Promethazine

Selected oral labels include allergic rhinitis/conjunctivitis, uncomplicated urticaria/angioedema and dermographism; selected transfusion reactions; active/preventive motion sickness; perioperative nausea/vomiting and sedation; and adjunctive postoperative analgesic use. Anaphylaxis use is adjunctive to epinephrine/standard measures after acute symptoms are controlled. Single-ingredient promethazine is not automatically a cough-combination or asthma treatment.

Rectal suppositories provide a separate administration option within their label. Injection is used for selected allergic conditions when oral therapy is not feasible, perioperative/obstetric sedation and nausea/vomiting, postoperative analgesic adjunct and active motion sickness. Hospital parenteral indications do not establish routine home IV administration or oral chronic-insomnia treatment. Reviewed products are prescription NDA/ANDA drugs; no controlled-substance status is inferred from combination products.

Allergy: a usual example is 25 mg at bedtime; alternatives include 12.5 mg before meals/bedtime or 6.25–12.5 mg three times daily, individualized. Motion sickness: 25 mg twice daily, first dose 30–60 minutes before travel, repeat 8–12 hours later if needed. Nausea/vomiting: usual 25 mg; 12.5–25 mg may repeat every 4–6 hours as needed. Adult nighttime/presurgical/obstetric sedation examples are 25–50 mg; use only under an appropriate clinical plan, not routine OTC sleep treatment. Perioperative combinations require reduced companion-depressant doses.

Selected oral liquid is 6.25 mg/5 mL (1.25 mg/mL): 6.25 mg = 5 mL, 12.5 mg = 10 mL, 25 mg = 20 mL. Measure with a calibrated oral device; do not inject. Selected rectal suppositories are 12.5 or 25 mg and are for rectal use only. Their label gives adult motion-sickness 25 mg twice daily and nausea/vomiting 12.5–25 mg every 4–6 hours as needed. The suppository label’s allergy paragraph says “oral dose”; do not turn that route mismatch into an inferred rectal allergy regimen or advise swallowing a suppository.

Under two years is contraindicated at every reviewed route; weight-based dosing does not eliminate fatal respiratory risk. At age two or older use the lowest effective dose, avoid concurrent respiratory depressants and do not treat uncomplicated/unknown-cause vomiting. Oral/rectal labels give selected motion-sickness 12.5–25 mg twice daily and nausea/vomiting 0.5 mg per pound, individualized by age/weight/illness; these are not a universal self-treatment schedule. Injection label says no more than half the suggested adult dose and gives a premedication example 1.1 mg/kg with clinician-managed reduced companions. No pediatric home sedation or automatic repeat-frequency/max algorithm is inferred.

Deep IM is preferred. Selected injection adult examples: allergy 25 mg, repeat within two hours if needed then move to oral treatment as feasible; nausea/vomiting 12.5–25 mg no more frequently than every four hours; hospital sedation 25–50 mg. Pre/postoperative 25–50 mg requires reduced companion depressants. Labor-specific label permits 25–75 mg with reduced analgesic as appropriate, with MAXIMUM 100 mg/24 hours for patients in labor. This labor ceiling is not a universal maximum for every route or indication.

IV use requires dilution in 0.9% sodium chloride ONLY and infusion via a patent catheter in a large vein, preferably central; do not use hand/wrist veins, mix with other drugs or give an undiluted IV push. Concentrations above 1 mg/mL, intra-arterial and subcutaneous administration are contraindicated. The selected current adult Phenergan table specifies 12.5, 25 or 50 mg in 50 mL at at most 2.5 mL/min, and 75 mg in 100 mL at at most 5 mL/min; infuse over 20–40 minutes. The 1 mg/mL figure is a ceiling, not the target concentration for every dose. Stop immediately for site pain and evaluate arterial injection/extravasation.

For eligible patients age two and older, determine the clinical dose first. Selected Phenergan pediatric table uses up to 25 mg in 25 mL saline, or 25–50 mg in 50 mL; maximum 1 mg/mL and 1.25 mL/min. The overlapping 25 mg table wording is not permission to use the higher concentration or a faster adult rate. Use the required large-vein access, close observation and product/hospital protocol. Selected diluted solution may be stored up to four hours at 20–25°C or 24 hours refrigerated 2–8°C. Confirm actual product instructions; another manufacturer’s rate is not automatically interchangeable.

All reviewed routes contraindicate age under two, coma and hypersensitivity/idiosyncratic reaction to promethazine or other phenothiazines. Oral/rectal labels also prohibit antihistamine treatment of lower-respiratory symptoms including asthma. Injection additionally prohibits IV concentration above 1 mg/mL, intra-arterial and subcutaneous routes. Distinguish treating asthma symptoms from the broader precaution to avoid use in respiratory compromise.

Oral tablets, solution and rectal suppositories carry the pediatric fatal-respiratory-depression boxed warning: do not use under two, and exercise caution above that age. Injection’s box additionally warns about severe tissue injury/gangrene and specifies route/concentration restrictions. Neither a calculated mg/kg dose nor a diluted IV preparation guarantees safety.

Drowsiness is prominent; other effects include dizziness, blurred vision, dry mouth, confusion, BP/pulse changes and photosensitivity. Extrapyramidal symptoms or paradoxical agitation/hallucinations can occur, including in children. Serious reports include respiratory depression/apnea, NMS, blood-cell disorders, jaundice and hypersensitivity; injections add local vascular/nerve damage, thrombosis, necrosis and gangrene. No common incidence is extrapolated across all routes.

Avoid or clinically reduce interacting alcohol, opioids, barbiturates, anesthetics and other sedatives. Labels specify that clinician-managed barbiturate doses may need at least half reduction and opioids one-quarter to one-half reduction, individualized. Those historical label proportions are not a safe self-adjustment algorithm; children should avoid concomitant respiratory depressants.

Other anticholinergic drugs add risks in susceptible glaucoma/urinary or GI-obstruction patients. MAO-inhibitor/phenothiazine combinations have reported increased extrapyramidal effects and need clinical review. Do not invent a universal MAOI washout or assume a routine antiemetic is harmless with all psychiatric drugs.

Do not use epinephrine to treat hypotension from promethazine overdose because its vasopressor effect may reverse; this is distinct from epinephrine’s standard role in anaphylaxis, where promethazine is only adjunctive afterward. Some immunologic pregnancy tests may be falsely positive/negative and glucose-tolerance results may change; inform the testing team.

Never use under two. Above that age, lowest effective doses and careful respiratory assessment remain necessary; dehydration can increase dystonia susceptibility, and unexplained vomiting can conceal serious disease. Older patients can develop confusion/oversedation and should generally start at lower doses with close observation, considering organ function and other drugs. Age alone does not establish a universally safe schedule.

Use cautiously with liver dysfunction and cardiovascular disease; consider renal/hepatic/cardiac reserve and polypharmacy in older adults. No numerical eGFR/Child-Pugh adjustment or dialysis supplement appears in these selected labels. Avoid compromised respiratory function such as COPD/sleep apnea; absence of a renal table does not remove respiratory or sedation risk.

Controlled pregnancy data are inadequate; use only when expected benefit justifies fetal risk. Old pregnancy letter-category wording is not proof of safety. Exposure within two weeks of delivery may inhibit newborn platelet aggregation. Labeled obstetric use requires specialist-managed doses and reduced companion analgesic/depressant exposure, not routine home treatment; long-term infant development effects are unknown.

Selected labels state milk excretion is unknown and advise deciding between drug/feeding discontinuation based on maternal treatment importance because serious infant reactions are possible. This focused label-based profile does not establish lactation compatibility, infant dose or a universal pump-and-discard interval; discuss alternatives and the actual maternal/infant circumstances.

Promethazine is a phenothiazine H1 antagonist with anticholinergic and sedating effects; dopamine-antagonist activity is weaker than typical antipsychotic phenothiazines. It does not prevent histamine release or replace emergency anaphylaxis treatment. Mechanism alone does not establish an asthma, cough-combination or long-term psychiatric indication.

Oral effects generally appear around 20 minutes and last 4–6 hours, sometimes 12. Injection label describes effects within about five minutes IV and 20 minutes IM; this is not permission for rapid undiluted IV push. It is metabolized in the liver, with sulfoxide/N-demethyl metabolites appearing in urine; IV half-life in healthy volunteers was 9–16 hours. A clinical effect lasting fewer hours does not justify faster redosing or prove complete clearance.

Rectal dose availability does not establish equal absorption to oral/IV in every patient. The selected suppository clinical-pharmacology text largely repeats oral information; no precise rectal bioavailability/half-life is inferred. Oral solution’s 1.25 mg/mL drug concentration differs from the maximum 1 mg/mL diluted IV restriction; oral excipients make it unsuitable for injection.

Assess alertness, breathing, BP, seizure history, anticholinergic vulnerability, liver/cardiac disease and all depressant drugs. Monitor therapeutic response, excess sedation, involuntary movements, fever/rigidity and breathing difficulty. Injection requires inspection, patent appropriate access, continuous clinical vigilance for tissue injury and strict preparation/rate checks. No universal routine laboratory interval is invented.

Avoid alcohol and driving/hazardous activity until effects are known. Do not share, independently combine with opioids/sedatives or use for unknown-cause child vomiting. Breathing difficulty, unresponsiveness, severe abnormal movements or fever/rigidity needs urgent care. Report injection-site burning/pain immediately; do not wait for visible necrosis. Photosensitivity counseling includes avoiding prolonged sun exposure.

For liquid, confirm 6.25 mg/5 mL and prescribed mL using a calibrated device. Suppositories are rectal only and selected storage is refrigerated. Injectable 25/50 mg/mL stock is NOT ready for IV infusion and must follow the exact manufacturer preparation. Inspect for color/particles and discard abnormal solution; institutional administration safeguards are essential.

Selected Chartwell oral solution is green cherry-scented 6.25 mg/5 mL; 120 mL bottle NDC 62135-774-41, contains 7% alcohol and sucrose. Selected Camber 25 mg rectal suppository is white/off-white bullet-shaped, 12-count NDC 31722-041-31. Selected Phenergan 25 mg/mL stock is a clear colorless 1 mL vial; 25-count NDC 0641-6084-25. Appearance/NDC is manufacturer-specific and does not authenticate an unknown product.

Reviewed oral tablet labeling includes 12.5/25/50 mg promethazine hydrochloride strengths; selected repackaged tablet is 25 mg. Oral solution is 6.25 mg/5 mL. Selected rectal suppositories are 12.5/25 mg. Injection stock is 25 or 50 mg/mL, requiring dilution for permitted IV use. Promethazine-codeine, promethazine-DM and other combinations have separate ingredients/labels and are outside this profile.

Selected oral solution: 20–25°C, tightly closed, protected from light; dispense in a tight light-resistant container. Selected rectal suppositories: refrigerate 2–8°C in a well-closed container. Phenergan injection: 20–25°C, protect from light in carton until use; reject discoloration/particles and follow diluted-solution limits separately. Tablet storage must follow the actual dispensed package; the selected repackaged text does not provide a complete manufacturer-specific storage statement. Keep every form away from children.