Butorphanol sodium tartrate (0,2 %solution for injections)
Solutio Butorphanoli tartratis 0,2 % pro injectionibus
International nonproprietary name
Butorphanol.
Butorphanol.
Pharmacotherapeutic group
Narcotic analgesics. The opioids, derivatives of morphine.
Composition of the preparation
1 ml of solution for injections contains 2 mg of butorphanol sodium tartratein 1 ml.
Pharmacological action
Pharmacodynamics
Butorphanol is opiod analgesic, an agonist-antagonist of opiod receptors, derivative of fenantren. Has agonistic action in relation to opiod receptors of kappa class, and it is mixed antagonist of m-opiod receptors. Activates endogenous antinociceptive system mainly through kappa-opiod receptors and thus disturb interneuronic transmission of painful impulses at various levels of the central nervous system, and also changes emotional picture of pain, influencing on the high parts of brain.
It has antitussive and sedative effect besides analgesic action, stimulates the vomiting center, causes narrowing of pupils, influences on hemodynamics (increase systole ABP, pressure in pulmonary artery and intracranial pressure). At controlled application the possibility of addiction development and medicinal (opioid) dependence is very small.
The analgesic effect takes place in several minutes after intravenous introduction, through 10-15 mines after intramuscular introduction. The maximal activity is observed in 30-60 minutes Action of the preparation proceeds for 3-4 h.
Pharmakokinetics
The preparation is quickly absorbed in systemic blood flow from a place of intramuscular injection. The maximal concentration in plasma is achieved in 20-40 minutes. Binding with plasma proteins is 80 %. The preparation passes through hematoencephalic and placental barriers, and also is excreted with breast milk; it is metabolized in a liver. It is eliminated mainly in the form of metabolites with urine (70-80 %) and with feces (15 %); in not changed form - with urine (5 %). The period of half-elimination in young patients is 4,7 h, in elderly patients is 6,6 h, in patients with the expressed kidneys function failure is 10,5 h.
Indications
Butorphanol is applied as anesthetizing agent at the expressed painful syndrome of various origin, in the preoperative, operational and postoperative periods, pains at malignant neoplasms, for anesthesia during labors (at absence of fetal pathology signs in fetus).
Dosage and method of administration
At painful syndrome it is recommended to inject 1 mg intravenously or 2 mg intramuscularly each 3-4 hours as required. In elderly patients, and also in patients with liver and kidneys function failure the dose should be reduced twice, and the interval between injections should be not less than 6 h.
The usual dose administrated for premedication is 2 mg intramuscularly in 60-90 min before operation or 2 mg intravenously directly before the operation.
At carrying out of intravenous narcosis it is necessary to inject 2 mg of butorphanol intravenously before introduction of thiopental sodium, and then 0,5-1,0 mg of the preparation should be added for maintenance of necessary anesthetica depth. The general dose demanded for narcosis is usually from 4 mg to 12,5 mg.
It is recommended during labors to enter 1 mg or 2 mg intramuscularly or intravenously to parturient women with a duration of gestation not less than 37 weeks at absence of fetal pathology signs in fetus. Butorphanol is not necessary to introduce more often than once for four hours, last injection should be made not less than 4 hours before delivery.
Special indications
Butorphanol is necessary to administrate with extra care at respiratory failure, craniocerebral traumas, disorders of liver and kidneys functions, bronchial asthma, diseases of cardiovascular system (acute myocardial infarction, cardiac rhythm disorders, arterial hypertension), in patients elder than 65 years.
During treatment by a preparation it is not recommended to be engaged in the kinds of activity demanding enhanced attention, fast mental and motor reactions.
Side effects
The sleepiness, giddiness, mental confusion, headaches, anxiety, euphoria, nervousness, exaltation, dysphoria, hallucinations,heart rate increase, an arterial hypotension, nausea, vomiting, dryness in mouth, disturbance of visual acuity, disorders of urination, excessive clammy sweat eat, skin itch are possible at application of butorphanol. At long repeated application of butorphanolin high doses the opportunity of medicinal dependence development is not excluded.
Contraindications
Hypersensitivity to butorphanol. The conditions, accompanied the respiratory depression or expressed depression of central nervous system. Convulsive states. The increased intracranial pressure. Traumas of a head. Acute alcoholic conditions and alcoholic psychosis. Acute surgical diseases of organs of abdominal cavity before diagnosis formulation. Age under 18 years. Pregnancy (except for preparation for labors), the period of breast feeding. Medicinal dependence in relation to morphine-like preparations (morphine, promedolm, fentanyl).
It is not necessary to apply butorphanol on background of treatment by monoamine oxidase inhibitors and within 14 days after their canceling.
Interactions with other medicinal preparations
Strengthens suppressive action on the central nervous system of anesthetic drugs, soporifics, sedatives, antihistaminic agents with the central component of action, anxiolytics, antipsychotics and antidepressive preparations. Under careful observation and in the reduced doses it is necessary to apply butorphanol on background of action of anesthetic drugs, soporifics, anxiolytics, antidepressants and neuroleptics in order to prevent excessive deppression of the central nervous system and inhibition of the respiratory center activity. The preparation should not be combined with other narcotic analgesics because of danger of weakening of analgesia and an opportunity of provocation ofwithdrawal syndrome in patients with dependence to opioids.
Overdosage
The most serioussignsof overdosage are the hypoventilation, development of cardiacdecompensation and/or circulatory collapse vascular failure, struporous or coma state.
Treatment:first aid at poisoning - maintenance of sufficient pulmonary ventilation, systemic hemodynamics, normal body temperature. Intravenous introduction of naloxone (narcan), specific opioid antagonist, in a dose from 0,4 to 2 mg is possible at respiratory depression.
The form of release
0,2 % solution for injections in 1 and 2 ml ampoules and in 1 ml syringe-tubes. 5 or 10 ampoules in a blister. 10 ampoules in a box.
1 or 2 syringe-tube in a blister or in a pack.
