Blocker of histamine H1-receptors. Anti-allergic drug.

Pharmacological action

Blocker of histamine H1-receptors, a phenothiazine derivative. It has a pronounced antihistamine activity and has a significant effect on the CNS (sedative, hypnotic, antiemetic, antipsychotic and hypothermic effects). It prevents and calms hiccups.
Prevents histamine-mediated effects (including urticaria and itching). Anticholinergic action causes a drying effect on the mucous membranes of the nose and mouth.
The antiemetic effect of promethazine is due to its central anticholinergic effect, decrease in excitability of the vestibular system, suppression of labyrinthine function and direct inhibitory effect on trigger chemoreceptor zones of medulla oblongata.
The sedative effect is due to inhibition of histamine-K-methyltransferase and blockade of central histamine receptors.
Blockade of other CNS receptors such as serotonin and choline receptors is also possible; stimulation of α-adrenoreceptors indirectly attenuates stimulation of the reticular formation of the brain stem.
Because its chemical structure is different from that of other phenothiazine antipsychotics, promethazine has a weaker antipsychotic effect.
In therapeutic doses it has no effect on the cardiovascular system.
Clinical effects occur 20 min after oral administration (15-60 min on average), 2 min after IUI or 3-5 min after IUI and usually last for 4-6 h (sometimes remaining as long as 12 h).

Pharmacokinetics

Pipolfen (Promethazine) - Instructions for use

After oral administration, it is rapidly and well absorbed from the gastrointestinal tract.
The binding of promethazine to plasma proteins is about 90%.
It penetrates the HEB and the placental barrier.
Intensively metabolized in the liver during “first passage” mainly by S-oxidation.
Promethazine sulfoxides and N-demethyl-promethazine are the main metabolites that are determined in the urine.
It is excreted mainly by the kidneys; to a lesser extent, through the intestines.

Indications for administration of PIPOLFEN®

  • Allergic diseases (including urticaria, serum sickness, hay fever, allergic rhinitis, allergic conjunctivitis, angioedema, pruritus);
  • adjuvant therapy of anaphylactic reactions (after the acute manifestations are stopped by other means, for example, epinephrine /adrenaline/);
  • As a sedative in the pre- and postoperative period;
  • to prevent or relieve nausea and vomiting associated with anesthesia and/or occurring in the postoperative period;
  • Postoperative pain (in combination with analgesics);
  • kinetosis (to prevent and relieve dizziness and nausea during transportation);
  • as a component of lytic mixtures used to potentiate anesthesia in surgical practice (for parenteral use).

Dosage regimen

Pipolfen (Promethazine) - Instructions for use

It is administered orally, intramuscularly and intravenously. Maximal daily dose for adults is 150 mg. Intramuscularly – adults 25 mg once a day, if necessary 12.5-25 mg every 4-6 hours. In treatment of allergic diseases, Pipolfen® is prescribed orally in a dose of 25 mg once a day in the evening or 25 mg twice a day (morning and evening). The drug should be prescribed in the minimum effective dose. For prevention and treatment of nausea and vomiting the drug is prescribed orally or intramuscularly in a single dose of 25 mg. If necessary, 25 mg may be administered every 4-6 hours. As a sedative in surgery on the eve of surgery, it is prescribed orally or intramuscularly in a dose of 25-50 mg once at night. For preoperative preparation 2.5 hours before surgery 50 mg of Pipolfen is administered as part of lytic mixtures, if necessary 1 hour later the administration can be repeated. For anesthesia and analgesia induction during certain diagnostic and surgical interventions such as repeated bronchoscopy, ophthalmologic operations, Pipolfen® can be administered by IV in doses of 0.15-0.3 mg/kg of body weight. In children over 2 months old the drug can be administered 3 to 5 times per day in a dose of 0.5 to 1 mg/kg of body weight. In severe cases the single dose for intravenous injection may be increased to 1-2 mg/kg of body weight. Children aged 6 to 14 years are prescribed orally in dose of 25 mg (1 tablet) 3 to 4 times daily. It is not recommended to divide the tablet tablet in half; therefore, this dosage form is not indicated for children under 6 years of age.

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