WARNINGS
WARNING
PHENERGAN (PROMETHAZINE HCL SUPPOSITORIES SHOULD NOT BE USED
IN PEDIATRIC PATIENTS LESS THAN 2 YEARS OF AGE BECAUSE OF THE POTENTIAL FOR
FATAL RESPIRATORY DEPRESSION.
POSTMARKETING CASES OF RESPIRATORY DEPRESSION, INCLUDING FATALITIES,
HAVE BEEN REPORTED WITH USE OF PROMETHAZINE HCL SUPPOSITORIES IN PEDIATRIC
PATIENTS LESS THAN 2 YEARS OF AGE. A WIDE RANGE OF WEIGHT-BASED DOSES OF PROMETHAZINE
HCL SUPPOSITORIES HAVE RESULTED IN RESPIRATORY DEPRESSION IN THESE PATIENTS.
CAUTION SHOULD BE EXERCISED WHEN ADMINISTERING PROMETHAZINE HCL
TO PEDIATRIC PATIENTS 2 YEARS OF AGE AND OLDER. IT IS RECOMMENDED THAT THE
LOWEST EFFECTIVE DOSE OF PROMETHAZINE HCL BE USED IN PEDIATRIC PATIENTS 2 YEARS
OF AGE AND OLDER AND CONCOMITANT ADMINISTRATION OF OTHER DRUGS WITH RESPIRATORY
DEPRESSANT EFFECTS BE AVOIDED.
CNS Depression
Phenergan (Promethazine HCl) Suppositories may impair the
mental and/or physical abilities required for the performance of potentially
hazardous tasks, such as driving a vehicle or operating machinery. The
impairment may be amplified by concomitant use of other central-nervous-system
depressants such as alcohol, sedatives/ hypnotics (including barbiturates),
narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants,
and tranquilizers; therefore, such agents should either be eliminated or given
in reduced dosage in the presence of promethazine HCl (see PATIENT INFORMATION and DRUG INTERACTIONS).
Respiratory Depression
Phenergan (Promethazine HCl) Suppositories may lead to
potentially fatal respiratory depression.
Use of Phenergan (Promethazine HCl) Suppositories in
patients with compromised respiratory function (e.g., COPD, sleep apnea) should
be avoided.
Lower Seizure Threshold
Phenergan (Promethazine HCl) Suppositories may lower seizure
threshold. It should be used with caution in persons with seizure disorders or
in persons who are using concomitant medications, such as narcotics or local
anesthetics, which may also affect seizure threshold.
Bone-Marrow Depression
Phenergan (Promethazine HCl) Suppositories should be used
with caution in patients with bone-marrow depression. Leukopenia and agranulocytosis
have been reported, usually when promethazine HCl has been used in association
with other known marrow-toxic agents.
Neuroleptic Malignant Syndrome
A potentially fatal symptom complex sometimes referred to as
Neuroleptic Malignant Syndrome (NMS) has been reported in association with
promethazine HCl alone or in combination with antipsychotic drugs. Clinical
manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status
and evidence of autonomic instability (irregular pulse or blood pressure,
tachycardia, diaphoresis and cardiac dysrhythmias).
The diagnostic evaluation of patients with this syndrome is
complicated. In arriving at a diagnosis, it is important to identify cases
where the clinical presentation includes both serious medical illnesses (e.g., pneumonia,
systemic infection, etc.) and untreated or inadequately treated extrapyramidal
signs and symptoms (EPS). Other important considerations in the differential
diagnosis include central anticholinergic toxicity, heat stroke, drug fever and
primary central nervous system (CNS) pathology.
The management of NMS should include 1) immediate
discontinuation of promethazine HCl, antipsychotic drugs, if any, and other
drugs not essential to concurrent therapy, 2) intensive symptomatic treatment
and medical monitoring, and 3) treatment of any concomitant serious medical
problems for which specific treatments are available. There is no general
agreement about specific pharmacological treatment regimens for uncomplicated
NMS.
Since recurrences of NMS have been reported with
phenothiazines, the reintroduction of promethazine HCl should be carefully
considered.
Use In Pediatric Patients
PHENERGAN (PROMETHAZINE HCL) SUPPOSITORIES ARE
CONTRAINDICATED FOR THE USE IN PEDIATRIC PATIENTS LESS THAN TWO YEARS OF AGE.
CAUTION SHOULD BE EXERCISED WHEN ADMINISTERING PHENERGAN (PROMETHAZINE
HCL) SUPPOSITORIES TO PEDIATRIC PATIENTS 2 YEARS OF AGE AND OLDER BECAUSE OF
THE POTENTIAL FOR FATAL RESPIRATORY DEPRESSION. RESPIRATORY DEPRESSION AND
APNEA, SOMETIMES ASSOCIATED WITH DEATH, ARE STRONGLY ASSOCIATED WITH
PROMETHAZINE PRODUCTS AND ARE NOT DIRECTLY RELATED TO INDIVIDUALIZED
WEIGHT-BASED DOSING, WHICH MIGHT OTHERWISE PERMIT SAFE ADMINISTRATION.
CONCOMITANT ADMINISTRATION OF PROMETHAZINE PRODUCTS WITH OTHER RESPIRATORY
DEPRESSANTS HAS AN ASSOCIATION WITH RESPIRATORY DEPRESSION, AND SOMETIMES
DEATH, IN PEDIATRIC PATIENTS.
ANTIEMETICS ARE NOT RECOMMENDED FOR TREATMENT OF
UNCOMPLICATED VOMITING IN PEDIATRIC PATIENTS, AND THEIR USE SHOULD BE LIMITED
TO PROLONGED VOMITING OF KNOWN ETIOLOGY. THE EXTRAPYRAMIDAL SYMPTOMS WHICH CAN
OCCUR SECONDARY TO PHENERGAN (PROMETHAZINE HCL) SUPPOSITORIES ADMINISTRATION
MAY BE CONFUSED WITH THE CNS SIGNS OF UNDIAGNOSED PRIMARY DISEASE, E.G.,
ENCEPHALOPATHY OR REYE'S SYNDROME. THE USE OF PHENERGAN (PROMETHAZINE HCL)
SUPPOSITORIES SHOULD BE AVOIDED IN PEDIATRIC PATIENTS WHOSE SIGNS AND SYMPTOMS
MAY SUGGEST REYE'S SYNDROME OR OTHER HEPATIC DISEASES.
Excessively large dosages of antihistamines, including
Phenergan (Promethazine HCl) Suppositories, in pediatric patients may cause
sudden death (see OVERDOSAGE). Hallucinations and convulsions have occurred
with therapeutic doses and overdoses of promethazine HCl in pediatric patients.
In pediatric patients who are acutely ill associated with dehydration, there is
an increased susceptibility to dystonias with the use of promethazine HCl.
Other Considerations
Administration of promethazine HCl has been associated with
reported cholestatic jaundice.