Adult Dosing
Allergic conditions
- 6.25-12.5 mg PO tid; may give additional 25 mg PO qhs
Motion sickness
- 25 mg PO bid
- Start 25 mg PO 30-60 mins prior to departure, then q8-12 hrs PRN
Nausea/vomiting
- 12.5-25 mg PO q4-6 hrs
- Max: 50 mg/dose
Prophylaxis of nausea and vomiting
Sedation
- 25-50 mg PO x1
- Max: 50 mg/dose
Pre and postoperative use
- 50 mg PO x1 night before surgery
Postoperative sedation and adjunctive use with analgesics
Pediatric Dosing
Allergic conditions
- >2 yrs
- 6.25-12.5 mg PO tid; may give additional 25 mg PO qhs
- Max: 12.5 mg/dose during day, 25 mg/dose qhs
Nausea/vomiting
- >2 yrs
- 0.5 mg/lb of body weight
- Max: 25 mg/dose
Motion sickness
- >2 yrs
- 12.5-25 mg PO BID
- Max: 25 mg/dose
Sedation
- >2 yrs
- 12.5-25 mg PO X 1
- Max: 25 mg/dose
See Supplemental Patient Information
- Avoid use in pediatric patients <2 yrs of age as potential for fatal respiratory depression exists [US Black Box Warning]
- Respiratory depression, including fatalities may occur with use of this drug in pediatric patients <2 yrs of age. Wide variation in weight based doses is contributing factor for such events [US Black Box Warning]
- Use lowest effective dose in pediatric patients
2 yrs and avoid concomitant use with other respiratory depressant drugs [US Black Box Warning] - Exercise caution while administering this drug to pediatric patients of 2 yrs of age [US Black Box Warning]
- This drug is associated with impairment of mental and/or physical abilities required for the performance of potentially hazardous tasks, such as driving a vehicle or operating machinery. Concomitant use with other CNS depressants amplifies such impairment. Eliminate such agents or administer in reduced dosage in the presence of promethazine hydrochloride
- Potentially fatal respiratory depression may occur. Avoid usage in patients with compromised respiratory function (e.g., COPD, sleep apnea)
- This drug is associated with lowering of seizure threshold
- Potential for occurrence of leukopenia and agranulocytosis exists usually when promethazine hydrochloride is used in association with other known marrow-toxic agents
- A potentially fatal symptom complex sometimes referred to as neuroleptic malignant syndrome (NMS) has occurred in association with administration of antipsychotic drugs. Manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status, and evidence of autonomic instability. Additional signs including elevated creatinine phosphokinase, myoglobinuria (rhabdomyolysis), and acute renal failure have occurred
- Immediately discontinue antipsychotic drugs and other drugs not essential for concomitant therapy, provide intensive symptomatic treatment, carefully monitor patients and provide treatment for concomitant serious medical problems for management of NMS
- Carefully consider potential reintroduction of drug therapy in patients recovered from NMS as recurrences of NMS can occur
- Antiemetic agents are not recommended for therapy of uncomplicated vomiting in pediatric patients, and limit their use to prolonged vomiting of known etiology
- Avoid the use of promethazine hydrochloride in pediatric patients having signs and symptoms suggesting Reye’s syndrome or other hepatic diseases
- Excessively high doses in pediatric patients may lead to sudden death. Hallucinations and convulsions may occur with therapeutic doses and overdoses of promethazine hydrochloride in pediatric patients. Pediatric patients who are acutely ill, associated with dehydration are at increased susceptibility for occurrence of dystonias
- Cholestatic jaundice is associated with usage of this drug
Cautions: Use cautiously in
- Hepatic impairment
- Cardiovascular disease
- COPD
- Asthma
- Seizure disorders
- Lowered seizure threshold
- Bone-marrow depression
- Narrow angle glaucoma
- Prostatic hypertrophy
- Stenosing peptic ulcer
- Pyloroduodenal obstruction
- GI obstruction
- GU obstruction
- Bladder neck obstruction
- IV administration
- Hypersensitivity to sulfites
- Use of CNS depressant
- Pediatric
- Geriatric
Supplemental Patient Information
- Advise patients to avoid engaging in activities requiring mental alertness such as operating a hazardous machinery or driving an automobile
- Avoid prolonged exposure to the sun
- Advise patients to report any involuntary muscle movements
Pregnancy Category:C
Breastfeeding: Possibly unsafe; however occasional short term use of promethazine would pose little risk to the breastfed infant. It may interfere with lactation if given in the early postpartum period. Other less potent antihistamines are preferred. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 15 April 2011). According to manufacturer's data, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
US Trade Name(s)
US Availability
promethazine (generic)
- TABS: 12.5, 25, 50 mg
- SYRUP: 6.25 mg/5 mL
Canadian Trade Name(s)
Canadian Availability
promethazine (generic)
Histantil
UK Trade Name(s)
UK Availability
Avomine
Phenargan
- TABS: 10, 25 mg
- ELIXIR: 5 mg/5 mL
Sominex
Australian Trade Name(s)
- Gold Cross antihistamine elixir
- Phenargan
- Fenezal
- Avomine
Australian Availability
Gold Cross antihistamine elixir
Phenargan
- TABS: 10, 25 mg
- ELIXIR: 5 mg/5 mL
Fenezal
Avomine
Pricing data from www.DrugStore.com in U.S.A.
- Promethazine HCl 6.25 MG/5ML SYRP [Bottle] (HI-TECH)
118 5ml = $12.99
354 5ml = $22.97 - Promethazine HCl 50 MG TABS [Bottle] (ZYDUS PHARMACEUTICALS (USA))
30 mg = $21.99
90 mg = $59.97 - Promethazine HCl 25 MG TABS [Bottle] (ZYDUS PHARMACEUTICALS (USA))
30 mg = $21.99
90 mg = $43.97 - Promethazine HCl 12.5 MG TABS [Bottle] (ZYDUS PHARMACEUTICALS (USA))
30 mg = $15.99
90 mg = $39.97
Warning: This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit drugstore.com.