Promethazine Hydrochloride Tablets

Promethazine is a phenothiazine derivative and an antihistamine that can be used for antiemetic, anti-vertigo, motion sickness, and sedative-hypnotic effects. 1. Antihistamine effect: It competes with histamine released by tissues for H1 receptors, can antagonize the contraction or contracture of histamine on the gastrointestinal tract, trachea, bronchi or bronchiolar smooth muscle, and can relieve the spasmodic and congestive effects of histamine on bronchial smooth muscle. 2. Antiemetic effect: It may be related to the inhibition of the emetic chemoreceptor area of the medulla oblongata. 3. Anti-motion sickness effect: It may act on the vestibular and vomiting centers and midbrain medullary receptors through central anticholinergic properties, mainly blocking the excitation of labyrinthine impulses of cholinergic synapses in the vestibular nucleus. 4. Sedative-hypnotic effect: The mechanism of inhibition of the central nervous system has not yet been clearly elucidated, and it may be due to indirectly reducing the excitability of the brainstem reticular formation activation system.

Main ingredients: The chemical name of this product is: N,N,?-trimethyl-10H-phenothiazine-10-ethylamine hydrochloride. Molecular formula: C17H20N2S·HCl, molecular weight: 320.89

This product is a sugar-coated tablet, which appears white or slightly yellow after removing the sugar coating.

Indications: 1. Skin and mucous membrane allergies: Suitable for long-term and seasonal allergic rhinitis, vasomotor rhinitis, allergic conjunctivitis, urticaria, food allergies, and skin scratches. 2. Motion sickness: carsickness, seasickness, and airplane sickness. 3. Nausea and vomiting.

1. Take the medicine early when used to prevent motion sickness. 2. Reduce the dosage when dehydrated or oliguria occurs to avoid toxic reactions. 3. When taken orally, it can be taken with food or milk to reduce irritation to the gastric mucosa. 4. Common dosage for adults: Oral: ① Anti-allergic, 12.5 mg (0.5 tablet) once, 4 times a day, after meals and before bedtime, 25 mg (1 tablet) before bedtime if necessary; ② Antiemetic, 25 mg (1 tablet) once at the beginning, 12.5-25 mg (0.5-1 tablet) every 4-6 hours if necessary; ③ Anti-vertigo, 25 mg (1 tablet) once, 2 times a day if necessary; ④ Sedative and hypnotic, 25-50 mg (1-2 tablets) once, double if necessary. 5. Common dosage for children: Oral: ① Anti-allergic, 0.125 mg/kg per body weight or 3.75 mg/m2 per body surface area, once every 4 to 6 hours, or 0.25 to 0.5 mg/kg per body weight or 7.5 to 15 mg/m2 per body surface area before bedtime; calculated by age, daily dose for children under 1 year old: 5 to 10 mg, 1 to 5 years old: 5 to 15 mg, 6 years old and above: 10 to 25 mg, can be given once or twice; ② Antiemetic, according to body weight 0.25-0.5 mg/kg or 7.5-15 mg/m2 per body surface area; if necessary, give the drug once every 4-6 hours; ③ Anti-vertigo, 0.25-0.5 mg/kg per body weight or 7.5-15 mg/m2 per body surface area; if necessary, give the drug once every 12 hours, or 12.5-25 mg, twice a day; ④ Sedative and hypnotic, if necessary, 0.5-1 mg/Kg per body weight or 15-30 mg/m2 per body surface area.

Promethazine is a phenothiazine derivative. It has no obvious side effects at low doses, but common side effects of thiazides may occur when used in large quantities and for long periods of time. 1. Increased sensitivity of the skin to light, nightmares, excitability, agitation, hallucinations, toxic delirium, and children are prone to extrapyramidal reactions. The incidence of the above reactions is not high. 2. Symptoms and signs of overdose include: clumsy or odd movements of hands and feet, drowsiness or flushing, fever, shortness of breath or difficulty breathing, increased heart rate (antimuscarinic (M) receptor effect), muscle spasms, especially in the muscles of the neck and back. Restlessness, difficulty walking, spasmodic twitching of the head and facial muscles, or tremors in both hands (the latter is an extrapyramidal effect). 3. Attention should be paid to the following conditions if they persist: the more common ones are drowsiness; the less common ones are blurred vision or color blindness (mild), dizziness, dry mouth, nose and throat, tinnitus, rash, stomach pain or stomach discomfort, slow reaction (more common in children), nausea or vomiting [when undergoing surgery and/or taking other drugs], and even jaundice. Rectal burning or stinging may occur when using suppositories. 4. Cardiovascular adverse reactions are rare, and blood pressure may increase, and occasionally slightly decrease. Leukopenia, granulocytopenia and aplastic anemia are rare.

It is contraindicated for newborns and premature infants.

Precautions for children: Children under 3 months old may not have enough drug metabolizing enzymes in their bodies, so this product should not be used. In addition, it may cause renal insufficiency. Newborns or premature infants, children with acute illness or dehydration, and children with acute infection are prone to dystonia after injection of promethazine. When children take 75-125 mg orally at one time, they may experience abnormalities such as overexcitement, irritability, or (and) nightmares. Precautions for pregnancy and lactation: 1. After women take this drug, it can induce jaundice and extrapyramidal symptoms in infants. Therefore, pregnant women should stop using this drug 1-2 weeks before delivery. 2. General antihistamines are more dangerous to infants, especially newborns and premature infants. Lactating women need to weigh the pros and cons when using this product. Precautions for the elderly: The elderly are prone to dizziness, sluggishness, mental confusion and hypotension when using this drug. The elderly are also prone to extrapyramidal symptoms, inability to sit still (akathisia) and persistent movement disorders when using this drug, which are more likely to occur when the dosage is large or the drug is administered parenterally.

1. When ethanol or other central nervous system depressants, especially anesthetics, barbiturates, monoamine oxidase inhibitors or tricyclic antidepressants are used together with this product, the effects of promethazine or (and) these drugs may be enhanced, and the dosage should be adjusted separately. 2. When anticholinergic drugs, especially atropine drugs, are used together with promethazine, the antimuscarinic effect of the latter is enhanced. 3. When antihypertensive drugs such as brombenzylamine, isoquine or guanethidine are used together with promethazine, the antihypertensive effect of the former is enhanced. When epinephrine is used together with promethazine, the α effect of epinephrine can be blocked, and the β effect becomes dominant. 4. When ototoxic drugs such as cisplatin, paromomycin and other aminoglycoside antibiotics, salicylic acid preparations and vancomycin are used together with promethazine, their ototoxic symptoms can be masked.

Keep away from light and sealed.

25 mg

36 months.