Analysis of 100 pregnancy outcomes in women treated systemically with tacrolimus.

The aim of this paper is to provide a summary of clinical findings regarding the safety of tacrolimus in pregnancy. From 1992 to 1998 data were collected on 100 pregnancies from 84 mothers who received tacrolimus systemically; 83 cases of solid organ transplantation, and 1 case of Behçet's disease. Maternal mean age at conception was 28 years and pregnancy outcome was live birth in 68%, spontaneous abortion in 12%, induced abortion in 12%, stillbirth/perinatal death in 3%, ongoing pregnancy in 2%, and lost to follow up in 3%. Fifty-nine percent of the neonates were delivered prematurely (< 37 weeks of gestation). Birth weight was appropriate for the gestational age in 90% of the cases. Malformations occurred in 4 neonates: case 1, meningocele and urogenital defects; case 2, alcoholic embryopathy; case 3, ear defect, cleft palate and hypospadia; case 4, multicystic dysplastic kidney. There was no consistent pattern of malformations and 2 mothers subsequently delivered a healthy neonate while on tacrolimus therapy. Nearly 70% of pregnancies following systemic tacrolimus administration resulted in a favourable outcome without any significant effect on intrauterine growth. The incidence of malformations was similar to that reported with other immunosuppressants in transplant recipients.

Review of the course and outcome of 100 pregnancies in 84 women treated with tacrolimus.

BACKGROUND: The increasing use of tacrolimus as a primary immunosuppressant is paralleled by a growing number of pregnancies occurring in mothers receiving tacrolimus systemically. METHODS: In this retrospective analysis during 1992-1998; data sources were case reports from clinical studies, spontaneous reports from health care professionals, routine surveys by transplant registries, and the published literature. RESULTS: One hundred pregnancies in 84 mothers were recorded. Mean maternal age was 28 years. All except one mother (autoimmune disease) were solid organ transplant recipients (66% liver and 27% kid- ci ney). Mean time from transplantation to conception was 26 months. The mean daily dose of tacrolimus (range 11.7-12.8 mg/day) and the mean tacrolimus whole blood level (range 8.5-11.5 ng/ml) remained fairly constant from preconception through the third trimester. The most frequent maternal complications were graft rejection followed by preeclampsia, renal impairment, and infection. All cases of rejection were successfully treated with corticosteroids and did not result in graft loss. Of 100 pregnancies, 71 progressed to delivery (68 live births, 2 neonatal deaths, and 1 stillbirth), 24 were terminated (12 spontaneous and 12 induced), 2 pregnancies were ongoing, and 3 were lost to follow-up. Mean gestation period was 35 weeks with 59% deliveries being premature (<37 weeks). The birth weight (mean 2573 g) was appropriate for gestational age in 90% of cases. Most common complications in the neonate were hypoxia, hyperkalemia, and renal dysfunction. These were transient in nature. Four neonates presented with malformations, without any consistent pattern of affected organs. CONCLUSION: Pregnancy in tacrolimus-treated transplant recipients resulted in a favourable outcome. Complications of the mother and neonate were similar to those previously described with other immunosuppressants.

Evaluation of the bronchodilator properties of Ro 31-6930, a novel potassium channel opener, in the guinea-pig.

1. Ro 31-6930 (0.001-0.3 microM), cromakalim (0.03-3.0 microM), salbutamol (0.001-0.3 microM) and theophylline (0.3-100 microM) evoked dose-related reductions in guinea-pig spontaneous tracheal tone with IC50 values of 0.044, 0.20, 0.021 and 21.0 microM respectively. All four agents also relaxed tone supported by betahistine, carbachol, 5-hydroxytryptamine (5-HT), leukotriene D4 (LTD4), U46619 and prostaglandin D2 (PGD2). The order of potency of tracheal relaxants was always salbutamol greater than Ro 31-6930 greater than cromakalim greater than theophylline. 2. All four agents evoked dose-related reductions in 5-HT- and histamine-induced bronchoconstriction in pithed vagotomised guinea-pigs. The dose of Ro 31-6930 producing 50% inhibition of a 5-HT bronchoconstriction was 11.6 micrograms kg-1 and the dose producing 50% inhibition of a histamine bronchoconstriction was 4.4 micrograms kg-1. Salbutamol was approximately 4-5 times more potent than Ro 31-6930 whilst cromakalim was approximately 10 times less potent than Ro 31-6930 as a bronchodilator. Theophylline was markedly less potent than any of the other agents. 3. Ro 31-6930, cromakalim, salbutamol and theophylline each protected conscious guinea-pigs from histamine-induced respiratory distress. Ro 31-6930 and salbutamol were each effective at oral doses of 1.0 and 3.0 mg kg-1 whilst cromakalim was effective at oral doses of 3.0 and 10.0 mg kg-1. Theophylline showed activity only at 300 mg kg-1 p.o. 4. Ro 31-6930 is a novel potassium channel opener which is a potent relaxant of guinea-pig tracheal smooth muscle in vitro and a bronchodilator in vivo.

Preclinical pharmacology of Ro 31-6930, a new potassium channel opener.

The present study compares the effects of Ro 31-6930, a novel potassium channel opener, with those of cromakalim and nitrendipine on blood pressure and other haemodynamic parameters. In conscious, spontaneously hypertensive rats (SHR) the oral dose of Ro 31-6930 for lowering blood pressure was 10 times lower than that of cromakalim and some 100 times lower than that of nitrendipine. In addition, the duration of antihypertensive activity of Ro 31-6930 was longer than that of cromakalim or nitrendipine. The tachycardia evoked by Ro 31-6930 and cromakalim was of shorter duration than the antihypertensive effect of either agent. In a repeat, once daily dosing experiment no tolerance was observed to the antihypertensive effect of Ro 31-6930 over a 22-day period. In conscious normotensive cats Ro 31-6930 was 10 times more potent than cromakalim and 1,000 times more potent than nitrendipine in reducing blood pressure. The duration of hypotensive activity was in excess of 5 h for each agent. In anaesthetised dogs all three agents reduced mean arterial pressure (MAP) and total peripheral resistance (TPR), while increasing cardiac output (CO) via a rise in stroke volume (SV). Both Ro 31-6930 and cromakalim significantly reduced femoral (FVR) and mesenteric vascular resistances (MVR), while only cromakalim reduced renal vascular resistance (RVR). Ro 31-6930 is a potent new antihypertensive agent that compares favourably with cromakalim and nitrendipine.

The effects of a new opioid analgesic, meptazinol, on the respiration of the conscious rat.

In the conscious rat arterial PCO2 was measured as an index of respiratory status. The opioid analgesic meptazinol (7.5 - 30 mg kg-1) evoked small but significant increases in arterial PCO2 which were attenuated by naloxone. Meptazinol significantly reduced the increase in arterial PCO2 evoked by morphine. The respiratory depression induced by meptazinol, but not that induced by morphine, was enhanced by pretreatment with atropine. The (+)-enantiomer, but not the (-)-enantiomer of meptazinol increased arterial PCO2. In contrast, only the (-)-enantiomer reduced the respiratory depressant effect of morphine. It is proposed that the degree of respiratory depression induced by meptazinol is limited by its opioid antagonist and cholinomimetic properties.