The Effect of IV PAPAVERINE 80 mg Prior to Catheter Balloon Insertion on Bishop Score and Pain, Double Blinded Randomized Placebo Controlled Trial

There are different methods of induction of labor, the choice of the best method for that patient depends on the bishop score, an estimate that is based on data related to the cervix such as opening, effacement and other parameters, also the choice of the method of induction depends on the obstetric history of the patient. A Bishop score less than 6 indicates an unriped cervix, therefore increasing the chance of labor induction failure,methods have been developed to ripen the cervix; among the methods are catheter balloon insertion and prostaglandins. The mechanisms by which the catheter works include a mechanical effect and indirect effect on local secretion of prostaglandins.

The cervix consists of connective tissue, smooth muscle, and parasympathetic innervation. Smooth muscle makes up about 15% of the cervix, is mainly found under the internal opening of the neck. Papaverine and its derivatives are musculotropic antispasmodic drugs that directly affect smooth muscle, the mechanism is to reduce the spasm of smooth muscle resulting in relaxation. Studies on the pharmacokinetics of this drug show that it has a half-life of 0.5-2 hours and its effect is apparent within 10 minutes.

Administration of antispasmodic drugs during childbirth is common in developing and developed countries. Based on previous studies, the use of these drugs during childbirth may lead to a faster opening of the cervix. Possible uses of Papaverine include, administered separately or in combination with other treatments such as rupture of amniotic membranes and/or Oxytocin administration. According to some studies, administration of Papaverine at birth can be used as a preventive or therapeutic strategy in cases of prolonged labor or first stage over 12 hours as defined in some studies. According to Kochran et al, who included 13 experiments with 1995 participants, the use of antispasmodic drugs shortened the first stage of labor by an average of 74.34 minutes. In 6 experiments that included 820 patients, the administration of antispasmodic drugs during labor increases the rate of cervical opening by an average of 0.61 cm per hour.

In addition to the muscle relaxation effect, studies have been published on the analgesic effect of PAPAVERINE for example in patients with urinary stones.

In the present study, the investigators want to test the effect of administering PAPAVERINE IV 80 mg within half an hour before the insertion of a catheter balloon for cervical ripening on the Bishop score after catheter removal between the two groups.