Prevalence and features of delirium in older patients admitted to rehabilitation facilities: a multicenter study

BACKGROUND

Delirium is thought to be common across various settings of care; however, still little research has been conducted in rehabilitation.

AIM

We investigated the prevalence of delirium, its features and motor subtypes in older patients admitted to rehabilitation facilities during the three editions of the "Delirium Day project".

METHODS

We conducted a cross-sectional study in which 1237 older patients (age ≥ 65 years old) admitted to 50 Italian rehabilitation wards during the three editions of the "Delirium Day project" (2015 to 2017) were included. Delirium was evaluated through the 4AT and its motor subtype with the Delirium Motor Subtype Scale.

RESULTS

Delirium was detected in 226 patients (18%), and the most recurrent motor subtype was mixed (37%), followed by hypoactive (26%), hyperactive (21%) and non-motor one (16%). In a multivariate Poisson regression model with robust variance, factors associated with delirium were: disability in basic (PR 1.48, 95%CI: 1.17-1.9, p value 0.001) and instrumental activities of daily living (PR 1.58, 95%CI: 1.08-2.32, p value 0.018), dementia (PR 2.10, 95%CI: 1.62-2.73, p value < 0.0001), typical antipsychotics (PR 1.47, 95%CI: 1.10-1.95, p value 0.008), antidepressants other than selective serotonin reuptake inhibitors (PR 1.3, 95%CI: 1.02-1.66, p value 0.035), and physical restraints (PR 2.37, 95%CI: 1.68-3.36, p value < 0.0001).

CONCLUSION

This multicenter study reports that 2 out 10 patients admitted to rehabilitations had delirium on the index day. Mixed delirium was the most prevalent subtype. Delirium was associated with unmodifiable (dementia, disability) and modifiable (physical restraints, medications) factors. Identification of these factors should prompt specific interventions aimed to prevent or mitigate delirium.

The association between low skeletal muscle mass and delirium: results from the nationwide multi-centre Italian Delirium Day 2017

Introduction

Delirium and sarcopenia are common, although underdiagnosed, geriatric syndromes. Several pathological mechanisms can link delirium and low skeletal muscle mass, but few studies have investigated their association. We aimed to investigate (1) the association between delirium and low skeletal muscle mass and (2) the possible role of calf circumference mass in finding cases with delirium.

Methods

The analyses were conducted employing the cross-sectional “Delirium Day” initiative, on patient 65 years and older admitted to acute hospital medical wards, emergency departments, rehabilitation wards, nursing homes and hospices in Italy in 2017. Delirium was diagnosed as a 4 + score at the 4-AT scale. Low skeletal muscle mass was operationally defined as calf circumference ≤ 34 cm in males and ≤ 33 cm in females. Logistic regression models were used to investigate the association between low skeletal muscle mass and delirium. The discriminative ability of calf circumference was evaluated using non-parametric ROC analyses.

Results

A sample of 1675 patients was analyzed. In total, 73.6% of participants had low skeletal muscle mass and 24.1% exhibited delirium. Low skeletal muscle mass and delirium showed an independent association (OR: 1.50; 95% CI 1.09–2.08). In the subsample of patients without a diagnosis of dementia, the inclusion of calf circumference in a model based on age and sex significantly improved its discriminative accuracy [area under the curve (AUC) 0.69 vs 0.57, p < 0.001].

Discussion and conclusion

Low muscle mass is independently associated with delirium. In patients without a previous diagnosis of dementia, calf circumference may help to better identify those who develop delirium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01950-8.

Weekly Doxorubicin Chemotherapy for Breast Cancer in Pregnancy. A Case Report

The simultaneous occurrence of breast cancer and pregnancy is rare. Little data are available about cytostatic treatment in patients with breast cancer during pregnancy. We report on a 31-year-old woman with a 28-week pregnancy and a T3 N+ Mx breast cancer treated with weekly doxorubicin chemotherapy. This was a well tolerated treatment without toxicity or complications for the mother. A partial response of the tumor was observed after 4 treatment courses. A normal baby was delivered. Doxorubicin and its metabolites were not detected in amniotic fluid collected through amniocentesis. Macroscopic and pathologic examinations of the placenta were normal. Although larger experiences are needed, weekly doxorubicin seems to yield satisfactory results without additional risks of fetal distress or malformations when given in women during the second and third trimester of pregnancy.

VO2 kinetics in supra-anaerobic threshold constant tests allow the visualization and quantification of the O2 saving after cytochrome c oxidase inhibition by aerobic training or nitrate administration

We tested whether the known cytochrome c oxidase (COX) inhibition by nitric oxide (NO) could be quantified by VO(2) kinetics during constant load supra-Anaerobic Threshold (AT) exercises in healthy trained or untrained subjects following aerobic training or nitrate administration. In cycle ergometer constant load exercises supra-AT, identified in previous incremental tests, VO(2) kinetics describe a double exponential curve, one rapid and one appreciably slower, allowing the area between them to be calculate in O(2) l. After training, with increased NO availability, this area decreases in inverse ratio to treatment efficacy. In fact, in 11 healthy subjects after aerobic training for 6-7 weeks, area was decreased on average by 51 %. In 11 untrained subjects, following the assumption of an NO donor, 20 mg isosorbide 5 mononitrate, area was decreased on average by 53 %. In conclusion, supra-AT VO(2) kinetics in constant load exercises permit the quantification of the inhibitory effect NO-dependent on COX after either physical training or nitrate assumption.

Predictors of the short-term effect of isoleucine-proline-proline/valine-proline-proline lactotripeptides from casein on office and ambulatory blood pressure in subjects with pharmacologically untreated high-normal blood pressure or first-degree hypertension

Our aim was to evaluate the predictors of Isoleucine-Proline-Proline/Valine-Proline-Proline (IPP-VPP) lactotripeptides (LTPs) antihypertensive effect in the context of a short-term large double-blind randomized clinical trial involving 164 pharmacologically untreated subjects in primary prevention for cardiovascular disease. When compared with the baseline, office systolic blood pressure (SBP) (-3.42 mm Hg, P < .001) and diastolic blood pressure (DBP) (-2.35 mm Hg, P < .001) significantly decreased, in the LTP-treated patients only. No significant change in predictors during the study of ambulatory blood pressure measurement (ABPM) parameters was observed. A short-term supplementation with LTPs significantly improves the office SBP and DBP, especially in male subjects. The main predictor of LTP antihypertensive effect was the baseline BP.

Effectiveness of a continuous quality improvement program on colonoscopy practice

BACKGROUND AND STUDY AIM

Continuous quality improvement (CQI) is recommended by professional societies as part of every colonoscopy program, but little is known with regard to its effectiveness for colonoscopy outcomes. We prospectively assessed whether the implementation of a CQI program in routine clinical practice influences the quality performance of colonoscopy.

METHODS

In an open-access endoscopy unit at a secondary care center in Northern Italy, 6-monthly audit cycles were carried out over a 4-year period, to identify reasons for poor colonoscopy outcomes and institute appropriate changes to improve performance. The colonoscopy completion rate and the polyp detection rate as detected by endoscopists were considered to be key measures for improvement.

RESULTS

The initial crude colonoscopy completion rate was 84.6%, with a range for individual endoscopists 80.4%-94%. Four endoscopists had a completion rate lower than 90%. The overall polyp detection rate was 34%, with a wide variation among endoscopists (range 14%-42%). Poor patient tolerance and differences in colonoscopist expertise were the main determinants of lack of completion and variation in polyp detection rate. Changes to sedation practice, greater access to endoscopy sessions for the endoscopists with the lowest performance rates, and other organizational arrangements, were implemented to improve quality performance. The crude completion rates improved consistently, up to 93.1%, over the study period. This trend was confirmed even when adjusted completion rates were calculated. All endoscopists reached a crude completion rate of 90% or more and a polyp detection rate of over 20%. The introduction of CQI did not significantly change the overall incidence of procedure-related complications.

CONCLUSIONS

The effectiveness of colonoscopy can be improved by implementing a CQI program in routine colonoscopy practice.

Analysis of deoxycytidine accumulation in gemcitabine treated patients

Deoxycytidine (CdR) analogs are increasingly popular as chemotherapeutic agents and their effectiveness can be linked to the direct competition with active forms of endogenous CdR. A tandem mass spectrometric assay was developed to determine the plasma concentrations of CdR. Plasma extracts were prepared by protein precipitation and an ethyl acetate/water back extraction, and then separated chromatographically. Detection parameters were optimized for multi-reaction monitoring (MRM) tandem mass spectrometry and assay efficiency was improved using 15N3 CdR as an isotopic internal standard. Preliminary results from a gemcitabine trial are shown which indicate that CdR concentrations increase systemically during infusion, from about 5 nM to 78 nM after hepatic artery infusion and to 102 nM after systemic infusion for 24 hours. The developed assay demonstrated good sensitivity and selectivity for CdR.

The determination of gemcitabine and 2'-deoxycytidine in human plasma and tissue by APCI tandem mass spectrometry

A fast, sensitive and accurate method for the determination of gemcitabine (difluorodeoxycytidine; dFdC) and deoxycytidine (CdR) in human plasma/tissue was developed using LC-MS/MS techniques. Effectiveness of the method is illustrated with the analysis of plasma from a phase I trial of dFdC administered as a 24h infusion. The method was developed using (15)N(3) CdR as an internal standard across the concentration range of 1-500ng/ml, using a cold alcohol-protein precipitation followed by desorption with freeze drying. Sample clean-up for LC-MS/MS analysis was performed by an innovative liquid/liquid back extraction with ethyl acetate and water. Chromatography was performed using a Chrompak-spherisorb-phenyl-column (3.1mmx200mm, 5microm) with a 50mM formic acid: acetonitrile (9:1) mobile phase eluted at 1ml/min. Extracted samples were observed to be stable for a minimum of 48h after extraction when kept at 4 degrees C. Detection was performed using an atmospheric pressure chemical ionization (APCI) source and mass spectrometric positive multi-reaction-monitoring-mode (+MRM) for dFdC (264 m/z; 112 m/z), CdR (228 m/z; 112 m/z), and (15)N(3) CdR (231 m/z; 115 m/z) at an ion voltage of +3500V. The accuracy, precision and limit-of-quantitation (LOQ) were as follows: dFdC: 99.8%, +/-7.9%, 19nM; CdR: 100.0%, +/-5.3%, 22nM, linear range LOQ to 2microM. During 24h infusion dFdC levels were detected with no interference from either CdR or difluorodeoxyuridine (dFdU). CdR co-eluted with dFdC but selectivity demonstrated no "crosstalk" between the compounds. In conclusion the analytical assay was very sensitive, reliable and robust for the determination of plasma and tissue concentrations of dFdC and CdR.

A comparative study on capecitabine (Cape) pharmacokinetics (PK) in elderly or younger patients with metastatic breast (MBC) or colo-rectal cancer (CRC)

12003

Background: Cape is an efficient oral prodrug of 5FU in MBC and CRC. Unexpected severe toxicity in older patients (pts) was reported after standard dose of 2500mg/sm/day. About 70% of drug and metabolites are excreted with the urine and a 25% reduction of the dose is recommended if the pt has a creatinine clearance (CrCl) <50ml/min. However no prospective study has been done on Cape PK in the elderly pts. Methods: Between Oct 2004 and Nov 2005, 21 pts with MBC or CRC and age ≥70yrs or ≤60yrs who received Cape (1000 mg/sm bid for 14 days every 21 days) entered the study after giving signed informed consent. CrCl was calculated according to the Cockcroft-Gault method. Patient characteristics: 15 elderly pts (median 78 range71–84yrs), 6 younger pts (median 50.5 range 43–57yrs); 9 (42.9%) males and 12 (57.1%) females; median KPS 90 (range 70–100); 8 MBC pts (38%), 13 CRC pts (62%). Blood samples were taken on the first day of treatment at time 0 and at 0.25,0.5,1,2,3,4,5,6,8 hrs after the first drug administration and on 4th, 8th, 12th and 14th days in the morning. Plasma levels of Cape, 5DFUR, 5DFCR and 5FU were determined by a validated HPLC method and UV detection. Results: At present PK data after the first administration of Cape are available for 13 pts (9 elderly; 4 younger). The mean Cape and 5DFCR AUC0–8hr are higher in older patients (Cape 6653±2564.8 vs. 4427±2714.5; P=0.09; 5DFCR 8635±5197.1 vs. 6292±3813.6; P=0.26), while no evident differences are present for 5DFUR and 5FU. The same results are obtained both in pts with CrCl < and ≥ 50 ml/min. The ratios of DFUR_AUC to Cape_AUC and 5FU_AUC to Cape_AUC are conversely higher in younger than in older pts (mean: 2.2 vs 1.62). A large interindividual variability in the concentration/time curves is present for Cape and metabolites. Cape dose reduction because of G3 toxicity (2 hand-foot syndrome, 1 stomatitis) was performed in 3 elderly pts. Drug systemic exposure was higher in 2 of these pts independently of CrCl. Conclusions: The preliminary results of this PK study suggest that elderly patients treated with Cape at 1000 mg/sm/bid are more drug-exposed than younger patients, independently of renal function. PK analysis is ongoing for the remaining patients.

No significant financial relationships to disclose.

Stop-flow technique for loco-regional delivery of high dose chemotherapy in the treatment of advanced pelvic cancers

AIM

To verify the rationale of a pelvic stop-flow technique for the perfusion of high-doses of mitomycin C and anthacyclines in patients with inoperable, recurrent pelvic cancer.

METHODS

The stop-flow technique was realized by using percutaneous double-balloon arterial-venous catheters that selectively isolate the pelvic vascular section and a perfusion provided by an extracorporeal pump for 20 min. Ten patients (pts) with unresectable pelvic recurrence from colon-rectal cancer were treated with a combination of Mitomycin C (MMC, 20 mg/sqm) plus doxorubicin (DOXO, 75 mg/sqm; 8pts) or epirubicin (EPI, 75 mg/sqm; 2pts) infused into the isolated pelvic compartment. Blood samples were collected from the extracorporeal vascular flow and from peripheral plasma, and analysed for drug quantitation.

RESULTS

During the procedure, there were no technical or hemodynamic complications, and no deaths occurred during surgery or in the postoperative period. MMC and DOXO peak levels measured in the extracorporeal system which irrotates the tumor area, were on average 21.6 (range: 4.3-44.3, MMC) and 17.2 (range: 1.8-48.4, DOXO) times higher than those observed in the peripheral blood. Similarly; the area under concentration (AUC) versus time curves measured in the pelvic compartment during stop-flow perfusion were 19.9 (range: 3.8-45.0, MMC) and 13.4 (range: 1.2-26.6, DOXO) times higher than the corresponding value in peripheral circulation. The drug percentage eliminated in the ultra filtrate was only 7.7% (MMC) and 0.9% (DOXO), and the plasmatic AUC(0-24) were similar to those observed with iv bolus of equivalent drug doses. Minimal systemic and local toxicities were observed. One complete pathological and 2 partial responses were observed; pain remission in 8/10 patients. median survival was 12 months (8-31).

CONCLUSION

The endo-arterial administration into the local vasculature produces high pelvic-systemic concentration gradients during the stop-flow perfusion with limited local and systemic toxicity. The encouraging clinical results suggest further evaluation.

New challenges and old problems: end of life care and the dilemma of prognostic accuracy

Dignity of the natural end of life for everybody is one of the new great challenges of medicine and social care for the beginning 21st century. However, many end of life care providing doctors are confused about how to categorize the help they give. One of the central problems is predicting the life expectancy of an individual patient. Difficulties in this field can become ethical dilemmas when physicians are obliged to predict accurately a patient's prognosis as the basis for a certain care strategy. Clinical estimation of the duration of life for patients with end of life cancer needs experience and training. Education programmes in the field should include this topic much more until now. Prognosis should be based more on proven indices and less on intuition. However, there is no doubt that daily clinical practice limits the use of highly sophisticated computer-based score models. Even maximal accuracy of prognosis will not exclude the risk of errors in a great part of patients. This limits their classification in care categories too strictly defined. Health care systems should avoid models for care with standards and budgets based on prognostic estimates and the medical community should avoid claim by disciplines of certain categories of patients defined by their prognoses. What we need is a network of assistance for incurable patients with single parts defined by patients needs and not by predicted life expectancy. Separating palliative and terminal care is artificial and often in contrast to the needs of the patients.

Acute self-limiting jejunitis as the first manifestation of microscopic polyangiitis associated with Sjogren's disease: report of one case and review of the literature

We report a case of acute self-limiting ulcerative jejunitis of unknown aetiology in a 72-year-old female patient in which a subsequent diagnosis of microscopic polyangiitis and Sjogren's syndrome was made. All known causes of jejunal ulceration and inflammation were excluded. Previously reported cases of acute self-limiting jejunitis are reviewed and the possibility that acute jejunitis in this patient had been the first manifestation of systemic vasculitis is discussed.

Advanced ovarian cancer patients with no evidence of disease after platinum-based chemotherapy: retrospective analysis of the role of second-look

From 1981 to 1992, 230 previously chemotherapy-untreated epithelial ovarian cancer patients (Stages IIb-III or IV) received platinum-based polychemotherapy at our Division. In this presentation, time to progression and overall survival rates were retrospectively analyzed in 89 epithelial ovarian cancer patients (stage IIb, c - III or IV) with no clinical evidence of disease (clinical complete remission--CCR--in 26 patients with postsurgical residual tumor > or = 2 cm, and no clinical evidence of disease--NED--in 63 patients with post-surgical residual tumor < 2 cm) after first-line platinum-containing chemotherapy. After at least 6 courses of chemotherapy, 62 patients (group A) were submitted to second-look (SL) laparotomy (n=47) or laparoscopy (n=15); 27 patients (group B) did not undergo second-look surgery because of patient refusal, the surgeon's decision or clinical contro-indications to surgery. Groups A and B were comparable in terms of post-surgical residual tumor (< 2 cm: 71% vs 70%), median Performance Status (WHO: 1) and median age (56 vs 57 yrs). FIGO stage IIb, c was more frequent in group B (26% vs 18%--p=0.004). In 9/18 (50%) patients with clinical CR and in 31/44 (70%) NED patients no residual tumor was confirmed at SL (pathological CR--pCR). After a median follow-up of 10 years (range 5-16 years), 72% (64/89) of patients relapsed and 65% (58/89) died. Survival was significantly longer in patients with pCR (median survival 76 months vs 32, 29 and 16 months for patients with pPR, pNC or pPD, respectively, p=0.0001). Multivariate analysis identifies pCR as the only significant prognostic factor exerting an influence on survival after second-look laparotomy (p=0.0000). This study confirms that the second-look can provide an important prognostic evaluation in patients without evidence of disease after chemotherapy for ovarian cancer stages III-IV.

A double-blind evaluation of the analgesic efficacy and toxicity of oral ketorolac and diclofenac in cancer pain. The TD/10 recordati Protocol Study Group

AIM

To compare the analgesic efficacy and toxicity of the nonsteroidal anti-inflammatory analgesic drug, ketorolac (Toradol, Recordati spa, Milan) 10 mg p.o. (t.i.d.) with diclofenac (Voltaren, Novartis Farma, Origglo, VA) 50 mg p.o. (t.i.d.) in cancer patients with moderate to severe chronic pain.

METHODS AND STUDY DESIGN

The study was a multicenter randomized double-blind cross-over trial. Each treatment lasted 7 days, after which the patients crossed over to the other drug. Pain intensity was evaluated by the visual analogue scale (VAS) after the first dose and by the 5-point verbal rating scale (VRS) by the patient and by the physician following the 7-day treatment.

RESULTS AND CONCLUSIONS

A total of 138 advanced cancer patients were enrolled in the study. Overall 251 single-dose administrations (117 cross-over observations) and 257 multiple treatments (127 cross-over experiments) were assessable. After a single administration of ketorolac and diclofenac, no significant difference could be observed in analgesic activity, as indicated by the area under the pain-intensity time curve (AUC0-8), in the maximum efficacy, or the duration of efficacy of the two drugs. The Westlake confidence intervals of the AUC0-8 ratio (ketorolac: diclofenac) (1.07; 90% CI, 0.94-1.19), of the maximum efficacy ratio (1.03; 90% CI, 0.92-1.14), and the duration of efficacy ratio (1.05; 90% CI, 0.97-1.11) showed the bioequivalence of the two drugs. Satisfactory pain relief was reported for multiple 7-day treatments, with no significant differences between the two therapies: according to the physician's evaluation, in 93/128 (73%; 95% CI, 65-80%) ketorolac treatments and 91/129 (71%; 95% CI, 63-78%) diclofenac treatments; according to the patient's evaluation, in 83/128 cases (65%; 95% CI, 57-73%) after ketorolac and in 74/129 cases (57%; 95% CI, 49-66%) after diclofenac. Adverse symptoms were acceptable with both drugs. Interestingly, a pronounced sequence effect was found: gastric disturbances after ketorolac were observed mainly (10 out of 15 observed events) when the drug was given to patients pretreated with diclofenac.

Multicenter randomized clinical trial on high-dose epirubicin plus cis-platinum versus vinorelbine plus cis-platinum in advanced non small cell lung cancer

BACKGROUND

High dose Epirubicin (HD-EPI) (>90 mg/m2) and Vinorelbine (VNR) demonstrated antitumor activity as single agent (about 20%) in the treatment of advanced NSCLC. This trial compares these two agents combined with cisplatin (CP).

PATIENTS AND METHODS

From August 1992 to February 1996, 228 patients with locally advanced or metastatic NSCLC were randomized to receive either EPI 120 mg/m2 as i.v. bolus plus Cisplatin (CP) 60 mg/m2 on day 1 (regimen A) or VNR 25 mg/m2 as i.v. bolus on day 1 and 8 plus CP 60 mg/m2 on day 1 (regimen B). Both treatments were recycled every 21 days up to a maximum cumulative dose of EPI of 840 mg/m2 or 12 cycles. Eligible patients were 212 and 198 patients were evaluable for objective response (95 in arm A and 103 in arm B). The main characteristics of eligible patients were: male/female 179/33; median age 61 (42-72); median Karnofsky PS 80 (70-100); stage IIIA 12%, stage IIIB 40%, stage IV 41%, recurrence 7%; histotype: epidermoid 48%, adenoca 36%, others 16%.

RESULTS

The following response rates were observed in regimens A and B, respectively; CR, 1 and 2%, PR, 32 and 25% (P = 0.4567). Median CR + PR duration was 9 and 8 months, respectively. Median survival was 10.5 and 9.6 months, respectively. Grade III-IV leucopenia occurred in 38 and 21% in arm A and arm B, respectively(P = 0.01), thrombocytopenia in 6 and 0% (P = 0.02), anemia in 8 and 7% (n.s.). Non-hematological toxicity was moderate and the only difference between the treatments was alopecia (88 vs. 33% in arm A and B, respectively). Supraventricular arrhythmia occurred in three patients on regimen A; a >15% LVEF absolute decrease was observed in 9 (22.5%) and three (14%) patients on arm A and arm B, respectively (n.s.). No congestive heart failure was observed.

CONCLUSION

HD-EPI+CP and VNR+CP are both active combinations in advanced NSCLC with a similar response rate, response duration and survival but regimen A was significantly more toxic (myelosuppression and alopecia).

Comparative crossover trial of two intravenous doses of granisetron (1 mg vs 3 mg) + dexamethasone in the prevention of acute cis-platinum-induced emesis

BACKGROUND

The 5HT3 receptor antagonist Granisetron (GRA) is available on the market as a 1 mg vial in USA and as a 3 mg vial in Europe. This study aimed to compare the two i.v. doses of GRA (3 mg vs 1 mg), both of which combined with Dexamethasone (DEX) (20 mg) in the prevention of acute Cisplatinum (CP)-induced emesis.

PATIENTS AND METHODS

One hundred and ninety-eight consecutive chemotherapy-naive cancer patients, mainly suffering from lung and bladder cancer, were randomized at their first cycle to receive either GRA 1 mg + DEX or GRA 3 mg + DEX as i.v. bolus prior to chemotherapy and crossed-over to another GRA dose at the second cycle. The cytotoxic treatment included different multi-drug regimens containing CP (median dose 60 mg/m2, range 50-70) administered on day 1 and repeated every 21-28 days.

RESULTS

Of the 192 evaluable patients complete protection from acute emesis with GRA 1 and GRA 3, was observed after the 1st + 2nd cycles as follows: nausea 70% and 74%, vomiting 90% and 94%, nausea and vomiting 67% and 74% respectively (no statistically significant difference). No carry-over effect was observed on the complete protection from emesis. The crossover analysis comprising 156 patients confirmed there were no differences between the two antiemetic treatments. Twenty-seven per cent of patients preferred GRA 1, 31% preferred GRA 3, while 42% expressed no preference (P = 0.75). Nor was any difference observed for tolerability, the only reported side-effects being mild headache (16% vs 17%) and constipation (18% vs 25%).

CONCLUSION

This study shows that, under the above conditions, the 1 mg and 3 mg i.v. GRA doses are comparably effective when combined with DEX 20 mg in the prevention of acute CP-induced emesis.

Thromboxane antagonism and cough induced by angiotensin-converting-enzyme inhibitor

BACKGROUND

The increased prostaglandin synthesis that might follow stimulation of the arachidonic acid cascade by angiotensin-converting-enzyme inhibition (ACE-I) has been suggested to underlie the appearance of cough on ACE-I treatment. We investigated whether the prostanoid thromboxane was involved.

METHODS

Nine patients with essential hypertension who had cough after enalapril 20 mg once a day (coughers) were treated, while continuing the enalapril, in a double-blind crossover study with placebo or picotamide, 600 mg twice daily. Picotamide is a platelet antiaggregant that acts through both inhibition of thromboxane synthase and thromboxane-receptor antagonism. Thirteen hypertensive patients with no history of ACE-I-induced cough were also treated with enalapril and served as controls. Cough frequency was measured by a visual analogue scale and by a daily cough diary. 24 h urinary recovery of 11-dehydro-thromboxane-B2 and 6-keto-PGF1 alpha were measured to assess any changes in endoperoxide metabolism during the study periods.

FINDINGS

11-dehydro-thromboxane-B2 (TXB2) recovery was significantly reduced by picotamide, which led to the disappearance of cough in eight patients within 72 h. Picotamide urinary recovery data suggested incomplete absorption in the non-responder. At baseline and after rechallenge with enalapril, 11-dehydro-TXB2 excretion was in the same range in the controls and in the coughers, but the latter showed significantly lower excretion of 6-keto-PGF1 alpha, and their ratio of 11-dehydroTXB2 to 6-keto-PGF1 alpha was twice that of the controls (1.40 [95% CI 0.86-1.95] vs 0.61 [0.37-0.84]).

INTERPRETATION

A thromboxane antagonist is effective in ACE-I-induced cough. An imbalance between thromboxane and prostacyclin may represent a marker of patients susceptible to ACE-I-induced cough.

Pseudoxanthoma elasticum: a rare cause of gastrointestinal bleeding

Pseudoxanthoma elasticum (PXE) is a rare connective tissue disorder. The main clinical features of this condition are characteristic skin lesions, angioid streaks of the fundus oculi, and occlusive vascular disease. Gastric hemorrhage is a rare complication. A gastroscopic examination was performed on two patients with PXE who presented with upper gastrointestinal tract bleeding. The two patients had submucosal yellowish nodular lesions similar to the xanthoma-like skin lesions seen in the disease. We suggest that a diagnosis of PXE be considered for any patient with gastrointestinal hemorrhage, especially if routine clinical and endoscopic examination fail to reveal the cause, and if raised yellow plaque-like lesions are seen in the stomach by endoscopy.

An open randomised cross-over study on granisetron versus ondansetron in the prevention of acute emesis induced by moderate dose cisplatin-containing regimens

The aim of the study was to compare granisetron (GRA) with ondansetron (OND) in the prevention of acute emesis in consecutive chemotherapy-naive patients admitted to our department to receive a cytotoxic treatment containing cisplatinum (CP) at a dose > or = 50 mg/m2. Eligible patients were randomised at their first cycle to receive either OND or GRA with cross-over of the anti-emetic treatment on the second cycle. The cytotoxic treatments included five different multidrug regimens containing CP (median dose 60 mg/m2, range 50-70 mg/m2) administered on day 1 and repeated every 21-28 days. OND was administered at the dose of 8 mg x 3 i.v. on day 1 and 8 mg x 2 orally on day 2. GRA was always administered at the dose of 3 mg i.v. on day 1. 124 patients entered the study. 58 patients received OND at their first cycle and 66 received GRA. Complete protection of acute emesis with OND and GRA was observed, with the first and second cycles combined as follows: nausea 53 and 60%, vomiting 68 and 71%, respectively (no statistically significant difference). The cross-over analysis comprising 101 patients confirmed no difference between the two anti-emetic treatments. 21 patients (19%) on OND and 14 patients (12%) on GRA suffered headaches (P = 0.15). 25 (25%) patients preferred OND, 45 (45%) preferred GRA, while 31 (30%) expressed no preference (P = 0.003). However, these differences also depended on the sequence of anti-emetics in the cross-over. In conclusion, in this study, a single dose of GRA is demonstrated to be as effective as multiple doses of OND in the prevention of acute emesis.

CEA, MCA, CA 15.3 and CA 549 and their combinations in expressing and monitoring metastatic breast cancer: a prospective comparative study

Serum levels of carcinoembryonic antigen (CEA), mucin-like carcinoma-associated antigen (MCA), CA 15.3 and CA 549 were concurrently assayed in patients with metastatic breast cancer. Overall sensitivity in detecting metastatic breast cancer (201 pts) was CEA 45%, MCA 59%, CA 15.3 71% and CA 549 72% (P < 0.01). Sensitivity increased by only 6% to 8% when two or more antigens were simultaneously considered. An overall sensitivity of correlation with objective response (n = 71) was observed in the range of 53-67% (P = n.s.) in patients with abnormal baseline marker values, and in the range of 42-87% (P < 0.05) in patients with normal baseline values. The combination of two or more markers did not improve sensitivity, but decreased specificity of correlation with objective response. In conclusion, CA 15.3 and CA 549 have individually higher sensitivity in detecting metastatic breast cancer. No clinical advantage was observed for using two or more markers concurrently over CA 15.3 or CA 549 alone in the monitoring of metastatic breast cancer.

Pharmacokinetic evaluation of two different formulations of megestrol acetate in patients with advanced malignancies

The bioequivalence of two megestrol acetate formulations, 160-mg "tablets" and 160-mg "sachets," was investigated in a single-dose, open-label, balanced-for-sequence cross-over study involving 12 advanced-cancer patients. The observed plasma megestrol-acetate time course obtained with both formulations was consistent with the literature data. The main source of variability in the pharmacokinetic parameters was intersubject variability; drug formulation played only a minor (and nonsignificant) role. The width of the 90% confidence interval of the area-under-the-curve (AUC) ratio (sachets: tablets) computed according to Schuirmann (0.9-1.4) was mainly due to the presence of a single outlier, showing an AUC ratio of 2.7. The trend to higher bioavailability of the new formulation was not significant, especially as compared with the dose-response data reported in the literature.

Aminoglutethimide in advanced breast cancer: prospective, randomized comparison of two dose levels. Italian Cooperative Group

In a multicenter randomized clinical trial 106 post-menopausal patients with progressive metastatic breast cancer were allocated to receive 500 mg or 1000 mg Aminoglutethimide (AG) per os daily. Cortisone Acetate (CA) replacement dose was 37.5 mg/day orally in both groups. In 91 fully evaluable patients, no statistically significant difference was observed between the two therapeutic regimens, neither in terms of overall response (28 vs 35%) and by site responses, nor in terms of median time to progression (10.5 vs 14.5 months) and median overall survival (20 vs. 22 months). The tolerability was satisfactory in both regimens. Although no statistically significant differences occurred, in the low dose regimen we observed fewer patients with side-effects (25% vs 6%) and induced grade 3 side-effects (4% vs 9%). Our results confirm that AG daily doses of 500 and 1000 mg associated with corticosteroids have a comparable effect. Because of its slight but clinically noticeable better tolerability, the lower dose is the preferable regimen in the treatment of advanced breast cancer.

Epirubicin metabolism and pharmacokinetics after conventional- and high-dose intravenous administration: a cross-over study

In a pharmacokinetics study, six patients were treated i.v. with epirubicin (EPI) at the two dose levels of 60 and 120 mg/m2, whereas a further six patients were treated at 75 and 150 mg/m2. Both groups were studied according to a balanced cross-over design; the aim of the study was to assess the pharmacokinetic linearity of epirubicin given at high doses. Both the absolute goodness of fit and the Akaike Information Criterion (AIC) point to a linear, tricompartmental open model as the choice framework for discussing EPI plasma disposition after 16/24 administrations, independent of the delivered dose. After 8 treatments, the minimal AIC value corresponded to a nonlinear tissue-binding model. However, even in these cases, second-order effects were present only during the early minutes following treatment. In a model-independent framework, mean EPI plasma clearance was identical at the two dose levels of 60 and 120 mg/m2 (65.4 +/- 8.0 vs 65.3 +/- 13.4 l/h, P = 0.92). Both the mean residence time (MRT) and the volume of distribution at steady-state (VSS) were similar as well (MRT: 22.6 +/- 2.9 vs 24.2 +/- 3.7 h; P = 0.46; VSS: 21.3 +/- 1.5 vs 22.6 +/- 6.5 l/kg, P = 0.46). No statistically significant difference could be found in mean statistical-moment-theory parameters determined after 75- and 150-mg/m2 EPI doses (plasma clearance, PlCl: 83.4 +/- 13.5 vs 68.5 +/- 12.8 l/h, P = 0.12; MRT: 22.6 +/- 4.8 vs 21.9 +/- 3.9 h, P = 0.60; VSS: 26.7 +/- 10.5 vs 21.2 +/- 7.0 l/kg, P = 0.17). Analysis of variance also failed to reveal any significant correlation between dose and plasma clearance. However, when data relative to single patients were examined, a trend toward nonlinear drug distribution as well as a consequent increase in peripheral bioavailability could be observed in 4/6 patients of the 75-mg/m2 vs the 150-mg/m2 group.(ABSTRACT TRUNCATED AT 400 WORDS)

ACE inhibition in diabetic patients: effect on pressor responsiveness to noradrenaline

The pressor responsiveness to noradrenaline was assessed before and after four weeks of treatment with enalapril (20 mg/day) in eight mild-to-moderate essential hypertensives, in eight normotensive type II diabetics and in eight mild-to-moderate hypertensive type II diabetic patients. The ACE inhibitor interfered to the same extent with the renin-angiotensin system and did not alter noradrenaline kinetics in the three groups of patients, but significantly reduced the arterial responsiveness only in non-diabetic subjects. It is suggested that factors, such as an exaggerated sodium retention, might determine the lack of effect of enalapril in diabetic patients.

Idarubicin metabolism and pharmacokinetics after intravenous and oral administration in cancer patients: a crossover study

The pharmacokinetics and metabolism of 4-demethoxydaunorubicin (idarubicin, IDA) were studied in 21 patients with advanced cancer after i.v. (12 mg/m2) and oral (30-35 mg/m2) treatment according to a balanced crossover design. Patients were divided into four groups: subjects who showed normal liver and kidney function (group N), those who presented with normal kidney function and liver metastases (group L), those with kidney dysfunction (creatinine clearance, less than or equal to 60 l/h; group R), and those with both liver and kidney dysfunction (group LR). Five patients showed variations in liver or kidney function after the first treatment and were considered to be nonevaluable for the crossover study but evaluable for the liver/kidney function study; some of them appeared in different groups for the i.v. as opposed to p.o. treatments. After i.v. administration, IDA plasma levels followed a triphasic decay pattern. The main metabolite observed in all patients was the 13C-reduced compound (IDAol), which attained plasma levels 2-12 times higher than those of the parent compound. IDA pharmacokinetics was not dependent on the presence of liver metastases but was related to the integrity of kidney function. Analysis of variance indicated a significant correlation between IDA plasma clearance and creatinine clearance; it was also found that IDA plasma clearance was lower in patients whose creatinine clearance was less than 60 ml/min [group N, 122.8 +/- 44.0 l/h; group L, 104.4 +/- 27.7 l/h (P = 0.58) vs group R, 83.4 +/- 18.3 l/h (P = 0.037)]. The IDAol terminal half-life and mean residence time (MRT) were significantly increased in patients with impaired kidney function [MRT: group N, 63.6 +/- 10.8 h; group L, 69.9 +/- 10.2 h (P = 0.27) vs group R, 83.2 +/- 10.9 h (P = 0.025) and t1/2 gamma: group N, 41.3 +/- 10.1 h; group L, 47.0 +/- 7.4 h (P = 0.31) vs group R, 55.8 +/- 8.2 h (P = 0.025)]. After oral treatment, drug absorption occurred during in the first 2-4 h after IDA administration; a biphasic decay pattern was observed thereafter. The main metabolite observed in all patients was again IDAol. The AUC of IDAol was greater after oral administration than after i.v. treatment in proportion to the AUC of IDA (i.v.: AUC-IDAol/AUC-IDA, 2.4-18.9; p.o.: AUC-IDAol/AUC-IDA, 4.1-21.4). Following oral dosing, a substantial amount of 4-demethoxydaunomycinone (AG1) was found in 11/21 patients.(ABSTRACT TRUNCATED AT 400 WORDS)

High-performance liquid chromatographic analysis of idarubicin and fluorescent metabolites in biological fluids

A specific, sensitive, and reliable high-performance liquid chromatographic (HPLC) method for the determination of idarubicin (IDA) and its known fluorescent metabolites idarubicinol (IDAol) and 4-demethoxy-daunomycinone (AG1) in biological fluids (human plasma and urine) was developed and tested. Plasma samples were solid-phase-extracted (C18 bonded silica cartridges). Complete separation of unchanged drugs and metabolites was achieved on a Cyanopropyl chromatographic column (25 cm x 4.6 mm inside diameter; particle size, 5 microns) using fluorescence detection (excitation wavelength, 470 nm; emission wavelength, 580 nm). Sensitivity was better than 0.2 ng/ml for all analytes; rates of recovery of unchanged drug and metabolites were better than 84.5% (IDA), 80.3% (IDAol), and 83.9% (AG1). The interassay coefficient of variation was 6.5% for IDA, 5.8% for IDAol, and 9.8% for AG1. Mean intra-assay precision was 4.6% for IDA, 5.9% for IDAol, and 5.0% for AG1 at sample concentrations of above 1 ng/ml and 12.1% for IDA, 10.8% for IDAol, and 14.1% for AG1 at sample concentrations of below 1 ng/ml.

Efficacy and tolerability of enalapril (20 mg)/hydrochlorothiazide (12.5 mg) combination therapy in essential hypertension

The efficacy and tolerability of a preconstituted formulation combining enalapril (20 mg) and hydrochlorothiazide (12.5 mg) were evaluated in patients with essential hypertension unresponsive to enalapril monotherapy (20 mg/day). The duration of this open-lable, multicenter, noncomparative trial was 12 weeks: a two-week washout period followed by ten weeks of active treatment. During the active treatment period, patients received enalapril alone (up to 20 mg/day) for six weeks. At the end of week 6, patients with supine diastolic blood pressure greater than 90 mmHg were treated with the enalapril/hydrochlorothiazide combination therapy (EN/HCTZ). Of the 147 patients who were entered into the study, 81 were not normalized with enalapril alone. At the end of the study period, blood pressure was normalized (supine diastolic blood pressure less than or equal to 90 mmHg) in 60 (74%) of the 81 patients who had received the EN/HCTZ combination. Overall, 86% of the patients achieved satisfactory blood pressure control with this therapeutic regimen. Adverse reactions were mild and transient. Six patients experienced undesirable effects, the most frequent of which was coughing (2 cases). Neither enalapril (20 mg/day) alone nor the EN/HCTZ combination had any significant influence on any of the metabolic parameters evaluated. No hypokalemia and no significant changes in serum lipids occurred in the course of the study.

Flecainide: evidence of non-linear kinetics

The pharmacokinetics of flecainide has been studied in 12 patients with ventricular arrhythmias, both after single administration and during chronic treatment. Both the half-life and the AUC were significantly increased during chronic treatment. This suggests that the kinetics of flecainide might be non-linear also in patients with normal kidney and liver function. The increase in plasma flecainide levels during chronic treatment could not be predicted, so close monitoring of its plasma levels is advisable.

Pharmacokinetics of a controlled release preparation of naproxen

The pharmacokinetics of a controlled release preparation of naproxen (750 mg) was compared with that of standard release naproxen, in 12 healthy volunteers. The plasma levels of naproxen and urinary recoveries of naproxen and metabolites were determined both after single doses and chronic administration. The experimental data show that the bioavailability of the controlled release preparation is equal to that of standard release naproxen; however, the controlled release preparation allows more constant plasma levels of naproxen and, when administered once a day for prolonged periods, is capable of maintaining effective concentrations for most of the dosing period.

[Significance of the degree of oxidative hepatic metabolism in conditioning the pharmacokinetics and the pharmacodynamics of propafenone]

The aim of this study was to evaluate plasma concentrations of propafenone (P) and 5-hydroxy-propafenone (5-OH-P) at steady state in 36 patients with ventricular premature beats, Lown class greater than or equal to 2, submitted to antiarrhythmic treatment with propafenone either in acute administration (AA) (300-450 mg) or in chronic administration (CA) (150-300 mg t.i.d. for 14-21 days followed by a wash out), and to define the relationship existing between metabolic oxidative capacity and P and 5-OH-P pharmacokinetics and pharmacodynamics. Antiarrhythmic treatment resulted efficacious in 31/36 cases (86%) during AA and in 28/36 cases (78%) during CA. At steady state a wide interindividual variability was observed in plasma concentrations of P (mean = 835 +/- 619 ng/ml, coefficient of variation = 74%), in plasma concentrations of 5-OH-P (mean = 142 +/- 93 ng/ml, coefficient of variation = 65%) and of their ratio (mean = 6.51 +/- 8.53, coefficient of variation = 131%), without significant differences between responders and nonresponders. In a subgroup of 14 subjects, characterized as extensive oxidizers of dbrisoquine, a significant correlation (r = 0.97, p less than 0.001) was observed between the ratio of P and 5-OH-P plasma concentrations at steady state and oxidative metabolic capacity (expressed as debrisoquine/4-hydroxy-debrisoquine ratio). Oxidative metabolic capacity was also correlated with P half life (r = 0.82, p less than 0.002 in AA and in CA) and with the ratio of P and 5-OH-P area under curve (r = 0.91, p less than 0.001 in AA and r = 0.90) changes at the electrocardiogram (mean values = + 20% for QRS, +26% for PR). In conclusion, oxidative metabolic pathway is a crucial point in propafenone metabolization; indeed the extent of metabolic oxidative capacity, evaluable by analysis of debrisoquine oxidation, is responsible for a wide interindividual variability of P and 5-OH-P plasma concentrations, present even in a population of debrisoquine extensive oxidizers and, moreover, influences the extent of electrocardiographic changes of PR and QRS intervals, which are related to 5-OH-P plasma levels, but not to P plasma levels.

The effect of ace inhibition on peripheral hemodynamics in normotensive and hypertensive patients with type II diabetes

The effect of treatment with enalapril (10 days at 10 mg/d followed by 4 weeks at 20 mg/d) on forearm hemodynamics was assessed in eight normotensive patients and eight patients with hypertension affected by Type II diabetes as well as in eight patients with essential hypertension and normal glucose tolerance. The ACE inhibitor decreased regional vascular resistances and increased the maximum arteriolar-vasodilating capacity and venous distensibility in the three groups of patients. Thus, this study shows that ACE inhibition by enalapril improves regional hemodynamics in patients with Type II diabetes.

Aminoglutethimide in advanced breast cancer: plasma levels and clinical results after low and high doses

Drug plasma levels, metabolism data and clinical results were evaluated after the daily administration of either 500 or 1,000 mg aminoglutethimide (AG, Orimeten, Ciba-Geigy) plus hydrocortisone acetate (20 mg b. i. d.). A total of 34 patients with advanced breast cancer entered the study: 17 were given 1,000 mg/day and 17 received 500 mg/day for at least 3 months. A novel HPLC method was developed to determine the levels of AG and its known metabolites [N-acetyl-AG (NAG), formyl-AG, nitroglutethimide, hydroxy-AG] in the biological samples. AG plasma concentration was significantly higher during the 1,000-mg/day regimen. NAG was the only metabolite observed in plasma, always occurring at concentrations lower than those of the parent drug. The ratios between NAG and AG levels distinguish two statistically different groups of patients. Irrespective of the dose, a partial response was observed in 44% of the patients; no change in 32% of cases; and progressive disease had an incidence of 24%. The probability of response was not dependent on the drug AUC or on the NAG/AG ratio and did not significantly depend on previous hormone treatment. Neither the plasmatic level of the AG or metabolite concentrations nor the NAG/AG ratio seemed to affect the incidence of side effects.

Angiotensin converting enzyme inhibitors, thiazide diuretics and magnesium balance. A preliminary study

Serum and mononuclear cell magnesium content were determined in a cross-sectional study performed in four groups of hypertensive patients on chronic treatment with atenolol (n = 11), enalapril (n = 10), thiazide diuretics (n = 12), or enalapril + thiazides (n = 11). Our study shows that in patients treated with the thiazides alone, in spite of normal serum potassium and magnesium levels, mononuclear cell magnesium was decreased. To the extent that mononuclear Mg content mirrors the body ion stores, our results indicate that thiazides induce a Mg depletion not detectable by monitoring serum levels.

ACE inhibition and pressor responsiveness to norepinephrine in hypertensive patients

The pressor response to norepinephrine (NE) was assessed in normal renin essential hypertensive patients before and after they were randomly assigned to receive in parallel groups of treatment a single dose of an angiotensin converting enzyme (ACE) inhibitor (captopril or lisinopril) or a prolonged therapy with lisinopril (30-45 days) or with hydrochlorothiazide (9 days). Blood pressure was significantly reduced by all treatments. The pressor response to NE was unchanged after the single administration of the ACE inhibitors, while it was blunted after chronic administration of lisinopril and after the diuretic. On the basis of these results, it is suggested that the attenuation of the sympathetically mediated vasoconstriction may represent an additional mechanism contributing to the antihypertensive effect of ACE inhibitors administered chronically.

Minimal effective concentration values of propafenone and 5-hydroxy-propafenone in acute and chronic therapy

We evaluated the antiarrhythmic efficacy and the minimal effective concentrations of propafenone and its metabolite 5-hydroxy-propafenone during a) acute intravenous infusion (1.5 mg/kg in bolus followed by 45 minutes infusion), b) an acute oral single-dose test (450 mg), and c) 14-day chronic therapy (300 mg tid) followed by a washout. Oxidative metabolism was assessed by a debrisoquine oral test in every patient. Eleven patients with stable ventricular premature beats (VPBs) greater than or equal to 300/hr and Lown class greater than or equal to 3 completed the study. The main results emphasized a certain discrepancy between the clinical effect of the acute intravenous infusion (efficacy in 5 out of 11 patients) and of the acute oral test and chronic therapy (efficacy in 11/11), with a time lag of the ECG changes during the acute intravenous infusion. The minimal effective concentrations were lower after acute oral administration compared with chronic treatment both for propafenone (200 +/- 189 ng/ml vs. 492 +/- 530 ng/ml; p less than 0.05) and for 5-hydroxy-propafenone (82 +/- 40 ng/ml vs. 149 +/- 80 ng/ml; p less than 0.02). A linear correlation was demonstrated between drug/metabolite ratios of propafenone and debrisoquine, either after acute oral (r = 0.91) or after chronic administration (r = 0.84). The pharmacokinetics of propafenone was nonlinear and showed wide interindividual variations.(ABSTRACT TRUNCATED AT 250 WORDS)

[Determination of oxidative phenotype in a sample population and correlation with the pharmacokinetics of propafenone]

Propafenone, like other cardioactive drugs (metoprolol, propranolol, encainide) is submitted to oxidative metabolism, evaluable by assessment of debrisoquine oxidative capacity. Two phenotypes have been described: extensive and poor oxidizers, with interethnic differences in the prevalence of poor oxidizers. Aims of this study were: 1) to assess the oxidative phenotype in a sample of the Italian population and 2) to evaluate the relationships between oxidative capacity and propafenone pharmacokinetics or pharmacodynamics. The ratio between debrisoquine (D) and 4-hydroxy-debrisoquine (4-OH-D) in the urines after D administration (10 mg) was employed to characterize oxidative phenotype in 90 subjects (42 arrhythmia patients and 48 healthy volunteers). In 10 patients, extensive oxidizers of debrisoquine, we studied propafenone (P) and 5-hydroxy-propafenone (5-OH-P) kinetics after acute oral administration (450 mg) and chronic oral treatment (300 mg tid for 2 weeks), followed by wash out.

RESULTS

1) the prevalence of poor oxidizers (D/4-OH-D ratio greater than 12.6) in our population resulted to be 6.6%, like in other studies in Caucasians; 2) propafenone kinetics was strictly related to oxidative capacity since D/4-OH-D ratio strictly correlated with the ratio of P and 5-OH-P areas under curve in acute (r = 0.91) and in chronic administration (r = 0.90) and with P half-life in acute (r = 0.82) and in chronic administration (r = 0.82); 3) QRS widening both during chronic treatment and after acute administration correlated with oxidative capacity (r = -0.78 and -0.68 with D/4-OH-D ratio respectively) and with 5-OH-P areas under curve (r = 0.84 and 0.70 respectively); it did not correlate with P areas under curve. In conclusion both kinetics and electrophysiological effects of propafenone strictly correlate with oxidative capacity, even in extensive oxidizers. Thus even a small reduction in oxidative capacity may have relevant consequences during propafenone oral treatment.

Pharmacokinetics of heparin and low molecular weight heparins

The main kinetic features of heparin and low molecular weight heparins (LMWHs) are reviewed. The complexities related to the study of a nonhomogeneous drug containing fractions with different molecular weight and pharmacological effects are discussed along with the possible bias due to the prevalent use of indirect measures of drug concentration. Available data show that LMWHs have longer half-lives with respect to that of heparin and higher bioavailabilities after subcutaneous administration; experimental and clinical evidences suggest that the kinetics of heparin and LMWHs can only be described taking into account the presence of an endogenous pool from which these drugs are released with different speeds and after various types of manipulations.