to oligohydramnios, and in some cases, neonatal renal impairment. These
adverse outcomes are seen, on average, after days to weeks of treatment,
although oligohydramnios has been infrequently reported as soon as 48 hours
after NSAID initiation. In many cases, but not all, the decrease in amniotic
fluid was transient and reversible with cessation of the drug. There have been
a limited number of case reports of maternal NSAID use and neonatal renal dysfunction
without oligohydramnios, some of which were irreversible. Some cases of neonatal
renal dysfunction required treatment with invasive procedures, such as exchange
transfusion or dialysis.
Methodological
limitations of these post-marketing studies and reports include lack of a
control group; limited information regarding dose, duration, and timing of drug
exposure; and concomitant use of other medications. These limitations preclude
establishing a reliable estimate of the risk of adverse fetal and neonatal
outcomes with maternal NSAID use. Because the published safety data on neonatal
outcomes involved mostly preterm infants, the generalizability of certain
reported risks to the full-term infant exposed to NSAIDs through maternal use
is uncertain.