Dixyrazine premedication for cataract surgery. A comparison with diazepam

Peroral dixyrazine (15–30 mg, n = 50) and diazepam (4–10 mg, n = 50) were used as premedicants for geriatric patients having cataract surgery under regional block. Compared to the diazepam patients, a larger number of the dixyrazine medicated patients appeared anxious, and there was a statistically significant difference between the groups, when summing up changes in anxiety throughout the study period. The dixyrazine patients needed more frequent supplementation with intravenous sedative drugs, compared with their diazepam counterparts. Peroral dixyrazine is an applicable choice for calm patients, when only slight sedation, or avoidance of somnolence are required.     

Dixyrazine,a phenothiazine derivate,can prevent brain oedema induced by intracarotid injection of protamine sulphate

Summary The present study was performed to determine whether an opening of the blood-brain barrier (BBB) induced by intracarotid infusion of protamine sulphate necessarily leads to brain oedema and, if so, whether dixyrazine, a phenothiazine, can prevent the oedema. Evans blue albumin was used to detect BBB opening. Endogenous serum albumin was determined in CSF sampled before and after protamine infusion.The brain specific gravity, a sensitive indicator of brain oedema, was determined one hour after intracarotid infusion of 5 or 10 mg protamine sulphate in 100 or 200 l solvent in rats. Both doses opened the BBB and the CSF albumin was significantly increased (p<0.05 for 5 mg and p<0.01 for 10 mg protamine sulphate). However, only 10 mg protamine significantly reduced the specific gravity in the cerebral cortex and basal ganglia in the right (injected) hemisphere. Pretreatment with dixyrazine 10 mg/kg completely prevented the brain oedema and significantly reduced the albumin increase in CSF. We conclude that a) a moderate opening of BBB induced by 5 mg protamine sulphate does not lead to brain oedema and b) dixyrazine can prevent the brain oedema induced by 10 mg protamine sulphate.     

Intravenous sedation and regional analgesia

A double-blind study of 229 patients with the use of intravenous diazepam as compared with a placebo to produce sedation during local analgesia showed that significantly improved sedation occurred when diazepam was used. The diazepam was dissolved in cremophor and this reduced the pain of intravenous injection of the diazepam. One patient who received Cremophor only, showed a moderately severe allergic reaction. It is suggested that a small test dose should always be given before giving any drug which is dissolved in Cremophor.     

Gas chromatographic — Mass spectrometric determination of dixyrazine in human blood

Summary A gas chromatographic — mass spectrometric method for the determination of dixyrazine in plasma has been developed. The method was found to offer high specificity, sensitivity, accuracy and precision and should be adequate for analysis of dixyrazine kinetics in man. There appeared to be great inter-individual variation in the disposition of the drug.Deceased     

A double blind study in out-patients with primary non-agitated depression treated with imipramine in combination with placebo, diazepam or dixyrazine

Sixty-three out-patients suffering from primary non-agitated depression were included in a double-blind, between-patient randomized study. All patients were treated with imipramine (100-200 mg-day) combined with either placebo, diazepam (10 mg/day) or dixyrazine (50 mg/day) for 8 weeks. The clinical efficacy assessed with a subscale of CPRS was significantly (p1 less than or equal to 0.05) better for the imipramine-dixyrazine combination than for the imipramine-diazepam or imipramine-placebo combination. Serum concentration of imipramine was significantly higher (p1 less than or equal to 0.05) in the group treated with dixyrazine than in the other two groups. Further, serum concentration of imipramine in the diazepam group was significantly lower (p1 less than or equal to 0.05) than in the placebo group. At the end of the study, 67% in both the placebo and the diazepam group and 86% in the dixyrazine group were practically symptom-free.     

Increased antipanic efficacy in combined treatment with clomipramine and dixyrazine

A double-blind 12 week trial was undertaken to compare the effects of clomipramine + dixyrazine with clomipramine + placebo in the treatment of panic disorder with or without agoraphobia. Of 45 patients included (21 dixyrazine, 24 placebo), 16 dropped out (6 dixyrazine, 10 placebo). The number of panic attacks and the scores on the panic disorder subscale of the Hamilton Anxiety Rating Scale were significantly reduced in response to both treatment regimens, but the reduction was significantly greater in the dixyrazine group. The patients’ daily functioning was significantly more improved with the dixyrazine combination. The serum concentration of desmethylclomipramine monotherapy was significantly higher and the side effects significantly lower in the combined treatment with dixyrazine than with clomipramine monotherapy. Clomipramine combined with dixyrazine seems superior to clomipramine in the treatment of panic disorder.     

Comparison of the serum levels in primary non-agitated depressed out-patients treated with imipramine in combination with placebo, diazepam or dixyrazine

Sixty-three non-agitated depressed out-patients were selected according to the Feighner-Robins-Guze criteria for primary depressions for a double-blind, between-patient randomized study for an 8 week duration. All the patients were treated with imipramine following a fixed dose schedule for the first 2 weeks and thereafter according to clinical response (100-200 mg/day). This treatment was combined with either placebo, diazepam (10 mg/day) or dixyrazine (50 mg/day). The serum concentration of imipramine both at 2 weeks and later was significantly higher (P less than 0.05) in the group treated with dixyrazine than in the other two groups. In the group treated with diazepam, the serum levels of imipramine and desipramine were significantly lower than in the placebo group. The serum concentrations of diazepam, desmethyldiazepam and dixyrazine were almost unchanged during the study. No significant correlation was found between the dosage and the serum concentration of imipramine or desipramine. The change in mean CPRS-score correlated neither with the imipramine nor with the desipramine serum levels, it did correlate but negatively with the degree of side effects. The degree of side effects correlated positively with the serum concentration of desipramine.     

Postoperative emesis after pediatric strabismus surgery: the effect of dixyrazine compared to droperidol

Sixty-one children, ASA physical status I, aged 2-14 years, admitted for strabismus surgery were studied. All were premedicated with diazepam and atropin rectally. Anesthesia was induced with thiopental or with halothane on a facemask, and succinylcholine was given to facilitate tracheal intubation. Anesthesia was maintained with halothane and nitrous oxide. Each child was randomly assigned to receive either no antiemetic prophylaxis (control), droperidol 0.075 mg/kg, or dixyrazine 0.25 mg/kg. The drugs were injected intravenously at the end of surgery. The incidence of vomiting during the following 24 h was 65% in the control group, 48% in the droperidol group, and 25% in the dixyrazine group (P less than 0.05 as compared to the control group). Four hours after the operation, six children in the droperidol group and none in the dixyrazine group (P less than 0.05) were difficult to arouse. It is concluded that dixyrazine reduces the incidence of postoperative vomiting without causing heavy sedation.