Evaluation of phenazocine with meperidine as an analgesic agent during labor, by the double blind method

Parenteral opioids for maternal pain management in labour

“…Four studies described using numbered opaque sealed envelopes to conceal allocation (Giannina 1995; Khooshideh 2009; Tsui 2004; Volikas 2001). Seventeen studies described using identical coded drug boxes (although it may not have been clear who had access to the code or when the code was broken) (Atkinson 1994; Borglin 1971; Campbell 1961; Douma 2010; Fairlie 1999; Gillam 1958; Grant 1970; Lardizabal 1999; Levy 1971; Maduska 1978; Moore 1970; Morley-Forster 2000; Morrison 1987; Olofsson 1996; Olson 1964; Sheikh 1986; Wilson 1986). In the remaining studies it was not clear what steps were taken to conceal allocation at the point of randomisation.…”

“…In addition, even where all women appeared to be accounted for at follow-up, there were frequently missing data for specific outcomes. In some studies loss to follow-up or missing data were greater than 10% (Bitsch 1980; Fairlie 1999; Hamann 1972; Levy 1971; Moore 1970; Mowat 1970; Olson 1964; Wilson 1986), or greater than 20% (De Boer 1987; Frank 1987; Giannina 1995; Gillam 1958; Nicholas 1982; O’Dwyer 1971; Refstad 1980).…”

“…No exclusion criteria specified Interventions Experimental: 0.05 mg/kg IV morphine up to 3 doses (max 0.15 mg/kg body weight)Control: 0.5 mg/kg IV pethidine up to 3 doses (max 1.5 mg/kg body weight) Both groups had continuous FHR monitoring. Outcomes Sedation rates; CS, nausea and vomiting. Notes Risk of bias Bias Authors’ judgement Support for judgement Random sequence generation (selection bias) Unclear risk “assigned at random.” Allocation concealment (selection bias) Low risk Coded ampoules provided by pharmacy. Blinding (performance bias and detection bias)Women Low risk Described as double blind; pharmacy provided identical coded ampoules Blinding (performance bias and detection bias)Clinical staff Low risk Described as double blind; pharmacy provided identical coded ampoules Blinding (performance bias and detection bias)Outcome assessor Unclear risk Unclear. Incomplete outcome data (attrition bias)All outcomes Low risk No apparent loss to follow-up. Selective reporting (reporting bias) Unclear risk Unclear. Other bias Unclear risk Small sample and no clear information that groups were comparable at baseline. Range of cervical dilations at recruitment between 4 and 9 cm Olson 1964…”

A Comparison Between Pethidine and Phenazocine (Narphen) for Relief of Pain in Labour

“…Our routine dose of pethidine given in labour is 150 mg. A dose of 3 mg. of phenazocine was chosen for comparison. This dose, chosen in consultation with the drug manufacturers and based on the previous study of Olson and Riva (1964) was estimated to produce a similar analgesic effect to 150 mg. pethidine. A larger dose was rejected because of the possible risk of fetal depression.…”

“…(1961), described phenazocine as being four times as potent as morphine. Several trials of phenazocine in labour have suggested that it is as effective an analgesic as pethidine but with a lower incidence of side effects (Olson and Riva, 1964;Corbit and First, 1961 ;Mitchell, 1960;Sadove et al, 1960).…”