Increasing the human chorionic gonadotrophin cut-off to ≤1000 IU/l for starting actinomycin D in post-molar gestational trophoblastic neoplasia developing resistance to methotrexate spares more women multi-agent chemotherapy

Background

A human chorionic gonadotropin (hCG) cut-off of ≤300 IU/l for starting actinomycin D (ActD) in post-molar gestational trophoblastic neoplasia (GTN) patients developing methotrexate resistance (MTX-R) reduced the number of women needing toxic multi-agent chemotherapy (etoposide, MTX and ActD alternating weekly with cyclophosphamide and vincristine; EMA/CO) without affecting survival. Here we assess whether an increased hCG cut-off of ≤1000 IU/l spares more women EMA/CO.

Patients and methods

All post-molar GTN patients treated with first-line methotrexate and folinic acid (MTX/FA) were identified in a national cohort between 2009 and 2016. Data collected included age, FIGO score, the hCG levels at MTX-R, and treatment outcomes.

Results

In total, 609 GTN patients commenced treatment with MTX/FA achieving a complete response in 57% (348/609). Resistance developed in 25.1% (153/609) at an hCG ≤ 1000 IU/l and switching to ActD achieved remission in 92.8% without any major toxicity with the remaining 7.2% remitting on EMA/CO. Comparative analysis of patients switching at an hCG <100 versus 100-300 versus 300-1000 IU/l revealed a significant fall in the cure rate with second-line ActD from 97% (93/96) to 87% (34/39) to 78% (14/18), respectively, P = 0.009. However, by increasing the hCG cut-off from ≤300 to ≤1000 IU/l, 14 patients were spared EMA/CO chemotherapy. Moreover, in the present series, all post-molar GTN remain in remission.

Conclusion

This study demonstrates that increasing the hCG cut-off from ≤300 to ≤1000 IU/l for choosing patients for ActD following MTX-R spares more women with GTN from the greater toxicity of EMA/CO without compromising 100% survival outcomes.

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An hCG cut-off of ≤1000 IU/l for ActD over EMA/CO treatment in MTX-R GTN spares women toxicity without affecting survival.

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On developing MTX-R, as the hCG cut-off for selecting ActD versus EMA/CO rises, the complete response rate for ActD falls.

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Half of FIGO-7 patients were cured on single-agent treatment (MTX/FA or sequential ActD), warranting further investigation.

Pharmacokinetics of intramuscular artemether in patients with severe falciparum malaria with or without acute renal failure

AIMS

The pharmacokinetics of intramuscular artemether and its major plasma metabolite-dihydroartemisinin, were investigated in patients with severe manifestations of falciparum malaria.

METHODS

Six severe falciparum malaria patients with acute renal failure (ARF) and 11 without ARF were recruited into the study. They were treated with intramuscular artemether at a loading dose of 160 mg, followed by daily doses of 80 mg for another 6 days (total dose 640 mg).

RESULTS

Patients with and without ARF showed a good initial response to treatment; the parasite and fever clearance times were 66(30-164) and 76(36-140) h [median(range)], respectively. None had reappearance of parasitaemia in their peripheral blood smear within 7 days of initiation of treatment. In comatose patients, the time to recovery of consciousness was 51.6(22-144) h. Artemether was detected in plasma as early as 1 h after a 160 mg dose, and declined to undetectable levels within 24 h in most cases. Patients with ARF had significantly higher Cmax [2.38(1.89-3.95) vs 1.56(1.05-3.38) ng ml(-1) mg(-1) dose], AUC [35.4(22-52.9) vs 25.2(13.4-52.9) ng ml(-1) h mg(-1) dose], and lower Vz/F [5.45(3.2-6.9) vs 8.6(4.2-12.3) l kg(-1)] and CL/F [7.4(5.4-13.8) vs 19.1(8.5-25.1) ml min(-1) kg(-1)] when compared with those without ARF. In addition, t1/2,z was significantly longer in ARF patients [7.0(5.5-10.0) vs 5.7(4.2-6.6) h]. The pharmacokinetics of dihydroartemisinin in the two groups of patients were comparable.

CONCLUSIONS

ARF significantly modified the pharmacokinetics of intramuscular artemether. The changes could be attributed to either improved absorption/bioavailability, a reduction of systemic clearance, or a change in plasma protein binding of the drug.

Plasma quinine concentrations in falciparum malaria with acute renal failure

Plasma quinine (Qn) monitoring was performed in 32 patients with severe falciparum malaria (10 with acute renal failure (ARF) and 22 with other severe manifestations) who were treated with the standard regimen of 10 mg/kg body weight Qn dihydrochloride, with a loading dose of 20 mg/kg body weight. Median plasma Qn concentrations prior to the first dose on each day were approximately 10-30% higher in ARF patients than in non-ARF patients during acute infection. Seven patients underwent haemodialysis; 2 died after 2 cycles. There were no significant changes in plasma Qn concentrations in patients with ARF during haemodialysis. No Qn was detectable in haemodialysate fluids. This suggests that dosage adjustment of Qn during haemodialysis is unnecessary. Cardiotoxity of Qn must be of concern in malaria patients with ARF after 3 days of Qn therapy, and ECG monitoring during Qn infusion is recommended in all severe malaria patients with persistent ARF. If there is any arrhythmia, the infusion should be discontinued. However, in some hospitals where ECG facilities are not available, reduction in Qn dosage in persistent ARF patients should be considered after the third day of therapy. The appropriate dosage reduction should be further studied. Monitoring of total plasma Qn concentrations (which has been used routinely) is of no value for predicting the cardiotoxicity in ARF patients; monitoring of free Qn would be more appropriate. However, ECG seems to be the practical procedure to monitor cardiotoxicity of Qn. It may be possible to use the QTc interval to estimate the Qn concentration in severe malaria patients without ARF, but not in patients with persistent ARF.

Comparison of artemether and quinine in the treatment of severe falciparum malaria in south-east Thailand

One hundred and two Thai patients with severe falciparum malaria (92 males and 10 females) were allocated at random to receive either the standard regimen of quinine infusion (52 cases) or intramuscular artemether (50 cases). The patients in both groups had comparable admission clinical and laboratory data. Artemether gave a better survival rate (87.2% vs. 63.3%) and parasite clearance time (54 vs. 78 h) than quinine. Fever clearance times (79 h vs. 84 h) and time to recovery of consciousness (48 h in both groups) were comparable. Previous treatment with quinine or mefloquine had no influence on treatment outcome. The most common adverse effect in patients treated with quinine was tinnitus. Two patients had severe hearing impairment which resolved within 1 week after the end of treatment. Mild, transient pain was noted at the injection site of artemether but no abscess formed. QTc wave prolongation was seen in most patients receiving quinine; however, no arrhythmia was observed despite the high concentration of quinine in some patients who had received quinine before admission. Complications developed in 7 survivors in each treatment group. No patient in the artemether group had neurological sequelae after recovery of consciousness, but 2 in the quinine group had left facial palsy and one had a myasthenia gravis-like syndrome. No patient died with complications in he artemether group, but 7 died with pulmonary complications in the quinine group.

Clinical response and susceptibility in vitro of Plasmodium vivax to the standard regimen of chloroquine in Thailand

The clinical effectiveness of the standard regimen of chloroquine (CQ) (a total dose of 1500 mg, given over 48 h at 0, 6, 24 and 48 h) for the treatment of Plasmodium vivax malaria in Thailand was investigated in 57 patients in an endemic area of Thailand (Chantaburi Province, eastern Thailand). For radical treatment, an additional course of a tissue schizontocidal agent, primaquine, was given following the complete course of CQ. With this regimen, satisfactory whole blood concentration-time profiles of CQ and its major metabolite desethylchloroquine (DECQ) were achieved. Mean whole blood levels of CQ and DECQ always much exceeded the reported therapeutic level of CQ (90 ng/mL) during the first 7 d of treatment. All patients responded well to the treatment; in most cases, complete and rapid clearance of parasitaemia was observed within the first 48 h. No reappearance of the parasitaemia was detected in peripheral blood films of any patient within 14 d of the evaluation period. In 6 patients, however, reappearance of P. vivax parasitaemia was observed after 30 d; 2 of them had not completed the course of primaquine. There was no difference in whole blood concentrations of CQ and DECQ, admission parasitaemia, susceptibility of the isolates to chloroquine in vitro, and parasite clearance time between patients with or without reappearance of parasitaemia. A prominent trend of deteriorating sensitivity of the parasite to the drug was, however, suggested.

Electroencephalography in cerebral malaria

Electroencephalography (EEG) was performed in 13 male patients with cerebral malaria during the first 24 hours of admission, using a 10-channel, 10-20 system EEG machine (6 montages, 20 minute duration). The EEG patterns were of theta and delta waves from both sides of cerebral hemisphere suggesting diffused cortical dysfunction. No epileptic pattern was found in patients who had seizures prior to, or after admission. The initial EEG performed on the day of admission did not show any specific pattern attributable to any pathological condition. It was also unable to predict the prognosis of the 2 dead patients. However, one cerebral malaria patient with left hemiplegia was subsequently found to have right basal ganglia hemorrhage in CAT scan, high amplitude delta waves and theta waves in the tracings of the right hemisphere. The study suggests that a single EEG data on admission can hardly give enough information for prediction of the clinical course and outcome of cerebral malaria. Serial EEGs probably provide more useful information regarding the prognostic signs in this group of patients. Nevertheless, EEG could be useful to rule out some cerebral pathology such as space occupying lesions, epilepsy or any other causes of unconsciousness that could produce similar cerebral symptoms in malaria patients.

Preliminary report: a comparative clinical trial of artemether and quinine in severe falciparum malaria

Twenty-six patients with severe falciparum malaria were randomized to be treated with quinine or artemether. Twelve patients received quinine at the standard dose and fourteen patients received artemether intramuscularly at a total dose of 640 mg over 7 days. The patients were kept in the hospital for at least 7 days. Peripheral smear was performed 6-hourly until there was no parasitemia, then daily until discharged. Adverse effects were monitored through physical examination, laboratory findings and questionnaires. Laboratory examination was performed on admission, day 2, day 4 weekly until discharged. The patients in both groups were comparable in age, body weight, admission parasitemia, hemoglobin and white blood cell count. The survival rates were 93% and 58% in artemether and quinine groups, respectively (p = 0.052 at 95% confidence, using Fisher's exact test). The parasite and fever clearance times, and the time taken to gain consciousness in cerebral malaria patients were not significantly different between the two groups. Adverse effects in the quinine group consisted of dizziness and vertigo which were found in 4 patients. No adverse effects were noticed in the artemether group. This preliminary report suggests that artemether is a good alternative drug for severe falciparum malaria and seems to be better than quinine regarding survival rate and side effects. Confirmation of these findings in a larger study size is needed.