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Biomedical subjects

J M Merkus

Publications and source records attributed to J M Merkus.

At least 37 records · Page 2Linked to original sources
PubMed1996

Double-blind evaluation of ritodrine sustained release for oral maintenance of tocolysis after active preterm labour.

OBJECTIVE: To evaluate the effect of ritodrine sustained release capsules for maintaining uterine quiescence after successful treatment of active preterm labour. DESIGN: Multicentre placebo-controlled trial. SETTING: Five teaching hospitals in the Netherlands. PARTICIPANTS: Women (n = 95) at less than 35 weeks of gestation in whom active preterm labour had been stopped with intravenous ritodrine. INTERVENTIONS: Women received either two 40 mg ritodrine sustained release capsules (n = 50) or identical placebo capsules (n = 45) three times a day for seven days. RESULTS: The proportion of women who received another course of active treatment was significantly smaller with the sustained release than with placebo (1 of 50 versus 11 of 45: P = 0.003) as was the number delivering because of preterm labour during treatment (0 of 50 versus 4 of 45: P = 0.04). There were no other significant differences between the two groups. CONCLUSIONS: Maintenance treatment with ritodrine sustained release capsules after arrest of preterm labour reduces the risk of recurrences of preterm labour that necessitate treatment or precipitate delivery.

Administration, Oral↗
PubMed1993

A loading model for ritodrine administration in preterm labour.

OBJECTIVE: To develop a ritodrine infusion scheme for preterm labour that avoids plasma levels above those needed for tocolysis, requires only one rate adjustment, and is easy to apply in practice. DESIGN: Prospective study of tocolytic effect and plasma ritodrine concentrations during application of the infusion scheme. SETTING: High risk labour ward. SUBJECTS: Consecutive series of 31 women in labour at less than 36 weeks' gestation. INTERVENTION: Loading dose ritodrine infusion followed, as soon as tocolysis is reached, by a decrease in the infusion rate calculated on the basis of the interval between start of treatment and tocolysis. RESULTS: Overall, steady state ritodrine levels were nearly identical to those at the time of tocolysis and correlated well with levels anticipated on the basis of our calculation (n = 30; r = 0.91; P < 0.001). Adjustments during steady state were made in 12 women (40%), but in only two of them within 12 h after tocolysis had been reached. Delivery was postponed for more than 48 h in 29 women (93.5%) and beyond 37 weeks' gestation in 19 (61.3%). CONCLUSION: The loading model is easy to apply, avoids relative overdoses, requires few adjustments, is well tolerated, uses smaller quantities of ritodrine, and results in lower plasma ritodrine concentrations than the conventional infusion scheme.

Dose-Response Relationship, Drug↗
PubMed1992

Intranasal administration of estradiol in combination with progesterone to oophorectomized women: a pilot study.

A pilot study was done to investigate the pharmacokinetics and acceptability of an intranasal 17 beta-estradiol/progesterone formulation. This formulation contained dimethyl-beta-cyclodextrin as a solubilizer and absorption enhancer of the steroid hormones. The study was performed in four oophorectomized and hysterectomized patients. After nasal delivery of 0.34 mg estradiol and 0.85 mg progesterone, concentration-time curves of progesterone, estradiol and its metabolite estrone were established. Rapid absorption of progesterone and estradiol was demonstrated. Progesterone peak-levels (3.9-6.7 nmol/l) exceeded the levels which are found in the follicular phase of the menstrual cycle, but did not reach the levels of the luteal phase. Comparison with an earlier reported study in which only estradiol was administered shows that the addition of progesterone does not alter the absorption and pharmacokinetics of estradiol. The nasal formulation was well accepted by the four patients and no adverse effects were noted.

Administration, Intranasal↗
PubMed1991

Infertility treatment: implications for perinatology.

From 1975 to 1989 multiple birth rate in The Netherlands increased with almost 40%. Only a quarter of the increase can be related to births after in vitro fertilization. Evidence is presented that ovulation induction as an independent therapy or in combination with other forms of assisted reproduction is highly responsible for the rising number of multiplets. As a consequence, a heavy burden is placed on the units for specialized neonatological care as well as on the obstetrical wards in the tertiary centres for neonatology. Doctors should become aware of the facts and should inform the public properly about the risks of multiple pregnancy. An international approach is needed to get insight in the problems and to develop effective policies for the future.

Birth Weight↗
PubMed1991

Intranasal estradiol administration to oophorectomized women.

An open, dose-finding study into the effects of a new intranasal 17 beta-estradiol formulation using dimethyl-beta-cyclodextrin as a solubilizer was conducted in nine hysterectomized and oophorectomized patients with symptoms of estrogen deficiency. After nasal delivery of 0.34 mg estradiol in three patients, concentration-time curves of estradiol in serum and its metabolite estrone in plasma were established. High initial estradiol serum levels were found in the order of 5 nmol/l. Estrone/estradiol ratios were below unity, whereas, in contrast, estrone/estradiol ratios after oral administration of estradiol are known to exceed unity. Biological activity, as reflected by suppression of FSH and LH, was manifest. In nine patients symptoms of estrogen deficiency were assessed by a questionnaire. After 3 and 6 months of treatment, a clinically and statistically significant decrease (P less than 0.01) of the total score according to this questionnaire was found compared to the beginning of the study. Thus nasal delivery of estradiol using this cyclodextrin formulation has potential for further clinical evaluation.

Administration, Intranasal↗
PubMed1991

A fetal cystic neck mass associated with maternal tuberous sclerosis. Case report and literature review.

Tuberous sclerosis is a single gene autosomal-dominant disorder, characterized by multiple hamartoma formation. It shows a wide variability of expression. Prenatal diagnosis by means of a DNA or biochemical marker is not yet possible. Ultrasound offers the only way to detect possible antenatal hamartoma formation, which is most commonly found in the central nervous system, the renal system, and the heart. We report a case of fetal involvement that appears unique because of the unusual location of a tumour in the neck of the fetus.

Adult↗
PubMed1990

Chronic recurrent vaginal candidosis: easy to treat, difficult to cure. Results of intermittent treatment with a new oral antifungant.

Research into the pathogenesis and treatment of chronic recurrent candidosis vaginalis did not come up with a clear answer of curing this phenomenon. In this investigation, data are presented of a therapy with a new antifungal agent, itraconazole. After a therapeutic treatment course, 17 patients received a prophylaxis for CRCV over 6 months. The treatment schedule for prophylaxis consisted of 4 capsules of 50 mg itraconazole on day 5 and 6 of the menstrual cycle. Eleven remained symptom-free in this period. Although there is no explanation for recurrence in most cases of CRCV, intermittent treatment schedules can be used to treat but not to cure these patients. Data of this investigation and data mentioned in the literature prove the necessity to discriminate between a sympatomtic and a mycological cure.

Administration, Oral↗
PubMed1990

Treatment of vaginal candidiasis: orally or vaginally?

Vaginal candidiasis continues to be the most common cause of vaginal discharge. A large variety of topical drugs and a selection of orally active antifungals are currently available. The choice between the use of oral drugs or intravaginal agents will depend on the therapeutic results obtained with the different agents, side effects, pregnancy status, and patient preference. The results obtained in the Maria Hospital, Tilburg, The Netherlands, and a review of foreign data suggest the following: (1) For acute infection oral and topical agents produce equivalent results. (2) For chronic infections oral medication is preferred. (3) Oral therapy should not be given to pregnant patients or to patients not using reliable contraceptive measures. (4) Half the patients prefer oral medication; only 5% prefer intravaginal therapy, and the others had no clear preference.

Administration, Intravaginal↗
PubMed1990

Chronic vulvovaginal candidosis: the role of oral treatment.

Fluor vaginalis may have a diversity of causes, among which are fungal infections by Candida spp. It has been estimated that up to 75% of women will have at least one episode of vaginal candidosis during their reproductive years. Most of these women have had only one occasional episode of discomfort. However, a small group presents with a chronic recurrence of vaginal candidosis accompanied by symptomatic infections many times a year. Until now, investigations into the pathogenesis and treatment of these recurrent episodes gave no clear answer to the question as to why this occurs in these patients. The opportunity to treat vaginal candidosis with a systemic antifungal drug can have advantages over a topical drug, if extravaginal Candida spp. that may contribute to recurrence can be eliminated at the same time. In this trial, 18 patients with chronic recurrent vaginal candidosis (greater than 4 attacks of candidosis vaginalis per year) were treated with itraconazole 200 mg/day monthly for two days--Days 5 and 6 after menstruation. After the first therapeutic treatment, 17 patients were culture-negative and symptom-free. Results show that prophylaxis for six months with itraconazole was beneficial, as far as complaints were concerned, in 11 patients (64.7%).

Administration, Oral↗
PubMed1987

A loading-dose infusion scheme for intravenous tocolysis with ritodrine: a pilot study.

A loading-dose infusion scheme for intravenous ritodrine therapy was tested in twelve patients with preterm labour. We started with a rather high (386 micrograms/min) infusion rate, but the moment tocolysis was reached this infusion rate was reduced to a level needed to maintain the plasma concentration then found. Plasma samples of ritodrine were taken the moment tocolysis was reached and in the steady state, and compared with each other and with expected and calculated plasma concentrations. In the dynamic loading phase we found a half-life for ritodrine of 1 h. This half-life of 1 h can be explained by cumulation of ritodrine in the central compartment and is therefore called cumulation t1/2. In developing an infusion scheme with a loading dose for ritodrine, this cumulation t1/2 of 1 h should be taken into account.

Adult↗
PubMed1987

Effect of Bellergal Retard on climacteric complaints: a double-blind, placebo-controlled study.

The effect of Bellergal Retard (BR) on climacteric complaints was evaluated versus a placebo in an 8-wk double-blind study, followed by a 4-wk open study in which only BR was used as medication. There was a marked decrease in complaints in both the BR and the placebo groups. Statistically significant differences were observed between the groups after 2 and 4 wk of treatment, indicating superior results with BR. After 8 wk of study however, these differences were no longer apparent. It was concluded that studies on medication for climacteric complaints should not only be placebo-controlled, but also be of at least 8 to 12 wk duration for proper evaluation.

Belladonna Alkaloids↗
PubMed1986

Co-treatment of the male partner in vaginal candidosis: a double-blind randomized control study.

In a double-blind study, 117 non-pregnant women with vaginal candidosis were treated for 3 days with 200 mg-tablets of ketoconazole taken once, twice or three times daily. The incidence of predisposing factors or of a recurrence history did not differ between treatment groups. Their male partners were randomly assigned to receive ketoconazole, 200 mg twice daily or placebo for 3 consecutive days. Cure and recurrence rates were not different in the three treatment groups, with or without simultaneous treatment of the male partner. Treatment of the sexual partner in the three dose-regimen-groups proved not to have influenced the therapeutic effect.

Adolescent↗
PubMed1985

Cerebral haemorrhage in a pregnant woman with a multiple endocrine neoplasia syndrome (type 2A or Sipple's syndrome).

We present the case history of a 30-yr-old woman who suffered a cerebral haemorrhage toward the end of pregnancy (at 35 wk). The pregnancy was terminated by Caesarean section because aggravation of cerebral bleeding was feared. Extensive studies revealed that the patient was suffering from a multiple endocrine neoplasia syndrome (type 2A or Sipple's syndrome) with bilateral pheochromocytomas and a medullary thyroid carcinoma. She made an uneventful recovery. The relevant literature is discussed.

Adrenal Gland Neoplasms↗