Dosage of Rapifen in details
The dosage of Rapifen should be individualized according to age, body weight, physical status, underlying pathological condition, use of other drugs and type of surgery and anaesthesia.
The initial dose should be reduced in the elderly and in debilitated patients. In children, it should be increased. The effect of the initial dose should be taken into account in determining supplemental doses.
To avoid bradycardia, it is recommended to administer a small IV dose of an anticholinergic agent just before induction. Droperidol may be given to prevent nausea and vomiting.
For Use as an Induction Agent: An IV bolus dose of ≥120 mcg/kg (17 mL/70 kg) Rapifen will induce hypnosis and analgesia while maintaining good cardiovascular stability in patients with adequate muscle relaxation.
For Short Procedures and Use in Outpatients: Small doses of Rapifen are most useful for minor, short but painful surgical procedures and for outpatients, provided good monitoring equipment is available.
An IV bolus dose of 7-15 mcg/kg (1-2 mL/70 kg) will suffice for procedures lasting <10 min. Should the duration of the procedure exceed 10 min, further increments of 7-15 mcg/kg (1-2 mL/70 kg) should be given 10-15 min or as required.
Spontaneous respiration may be maintained in most instances with a dose of 7 mcg/kg (1 mL/70 kg) or less, slowly injected; suggested increments with this technique are 3.5 mcg/kg (0.5 mL/70 kg).
It is preferable not to administer droperidol or benzodiazepines to outpatients as these drugs may lengthen the recovery period. In outpatients, a preferred technique consists of an anticholinergic agent, a short-acting induction hypnotic, Rapifen and N2O/O2.
When postoperative nausea occurs, it is of relatively short duration and easily controlled by conventional measures.
For Procedures of Medium Duration: The dose of initial IV bolus should be adapted to the expected duration of the surgical procedure as follows. See Table 1.
When surgery is more prolonged or more aggressive, analgesia can be maintained by either increments of 15 mcg/kg (2 mL/70 kg) Rapifen when required (to avoid postoperative respiratory depression, no Rapifen should be administered during the last 10 min of surgery; or a Rapifen infusion at a rate of 1 mcg/kg/min (0.14 mL/70 kg/min) until 5-10 min before the completion of surgery.
Periods of very painful stimuli can easily be overcome by a small dose increments or by temporarily increasing the infusion rate. When Rapifen is used without N2O/O2 or another inhalation anaesthetic, a higher maintenance dose of Rapifen is required.
For Long Procedures: Rapifen may be used as the analgesic component of anaesthesia for long lasting surgical procedures especially when rapid extubation is indicated. Optimum analgesia and stable autonomic condition are maintained through an individually adapted initial IV dose and by adjusting the infusion rate to the severity of the surgical stimuli and the reactions of the patients.
Rapifen interactions
Drugs Modifying the Effect of Rapifen: Drugs eg, barbiturates, benzodiazepines, neuroleptics, halogenic gases and other, nonselective CNS depressants (eg, alcohol) may potentiate the respiratory depression of narcotics.
When patients have received such drugs, the dose of Rapifen required will be less than usual. Likewise, following the administration of Rapifen, the dose of other CNS-depressant drugs should be reduced.
Rapifen is metabolized mainly via the human cytochrome P-450 3A4 enzyme. In vitro data suggest that potent cytochrome P-450 3A4 enzyme inhibitors (eg, ketoconazole, itraconazole, ritonavir) may inhibit the metabolism of Rapifen. Available human pharmacokinetic data indicate that the metabolism of Rapifen is inhibited by fluconazole, voriconazole, erythromycin, diltiazem and cimetidine (known cytochrome P-450 3A4 enzyme inhibitors). This could increase the risk of prolonged or delayed respiratory depression. The concomitant use of such drugs requires special patient care and observation; in particular, it may be necessary to lower the dose of Rapifen.
It is usually recommended to discontinue MAO inhibitors 2 weeks prior to any surgical or anaesthetic procedure.
Effect of Rapifen on the Metabolism of Other Drugs: In combination with Rapifen, the blood concentrations of propofol are 17% higher than in the absence of Rapifen. The concomitant use of Rapifen and propofol may require a lower dose of Rapifen.
Incompatibilities: The injectable solution must not be mixed with other products. If desired, Rapifen may be mixed with sodium chloride or glucose IV infusions. Such dilutions are compatible with plastic infusion sets. These should be used within 24 hrs of preparation.
References
- FDA/SPL Indexing Data. "1N74HM2BS7: The UNique Ingredient Identifier (UNII) is an alphanumeric substance identifier from the joint FDA/USP Substance Registration System (SRS).". https://www.fda.gov/ForIndustry/Data... (accessed September 17, 2018).
- MeSH. "Anesthetics, Intravenous". https://www.ncbi.nlm.nih.gov/mesh/68... (accessed September 17, 2018).
- PubMed Health. "Alfentanil (By injection) (Alfentanil Novaplus): This section provide the link out information of drugs collectetd in PubMed Health. ". http://www.ncbi.nlm.nih.gov/pubmedhe... (accessed September 17, 2018).
Reviews
The results of a survey conducted on ndrugs.com for Rapifen are given in detail below. The results of the survey conducted are based on the impressions and views of the website users and consumers taking Rapifen. We implore you to kindly base your medical condition or therapeutic choices on the result or test conducted by a physician or licensed medical practitioners.User reports
Consumer reported frequency of use
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Information checked by Dr. Sachin Kumar, MD Pharmacology
