Promethazine (promethazine HCl)

Dosages of promethazine hydrochloride by the various routes of administration are identical; dosage is expressed in terms of the hydrochloride salt.

Dosages of promethazine hydrochloride by the various routes of administration are identical.

Because of the risk of potentially fatal respiratory depression, promethazine hydrochloride should not be used in children younger than 2 years of age. The drug should be used cautiously and at the lowest effective dosage in older children (See Cautions: Pediatric Precautions.)

Promethazine hydrochloride is administered orally, rectally, or by deep IM injection. The drug can also be administered by IV infusion (after dilution); however, IM injection is preferred because IV administration has been associated with severe tissue injury, including gangrene requiring amputation.

Subcutaneous or intra-arterial injection of promethazine hydrochloride is contraindicated.

Promethazine hydrochloride tablets should be stored at 20-25degreesC in a tight, light-resistant container; the oral syrup should be stored at 25degreesC (excursions permitted from 15-30degreesC) in tightly closed containers protected from light) and the oral solution should be stored at 20-25degreesC in tight, light-resistant containers protected from light. The rectal suppositories should be stored in well-closed containers at 2-8degreesC.

Promethazine hydrochloride injection should be stored at 20-25degreesC; protect from light. The diluted solution may be stored for up to 4 hours at room temperature (20-25degreesC), or for up to 24 hours refrigerated (2-8degreesC).

Promethazine hydrochloride may be administered orally, rectally, or by deep IM injection. Promethazine hydrochloride also is administered by IV injection. However, because IV administration of the drug has been associated with severe tissue injury, including gangrene requiring amputation, the US Food and Drug Administration (FDA) states that deep IM injection is the preferred method for administration of promethazine hydrochloride injections. (See Cautions: Precautions and Contraindications.) If IV administration of promethazine hydrochloride is required, FDA states that the drug should be administered through the tubing of an IV infusion set that is known to be correctly functioning; FDA also states that the maximum rate of IV administration is 25 mg/minute, and the maximum concentration of the injection is 25 mg/mL. If the patient complains of pain at the injection site during presumed IV injection of the drug, the injection should immediately be stopped, and the possibility of intra-arterial placement of the needle or perivascular extravasation should be evaluated. Promethazine hydrochloride injection is commercially available in 2 strengths: 25 mg/mL and 50 mg/mL. FDA states that the preparation containing 50 mg/mL is for IM injection only; the preparation containing 25 mg/mL may be administered by IM or IV injection.

Because of the risk of severe tissue injury and amputations if promethazine hydrochloride is inadvertently administered intra-arterially or if extravasation were to occur, some medication safety experts (e.g., the Institute for Safe Medication Practices (ISMP)) recommend that parenteral administration of the drug be avoided and replaced by safer alternative therapies.

Promethazine hydrochloride injection should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit. The injection should be discarded if the solution is discolored or contains a precipitate.

No dosing information is available for this tab.

No dosing information is available for this tab.

There is no enhanced messaging for this drug.

There are no contraindication interactions for this drug.

There are no severe interactions for this drug.

There are no moderate interactions for this drug.

*Pediatric patients <2 years of age.

*Patients in comatose states.

*Patients with known hypersensitivity or history of idiosyncratic reaction to promethazine or to other phenothiazines.

*Treatment of lower respiratory tract symptoms including asthma.

*IV administration at concentrations greater than 1 mg/mL due to the risk of perivascular extravasation, unintentional intra-arterial injection, and intraneuronal or perineuronal infiltration.

*Use of promethazine hydrochloride injection as an intra-arterial injection due to the likelihood of severe arteriospasm and the possibility of resultant gangrene.

*Use of promethazine hydrochloride injection as a subcutaneous injection because chemical irritation and necrotic lesions have been reported.

There are no contraindication contraindications for this drug.

There are no severe contraindications for this drug.

There are no moderate contraindications for this drug.

Drowsiness is the most prominent CNS effect of promethazine.

There are no severe adverse reactions for this drug.

There are no less severe adverse reactions for this drug.

No enhanced messaging available.

Because respiratory depression (sometimes fatal) has been reported in pediatric patients younger than 2 years of age receiving a wide range of weight-adjusted doses of promethazine during postmarketing surveillance, the drug is contraindicated in pediatric patients younger than 2 years of age. Promethazine should be administered with caution in children 2 years of age and older because of the risk of potentially fatal respiratory depression. The lowest effective dose of the drug should be used. Concomitant use of promethazine with other respiratory depressant drugs should be avoided. Antiemetics are not recommended for the treatment of uncomplicated vomiting in pediatric patients. The drug should not be used in acutely ill or dehydrated children, since these patients have an increased susceptibility to dystonias. Use of promethazine also should be avoided in children with signs and symptoms that suggest Reye's syndrome, since the potential extrapyramidal effects produced by the drug may obscure the diagnosis of or be confused with the CNS signs and symptoms of this condition, and in children with signs and symptoms of other hepatic disease. Excessively high dosages of promethazine have caused sudden death in pediatric patients, although sleep apnea and sudden infant death syndrome (SIDS) have been reported in a number of infants and young children who were receiving usual dosages of promethazine. The relationship to the drugs and possible mechanism(s) of such effects have not been elucidated. In one study, the number, but not the duration, of central apneas during sleep was increased and obstructive apnea during sleep (accompanied by decreased heart rate and arterial oxygen pressure) developed in 4 healthy infants who were receiving 1 mg/kg of promethazine hydrochloride daily for 3 days. Promethazine should be avoided in children with a history of sleep apnea, those with a family history of SIDS, and those who are less prone than usual to spontaneous arousal from sleep.

Safe use of promethazine during pregnancy (except during labor) with respect to possible adverse effects on fetal development has not been established. Although there are no adequate and controlled studies to date in humans, promethazine has not been shown to be teratogenic in rats receiving oral dosages of 6.25-12.5 mg/kg daily (about 2.1-4.2 times the maximum recommended human dosage, depending on the use of the drug). The drug has been shown to produce fetal mortality in rats receiving intraperitoneal dosages of 25 mg/kg daily. Antihistamines, including promethazine, have been fetocidal in rodents, but the pharmacologic effects of histamine in rodents differ from those in humans. Promethazine should be used during pregnancy only when the potential benefits justify the possible risks to the fetus.

Safe use of promethazine during pregnancy (except during labor) with respect to possible adverse effects on fetal development has not been established. Although there are no adequate and controlled studies to date in humans, promethazine has not been shown to be teratogenic in rats receiving oral dosages of 6.25-12.5 mg/kg daily (about 2.1-4.2 times the maximum recommended human dosage, depending on the use of the drug). The drug has been shown to produce fetal mortality in rats receiving intraperitoneal dosages of 25 mg/kg daily. Antihistamines, including promethazine, have been fetocidal in rodents, but the pharmacologic effects of histamine in rodents differ from those in humans. Promethazine has been reported to possibly ameliorate the effects of hemolytic disease of the newborn+ (erythroblastosis fetalis) when administered during pregnancy in Rh-sensitized women, but the safety and efficacy of the drug for this use have not been clearly established; other methods of management are preferred. Promethazine should be used during pregnancy only when the potential benefits justify the possible risks to the fetus.

It is not known whether promethazine is distributed into human milk. Because many drugs are distributed in human milk and because of the potential for serious adverse reactions to promethazine in nursing infants if it were distributed, a decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the woman.

It is not known whether promethazine is distributed into milk. Because many drugs are distributed in human milk and because of the potential for serious adverse reactions to promethazine in nursing infants if it were distributed, a decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the woman.

Select dosage with caution, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy; monitor patients closely.

Clinical studies of promethazine did not include sufficient numbers of patients 65 years of age and older to determine whether geriatric patients respond differently than younger patients. Although clinical experience generally has not revealed age-related differences in response to the drug, care should be taken in dosage selection of promethazine. Risk of sedative effects and confusion associated with promethazine is increased in geriatric patients.