Extended-release metoprolol succinate in chronic heart failure

OBJECTIVE

To review the pharmacology, pharmacokinetics, efficacy, and tolerability of extended-release (ER) metoprolol succinate and its role in the management of chronic heart failure.

DATA SOURCES

A MEDLINE search of English-language literature (1990-October 2002) was conducted using congestive heart failure and metoprolol CR/XL or metoprolol CR/ZOK as search terms to identify pertinent studies.

STUDY SELECTION/DATA EXTRACTION

All of the articles identified from the data sources were evaluated, with priority given to randomized, double-blind, placebo-controlled studies.

DATA SYNTHESIS

ER metoprolol succinate is a controlled-release tablet designed to produce even and consistent beta(1)-blockade throughout the 24-hour dosing interval, with less fluctuation in metoprolol plasma concentrations compared with immediate-release metoprolol. Three randomized, double-blind, placebo-controlled trials have evaluated the efficacy of ER metoprolol succinate in the treatment of patients with chronic heart failure. The MERIT-HF (Metoprolol CR/XL Randomized Intervention Trial in Congestive Heart Failure) study, the largest of these trials and the largest randomized mortality trial with beta-blockers in heart failure to date, demonstrated that ER metoprolol succinate reduced the relative risk of all-cause mortality by 34% versus placebo. Furthermore, the relative risk of the combined endpoint of mortality plus all-cause hospitalizations was reduced by 19% and sudden death was reduced by 41%. The benefits of therapy were evident in various patient subgroups, including elderly patients and those with diabetes mellitus. ER metoprolol succinate was generally well tolerated, with a similar proportion of patients discontinuing therapy due to adverse events relative to placebo (9.8% and 11.7%, respectively).

CONCLUSIONS

ER metoprolol succinate therapy provides substantial mortality and morbidity benefits in patients with New York Heart Association class II and III heart failure who are stabilized on angiotensin-converting enzyme inhibitors and diuretics. ER metoprolol succinate is administered once daily, is well tolerated, and provides consistent beta(1)-blockade over the 24-hour dosing interval.

Probing depth changes following 2 years of periodontal maintenance therapy including adjunctive controlled release of chlorhexidine

BACKGROUND

Multicenter clinical trials have established that the adjunctive use of the subgingival controlled release of chlorhexidine, (CHX chip), significantly reduces probing depth (PD), improves clinical attachment levels, and reduces bleeding on probing compared to scaling and root planing (SRP) alone for periods of up to 9 months. The present report is based on a phase IV clinical trial to examine the adjunctive use of the CHX chip for routine periodontal maintenance therapy (RPMT) over 2 years.

METHODS

Eight hundred thirty-five (835) patients were recruited into the study. At baseline a CHX chip was placed in pocket sites with PD > or = 5 mm. The patients were scheduled to receive RPMT at 3-month intervals with repeated CHX chip placement at sites where the PD remained > or = 5 mm. Patients who did not attend the 24-month recall visit or who failed to attend 2 consecutive time frame examinations were excluded from the analyses.

RESULTS

The 595 patients included showed a continuous decrease in PD over 2 years of 0.95 mm. After 2 years, 23.2% of patients had at least 2 pockets showing a reduction in PD of 2 mm or more and 58.9% of the sites had been reduced to a PD of < 5 mm. Only 2.9% (n = 57) of the sites showed an increase in PD of > or = 2 mm. Adverse events were mild to moderate in nature and resolved spontaneously without medication.

CONCLUSION

The results of this Phase IV or follow-up trial indicate that the adjunctive use of the CHX chip is a clinically safe and effective treatment option for long-term management of chronic periodontitis.

Replacement of conventional glucocorticoids by oral pH-modified release budesonide in active and inactive Crohn's disease: results of an open, prospective, multicenter trial

Glucocorticosteroids (GCS) are established in the treatment of active Crohn's ileitis and ileocolitis. Recently, the topical steroid budesonide was found to be effective in untreated patients with Crohn's disease (CD) causing less side effects than conventional GCS. No clinical data have been reported about the effects of switching from conventional GCS to budesonide in terms of side effects and disease activity. The primary aim of this study was to evaluate the development of side effects after switching from conventional GCS treatment to Eudragit L-coated budesonide (pH-modified release formulation) in patients taking 5-30 mg prednisolone equivalent per day for at least two weeks. In all, 178 patients with active CD (N = 88) or CD in remission during GCS treatment (N = 90) were included. Conventional GCS treatment was tapered down during a maximum of three weeks, with simultaneous intake of 3 x 3 mg budesonide. Thereafter, patients received 3 x 3 mg budesonide alone for six weeks. GCS-related side effects, disease activity and adverse events were documented at study entry and after 0, 2, 4, and 6 weeks of budesonide treatment. The percentage of patients with GCS-related side effects decreased from 65.2% (intention-to-treat-population) at entry to 43.3% (P < 0.0001) at the end of the trial. The total number of GCS-related side effects decreased significantly from 269 to 90. Of the patients who entered the study with active disease under conventional GCS therapy, 38.6% were in remission at the end of the study. Of the patients who entered the study with CD in remission, 78% stayed in remission after switching from conventinal GCS to budesonide. In conclusion, switching from conventional GCS treatment to budesonide leads to a significant reduction of GCS related side effects in patients with CD without causing rapid deterioration of the disease.

[Smoking cessation program based on pharmacological support (bupropion SR). Our own experience]

Smoking constitutes the gravest, yet avoidable, deadly threat to health in Poland. Near the end of the 90-ies it was discovered that the antidepressant -bupropion- has positive effects in the treatment of addiction to nicotine. The aim of the study was the evaluation of the efficacy of ambulatory, intensive smoking cessation program based on bupropion SR with educational support. 54 smokers (18 men and 36 women) were enrolled, age 22-59 yr. (mean 45.5 +/- 8.7), smoking 10-50 cigarettes daily. Early abstinence rate (7 weeks after quitting) was 61.1%, after 6 months 45.2% of the participants were still non-smokers. The most common adverse effects of bupropion SR therapy were mouth dryness and sleep disturbances, 13% of patients had to stop using bupropion because of side effects. High percentage of abstinence indicates that intensive smoking cessation programs should be used as a part of antinicotine strategy. The pharmacological support in the nicotine dependence treatment should be performed under careful physician supervision.

Efficacy and tolerability of extended-interval aminoglycoside administration in pediatric patients

Aminoglycosides are commonly used to treat serious Gram-negative infections in pediatric patients. An effort to improve the efficacy and tolerability of this antibiotic class has led to evaluation of extended-interval aminoglycoside administration (EIAA). EIAA is designed to achieve higher peak plasma aminoglycoside concentrations, with relatively undetectable trough concentrations, when compared with conventional aminoglycoside administration (CAA), and is therefore expected to be markedly effective and to reduce drug accumulation and prevent nephrotoxicity and ototoxicity. Clinical trials evaluating EIAA in neonates included patients with suspected Gram-negative infections requiring short courses of aminoglycoside therapy. Consequently, comparative efficacy of EIAA versus CAA could not be assessed. In addition, ototoxicity was often not assessed, and nephrotoxicity was virtually undetectable. Similarly, trials evaluating EIAA versus CAA in infants and children have not demonstrated a difference in outcomes. The use of EIAA in children with febrile neutropenia has been evaluated primarily with amikacin. The incidences of nephrotoxicity and ototoxicity were low, and were similar between EIAA and CAA. No deaths were reported in any of these studies; however, this could be related to the inclusion of patients with undocumented bacteremia. Further investigation of EIAA is necessary in patients with documented bacteremia, since plasma aminoglycoside concentrations were undetectable for most of the dosage interval in children with febrile neutropenia who were treated once daily. Overall, clinical studies suggest that EIAA has similar efficacy to, and no higher risk of toxicity than, CAA in neonates, infants, and children. A few evaluations have also demonstrated that EIAA is cost-effective in neonates and in children with febrile neutropenia. Future studies evaluating the efficacy and tolerability of EIAA in pediatric patients with documented systemic infections should be prospective, randomized, controlled trials with sample sizes sufficient to detect differences between administration methods. Further evaluations should also address the optimal dosage and cost-effectiveness of EIAA in infants and children.

A benefit-risk assessment of extended-release oxybutynin

Oxybutynin is a muscarinic receptor antagonist, which has been available for a number of years in its original immediate-release (IR) formulation. While oxybutynin IR has proven effective for the treatment of overactive bladder, its extended use can be limited by adverse effects, particularly dry mouth. An extended-release (ER) formulation of oxybutynin based on the OROS system has recently become available, which allows once daily administration. In direct comparison to oxybutynin IR, oxybutynin ER has an increased oral bioavailability for the parent compound oxybutynin which is accompanied by a reduced bioavailability for the active metabolite N-desethyl-oxybutynin. The latter has been implicated in mediating a major part of the adverse effects of oxybutynin treatment. Two double-blind, placebo-controlled, randomised studies in patients with overactive bladder have demonstrated that oxybutynin ER has a similar efficacy as oxybutynin IR but with improved tolerability. This is in line with clinical pharmacological studies demonstrating a smaller impairment of saliva production with oxybutynin ER than with oxybutynin IR. Thus, the ER formulation of oxybutynin maintains the therapeutic benefits and concomitantly improves tolerability.

Mechanism of late in-stent restenosis after implantation of a paclitaxel derivate-eluting polymer stent system in humans

BACKGROUND

We recently reported delayed angiographic restenosis in 15 patients who received 7-hexanoyltaxol (QP2)-eluting polymer stents (QuaDS) for the treatment of in-stent restenosis. This study presents the histological findings of atherectomy specimens from a subset of these patients receiving implants.

METHODS AND RESULTS

Between October and December 2001, 5 patients treated with QuaDS-QP2 stents underwent directional coronary atherectomy at 11.2+/-1.0 months for recurrent in-stent restenosis. Restenotic lesion composition was assessed with special stains, immunohistochemistry with quantitative image analysis, and, in one specimen, transmission electron microscopy. Atherectomy specimens contained fibrin interspersed in a smooth muscle cell-rich neointima with proteoglycan matrix. In 2 of 5 specimens, large aggregates of macrophages and T-lymphocytes were noted. These areas of active inflammation demonstrated a relatively high proliferation index by Ki-67 antibody staining, whereas the proliferation index in smooth muscle cell-rich restenotic areas was low.

CONCLUSION

Restenotic lesions from QuaDS-QP2-eluting stents at 12 months show persistent fibrin deposition with varying degrees of inflammation. These pathological changes, representing delayed healing, are usually observed up to only 3 months in human coronary arteries with stainless steel balloon-expandable stents. The nonreabsorbable polymer alone may have induced chronic inflammation.

Prevention of experimental cerebral vasospasm by intracranial delivery of a nitric oxide donor from a controlled-release polymer: toxicity and efficacy studies in rabbits and rats

BACKGROUND AND PURPOSE

A reduction in the local availability of nitric oxide (NO) may play a role in the etiology of chronic cerebral vasospasm after subarachnoid hemorrhage (SAH). We investigated the toxicity and efficacy of a locally delivered NO donor from a controlled-release polymer in preventing experimental cerebral vasospasm in rats and rabbits, respectively.

METHODS

Diethylenetriamine/NO (DETA/NO) was incorporated into controlled release ethylene-vinyl acetate (EVAc) polymers. Twenty-eight rats were used in a dose-escalation toxicity study to establish a maximally tolerated dose of DETA/NO-EVAc polymer. In the efficacy experiment, 20 rabbits were assigned to 4 experimental groups (n=5 per group): sham operation; SAH only; SAH+empty EVAc polymer; and SAH+DETA/NO-EVAc polymer. Treatment was initiated 30 minutes after blood deposition. Basilar artery lumen patency was assessed 72 hours after hemorrhage to evaluate the efficacy of DETA/NO in preventing cerebral vasospasm.

RESULTS

In the toxicity study, a dose of 3.4 mg/kg was identified as the LD(20) (dose with 20% mortality during the study period) of this DETA/NO formulation. Brain histology revealed hemorrhage and ischemic changes at the implantation site associated with high concentrations of DETA/NO. In the efficacy study, treatment with DETA/NO-EVAc polymer resulted in a significant decrease in basilar artery vasospasm compared with no treatment (93.0+/-4.9% versus 71.4+/-11.9%; P=0.035) or compared with treatment with blank EVAc polymer (93.0+/-4.9% versus 73.2+/-6.4%; P=0.003).

CONCLUSIONS

Local delivery of DETA/NO prevents vasospasm in the rabbit basilar artery. Local delivery of DETA/NO via polymers is a safe and effective strategy for preventing cerebral vasospasm after SAH in this model.

A six-month, open-label study assessing a new formulation of leuprolide 7.5 mg for suppression of testosterone in patients with prostate cancer

OBJECTIVE

The safety, efficacy, and pharmacokinetics of monthly subcutaneous injections of a new leuprolide acetate (LA) depot formulation were investigated in patients with advanced prostate cancer.

METHODS

The 2-part, 6-month (168-day), open-label, multicenter study enrolled male patients diagnosed with adenocarcinoma of the prostate (Jewett stage C or D). LA-2500 7.5-mg (a new subcutaneous depot formulation containing 7.5 mg of LA) injections were administered at monthly (28-day) intervals. The primary efficacy parameter was total serum testosterone level. A breakthrough response was defined as a single testosterone measurement > 50 ng/dL after achieving castration testosterone levels. Testosterone was isolated from sera by alumina column chromatography and measured by radioimmunoassay (RIA). LA was purified by solid-phase extraction and high-performance liquid chromatography and was then quantitated by RIA.

RESULTS

One hundred seventeen of the 120 enrolled patients completed the 6-month study. Three patients withdrew for reasons not related to treatment. LA had a mean (SD) maximal concentration of 26.3 (12.6) ng/mL at 4.66 (1.44) hours and was detected for a mean of 37 days (range, 28-49 days). By day 28, 94.1% (112/119) of the patients achieved medical castration (serum testosterone < or = 50 ng/dL). By day 42, 100.0% (118/118) of the patients remaining in the study had serum testosterone levels < or = 50 ng/dL and 97.5% (115/118) had levels < or = 20 ng/dL. At study completion, the mean (SD) serum testosterone level was 6.12 (4.3) ng/dL (range, 3.0-27.0 ng/dL). No breakthrough or acute-on-chronic responses were reported throughout the study. From baseline to month 6, mean (SD) luteinizing hormone level decreased from 8.0 (7.3) mIU/mL to 0.09(0.1) mIU/mL, and mean (SD) prostate-specific antigen level decreased from 32.9 (86.3) ng/mL to 3.2 (12.0) ng/mL. Treatment-related adverse events were reported by 74.2% (89/120) of patients, the most common being hot flashes (56.7%).

CONCLUSION

This 6-month, open-label, noncontrolled study showed LA-2500 7.5-mg depot was well tolerated and maintained testosterone suppression (< or = 50 ng/dL) in the patients completing the study without any testosterone breakthrough responses.

The newer antimuscarinic drugs: bladder control with less dry mouth

Two newer antimuscarinic anticholinergic drugs--tolterodine and extended-release oxybutynin--are approximately as effective in treating overactive bladder as immediate-release oxybutynin, but are more tolerable. I review clinical trial data on the newer agents.

Local chemotherapy with cisplatin-depot for glioblastoma multiforme

Glioblastoma multiforme (GBM) makes up as many as 30% of all primary brain tumors. Despite the employment of multimodal antitumor treatment, the overall survival is less than one year. Between 06/01/1998 and 06/01/2000 17 patients (Group A) with GBM (11 males, 6 females; median age 54.3 years) were administered local chemotherapy with cisplatin incorporated into biodegradable 6-carboxylcellulose polymer (cisplatin-depot (CDDP-D)). After the subtotal removal of GBM, twenty 1.5 x 1.5 cm polymer plates with a total area of 45 cm2 (the density of cisplatin immobilization on 6-carboxylcellulose being 1 mg/cm2, a total cisplatin dose of 45 mg) were implanted into the tumor bed. Group B (21 patients with GBM; 11 males, 10 females; median age 53.2 years) was control: the subtotal tumor ablation without CDDP-D implantation. Two to three weeks after the surgery all the patients of Groups A and B started a course of radiation therapy. A total dose of cranial irradiation was 20 Gy (1 fraction/day, 5 days/week; a daily dose of 2 Gy) followed by a boost tumor bed irradiation (1 fraction/day, 5 days/week; a daily dose of 2 Gy) up to the conventional dose of 60 Gy. Survival data for the patients were processed using the Kaplan-Meier method and analyzed by logrank test. All the patients of Group A tolerated surgical ablation of the brain tumor without side effects (brain edema, seizures, etc.). No patient of Group A had a reduction in blood cell counts during six weeks that would indicate systemic exposure to cisplatin. Blood chemistry and urinalysis did not show evidence of renal injury. No side effects of radiotherapy were registered in Group B either, regarding both the psychoneurological status of the patients and the basic values of homeostasis. Karnofsky performance scale (KPS) score of Group A and Group B patients demonstrated no significant differences before and after the surgery. The median overall survivals for patients of Group A and Group B were 427.5 and 211.0 days respectively (p = 0.00001; overall logrank test). Conclusion. Local chemotherapy of GBM with CDDP-D followed by irradiation is well tolerated and effective.

Long-Term Use of Contraceptive Depot Medroxyprogesterone Acetate in Young Women Impairs Arterial Endothelial Function Assessed by Cardiovascular Magnetic Resonance

Background— Depot medroxyprogesterone acetate (DMPA) inhibits proliferation of ovarian follicles, resulting in anovulation and a decrease in circulating estrogen; the latter action is potentially disadvantageous to cardiovascular health. We therefore investigated the vascular effects of long-term contraceptive DMPA in young women.

Methods and Results— Endothelium-dependent (hyperemia-induced flow-mediated dilatation [FMD]) and -independent (glyceryl trinitrate [GTN]) changes in brachial artery area were measured using cardiovascular magnetic resonance in 13 amenorrheic DMPA users (>1 year use; mean age 29±4 years) and in 10 controls (mean age 30±4 years, P =0.25) with regular menstrual cycles after validation of the technique. FMD and GTN responses were measured just before repeat MPA injection and 48 hours later (n=12) in DMPA users and during menstruation and midcycle (n=9) in controls. Serum-estradiol levels (S-estradiol) were measured at both visits. FMD was reduced in DMPA users compared with controls during menstruation (1.1% versus 8.0%, respectively P <0.01) without differences in GTN responses. S-estradiol levels in DMPA users were significantly lower than in controls during menstruation (58 versus 96 pmol/L, P <0.01). High levels of circulating MPA 48 hours after injection were not linked to an additional impairment in FMD (2.0% versus 3.1%, P =0.23). Estradiol levels were significantly correlated to FMD ( r =0.43, P <0.01).

Conclusions— Endothelium-dependent arterial function measured by cardiovascular magnetic resonance is impaired in chronic users of DMPA, and hypoestrogenism may be the mechanism of action. DMPA might adversely affect cardiovascular health, and in particular its use in women with cardiovascular disease should be additionally evaluated.

Hormones and weight change

Dysregulation of body weight has been a common complaint of women on hormonal contraception but an inconsistent event in controlled clinical studies. In a prospective trial to evaluate the relationship between depot medroxyprogesterone acetate (DMPA) and change in energy intake, energy expenditure and weight change, no effect from DMPA could be documented. These results refute a causal relationship between use of DPMA and increased weight. While weight gain and use of contraception may be common concomitant events in a population with a substantial propensity for weight fluctuation, the objective data suggest that factors other than contraceptive method are important. The controlled data have major implications for appropriate management and counseling of women seeking a highly effective method of protection against pregnancy.

Bone mineral density and DMPA

The relationship between depot medroxyprogesterone acetate (DMPA) and changes in bone mineral density remains controversial despite a substantial number of studies evaluating this potential association and its clinical relevance. While the majority of prospective studies suggest that DMPA produces a modest decline in bone density, several have failed to confirm this association, and none have documented any clinical consequences. The most recent data indicate that if bone density loss does occur in the presence of DMPA, it is reversible and unlikely to adversely influence clinical events either acutely or at a later time, such as in the postmenopausal period. In a risk:benefit evaluation, it is appropriate to consider any relationship between DMPA and changes in bone mineral density in the context of its established efficacy in pregnancy prevention.

Safety and efficacy of controlled-release oxycodone: a systematic literature review

Prescriptions for controlled-release oxycodone, a narcotic analgesic, recently contributed to a dramatic increase in pharmacy costs for a large private insurance company. To determine whether this agent offered clinical benefits over other available drugs that would justify its significantly greater cost, a systematic review of 16 clinical trials was undertaken. The review suggested that immediate-release and controlled-release preparations of oxycodone have similar efficacy and comparable side effect profiles. Controlled-release oxycodone has the advantage of less frequent dosing than immediate-release oxycodone; however, other agents may be dosed infrequently at much lower costs. For patients requiring a controlled-release opioid treatment, controlled-release morphine and methadone should be considered because they appear to be as effective as oxycodone and cost considerably less. Controlled-release oxycodone may be appropriate for some patients, particularly if they cannot tolerate other controlled-release or long-acting opioid analgesics.

Efficacy, safety, and tolerability of extended-release once-daily tolterodine treatment for overactive bladder in older versus younger patients

OBJECTIVES

To evaluate the efficacy, safety, and tolerability of a new, once-daily extended-release (ER) formulation of tolterodine in treating overactive bladder in older (> or =65) and younger (<65) patients.

DESIGN

A 12-week double-blind, placebo-controlled clinical trial.

SETTING

An international study conducted at 167 medical centers.

PARTICIPANTS

One thousand fifteen patients (43.1% aged > or =65) with urge incontinence and urinary frequency.

INTERVENTION

Patients were randomized to treatment with tolterodine ER 4 mg once daily (qd) (n = 507) or placebo (n = 508) for 12 weeks.

MEASUREMENTS

Efficacy, measured with micturition charts (incontinence episodes, micturitions, volume voided per micturition) and subjective patient assessments, safety, and tolerability endpoints were evaluated, relative to placebo, according to two age cohorts: younger than 65 and 65 and older.

RESULTS

Mean age in the older and younger patient cohorts was 74 (range 65-93) and 51 (range 20-64), respectively. Compared with placebo, significant improvements in micturition chart variables with tolterodine ER showed no age-related differences. Irrespective of age, significantly more tolterodine ER recipients than placebo recipients reported an improvement in urgency symptoms. After 12 weeks of treatment with tolterodine ER, a fivefold increase in the percentage of patients able to finish tasks before voiding in response to urgency was noted in both age groups (<65: from 6.5-32.8%, > or =65: from 5.1-26.2%). Tolterodine ER recipients, irrespective of age, also had significant improvements in their bladder condition than did placebo recipients. Overall, a greater percentage of patients, irrespective of age, perceived any benefit with tolterodine ER than with placebo (P <.001). Dry mouth (of any severity) was the most common adverse event in both the tolterodine ER and placebo treatment arms, irrespective of age (<65: ER 22.7%, placebo 8.1%; > or =65: ER 24.3%, placebo 7.2%). Few patients (<2%) experienced severe dry mouth. No central nervous system, visual, cardiac (per electrocardiogram), or laboratory safety concerns were noted. Withdrawal rates due to adverse events on tolterodine ER 4 mg qd were comparable in the two age cohorts (<65: 5.5%; > or =65: 5.1%; P =.87).

CONCLUSIONS

The new, once-daily ER formulation of tolterodine is efficacious, safe, and well tolerated in the treatment of patients with symptoms of overactive bladder, irrespective of age.

Tolerability of beta-blocker initiation and titration in the Metoprolol CR/XL Randomized Intervention Trial in Congestive Heart Failure (MERIT-HF)

BACKGROUND

beta-Blockade improves survival when administered over a long period of time to patients with heart failure. However, the time course of any possible deterioration during the titration phase has not been reported.

METHODS AND RESULTS

We looked at evidence of clinical deterioration in the Metoprolol CR/XL Randomized Intervention Trial in Congestive Heart Failure (MERIT-HF) by analyzing events and symptoms during the first 90 days. During titration, the Kaplan-Meier curves for the combined end point of all-cause mortality/all-cause hospitalization were similar in all patients randomized, with no significant difference in favor of placebo at any visit or in any of the analyzed subgroups (New York Heart Association class II, III/IV, or III/IV with ejection fraction <0.25, heart rate less-than-or-equal 76 bpm, and systolic blood pressure less-than-or-equal 120 mm Hg). The curves started to diverge in favor of beta-blockade after 60 days. Low heart rate was the main factor that limited titration. In New York Heart Association class III/IV, 5.9% of the patients receiving placebo discontinued study medicine during the first 90 days compared with 8.1% of those receiving metoprolol CR/XL (P=0.037 unadjusted, P=NS adjusted); corresponding figures in those with New York Heart Association class III/IV and ejection fraction <0.25 were 7.1% and 8.0% (P=NS). From day 90 until the end of the study, more patients in the placebo group discontinued study medicine in all subgroups. There was no change in diuretic or ACE inhibitor dosing with beta-blocker titration. Most patients reported no change in symptoms of breathlessness or fatigue during the titration phase.

CONCLUSIONS

When carefully titrated, metoprolol CR/XL can be given safely to the overwhelming majority of patients with stable mild to moderate heart failure, with minimal side effects or deterioration.

Comparison of the bioavailability of unequal doses of divalproex sodium extended-release formulation relative to the delayed-release formulation in healthy volunteers

Valproate formulations, divalproex sodium extended-release (ER) and the traditional divalproex sodium delayed-release (DR) formulations, are not bioequivalent. This study evaluated if ER QD regimens with 14 and 20% higher daily doses were equivalent to the corresponding DR BID regimens with respect to exposure (AUC) while achieving lower maximum concentration (C(max)) and higher minimum concentration (C(min)) values. This was a Phase I, multiple-dose, fasting, randomized, open-label, crossover design study in healthy adult volunteers (n=36). The two crossover comparisons of unequal total daily doses were: 1000 mg ER versus 875 mg DR and 1500 mg ER versus 1250 mg DR. For each of 14 and 20% higher ER versus DR dose comparisons, the ER and DR regimens were equivalent with respect to AUC. Furthermore, the ER formulation achieved a lower C(max) central value and a higher C(min) mean than the corresponding values for the DR formulation. The mean peak-to-trough fluctuations of valproic acid plasma concentrations were 42-48% lower for the ER formulation compared with the DR. The higher ER doses were as well tolerated as DR, with a small number of adverse events that were non-serious in nature and mild in intensity. Therefore, increasing the once-daily ER dose 14-20% while converting from a total daily DR dose given twice-daily results in equivalent exposure with lower C(max) and higher C(min) values.

A double-blind, parallel-group study of amlodipine versus long-acting nitrate in the management of elderly patients with stable angina

Ninety-seven elderly patients with stable angina were included in a 28-week, randomized, double-blind, parallel-group comparison of amlodipine 5-10 mg and isosorbide mononitrate 25-50 mg once daily. The total exercise time, as limited by angina, was recorded together with the median incidence per week of angina attacks and glyceryl trinitrate consumption. Safety was assessed by adverse event frequency, measurement of vital signs and laboratory parameters, and quality of life. At the final visit, the total exercise time was significantly greater relative to baseline with amlodipine than isosorbide mononitrate (final/baseline difference: 112.2 vs. 32.2, p = 0.016). There were no statistically significant differences between the groups in relation to the incidence of adverse events. Once daily amlodipine provides significantly better control of stable angina than isosorbide mononitrate in this elderly population.

Depot naltrexone: long-lasting antagonism of the effects of heroin in humans

RATIONALE

Naltrexone, an opioid antagonist, is currently approved as a treatment for heroin dependence. However, naltrexone is generally not well accepted by patients, and medication non-compliance is a difficult obstacle to treatment. A sustained-release form of naltrexone may improve compliance.

OBJECTIVE

The present study was designed to evaluate the time course, safety, and effectiveness of a depot formulation of naltrexone (Depotrex).

METHODS

Twelve heroin-dependent individuals participated in an 8-week inpatient study. After a 1-week detoxification period, six participants received 192 mg naltrexone base and six participants received 384 mg naltrexone base. For safety, the low dose of depot naltrexone was tested before the high dose. The effects of heroin (0, 6.25, 12.5, 18.75, 25 mg, i.v.) were evaluated for the next 6 weeks. One dose of heroin was tested per day on Mondays through Fridays, and the entire dose range was tested each week. Active heroin doses were administered in ascending order during the week, while placebo could be administered on any day. Subjective, performance, and physiological effects were measured both before and after heroin administration. The hypotheses were that depot naltrexone would antagonize the effects of heroin, and that the high dose of depot naltrexone would produce a more effective and longer-lasting antagonism than the low dose.

RESULTS

The low and high doses of depot naltrexone antagonized heroin-induced subjective ratings for 3 and 5 weeks, respectively. Plasma levels of naltrexone remained above 1 ng/ml for approximately 3 and 4 weeks after administration of 192 mg and 384 mg naltrexone. Other than the initial discomfort associated with the injection of depot naltrexone, there were no untoward side-effects.

CONCLUSIONS

These results suggest that this depot formulation of naltrexone provides a safe, effective, long-lasting antagonism of the effects of heroin.

Complications of ultrarapid opioid detoxification with subcutaneous naltrexone pellets

Rapid and ultrarapid opioid detoxification (ROD and UROD) centers promise quick, painless, same-day detoxification treatment for patients with opioid addiction. The goal of ROD and UROD is to provide a rapid transition from opioid dependency to oral naltrexone therapy. The patient is given general anesthesia and high-dose opioid antagonists. This induces a severe withdrawal but spares the patient the experience. In theory, the process is complete within four to five hours. The patient awakens without opioid dependency and is started on oral naltrexone. Any subsequent, persistent withdrawal symptoms are treated symptomatically. A novel, unapproved approach is to compound a pellet of naltrexone and implant it in the subcutaneous tissue. In theory, this should result in continuous therapeutic levels for this drug, and avoid issues with noncompliance.

CASE SERIES

This article reports six cases of complications from the same detoxification center that performed UROD with naltrexone pellet implantation, including pulmonary edema, prolonged withdrawal, drug toxicity, withdrawal from cross-addiction to alcohol and benzodiazepines, variceal rupture, aspiration pneumonia, and death.

CONCLUSIONS

The risks of this procedure are great and further studies should assess its safety and the novel use of naltrexone.

Pharmacokinetics, tolerability, and fructosamine-lowering effect of a novel, controlled-release formulation of alpha-lipoic acid

OBJECTIVE

To determine the pharmacokinetics, safety, and tolerability of a novel, controlled-release oral formulation of alpha-lipoic acid (LA) and to investigate whether sustaining the concentration of LA in plasma would have a beneficial effect on glycemic control in patients with type 2 diabetes.

METHODS

For the pharmacokinetic study, a single, 600-mg dose of either controlled-release LA (CRLA) or quick-release LA (QRLA) was administered orally to 12 normal human subjects. The plasma profile of LA was determined for 24 hours after administration of the dose,and pharmacokinetic analyses were performed. For the safety and tolerability study, 21 patients with type 2 diabetes were given 900 mg of CRLA daily for 6 weeks, followed by 1,200 mg of CRLA daily for an additional 6 weeks. Active treatment was followed by a 3-week washout period. Throughout the study, patients continued to take their prestudy antidiabetic medications, which included metformin (Glucophage), sulfonylureas (Amaryl, glyburide, and Glucotrol), acarbose (Precose), troglitazone (Rezulin), and insulin (either as monotherapy or in combination). CRLA was evaluated for safety and tolerability as well as for effects on glycemic control.

RESULTS

The Tmax (time to maximal plasma concentration) of LA administered as CRLA was 1.25 hours and was approximately 2.5-fold longer in comparison with the Tmax for QRLA (Tn,5X = 0.5 hour; P<0.02). No severe side effects or changes in either liver or kidney function or hematologic profiles were noted after the administration of CRLA. In 15 patients, the mean plasma fructosamine concentration was reduced from 313 to 283 micromol/L(P<0.05) after 12 weeks of treatment with CRLA.

CONCLUSION

CRLA increased the plasma concentration of LA over time in healthy subjects, and CRLA was safe, well tolerated, and effective in reducing plasma fructosamine in patients with type 2 diabetes.

Gastrointestinal safety of an extended-release, nondeformable, oral dosage form (OROS: a retrospective study

BACKGROUND

The OROS osmotic (OSM) dosage form optimises extended-release oral administration by controlling the rate of drug release for a predetermined time, providing constant, patterned, or pulsed delivery profiles. OSM products include prescription medications for urology, CNS, and cardiovascular indications, as well as over-the-counter nasal/sinus congestion medications.

METHODS

This retrospective study examines US gastrointestinal (GI) safety data for the OROS dosage form following nearly two decades of use. Although GI injury and obstruction are known effects of oral medications, some reports have suggested that extended-release products pose a greater risk of GI injury and obstruction than other oral dosage forms. Products incorporating OROS technology are being prescribed to an expanding range of patients; a review of the GI safety data for this dosage form thus seemed timely and appropriate. US safety information was obtained from three sources: English language literature published from 1982 until June 1, 2000 from five major biomedical databases;postmarketing safety reports from January 1, 1983 until June 1, 2000 available through the Freedom of Information Act; andcommercial safety information obtained directly from ALZA Corporation's in-house safety database for those OSM products for which ALZA has reporting responsibility. US distribution data from IMS National Prescription Audit trade mark Plus data were used to estimate cumulative product distribution totals. These totals were combined with numbers of unique GI events to determine the estimated frequency of events.

RESULTS

Nearly 13 billion OSM tablets are estimated to have been distributed in the US. The incidence of all clinically significant GI adverse events for OSM products (including intestinal, gastric, and oesophageal irritation, injury, and obstruction) reported in the US was approximately one case in >76 million tablets distributed. The majority (78%; estimated incidence: one case in 29 million tablets) of cases were reported in patients taking Procardia XL (nifedipine). Oesophageal and lower GI obstruction were reported primarily in patients with pre-existing abnormalities or disease of the GI tract. Among paediatric patients, one obstruction was reported in an estimated 37.7 million tablets distributed. Reports of GI irritation associated with OSM products were consistent with known effects of the same drug substances in other dosage forms.

CONCLUSION

A review of long-term safety experience with products using OSM controlled-release technology yields a low incidence of clinically significant GI events. Properly prescribed, extended-release products provide substantial therapeutic and convenience benefits without additional risk.

Treatment of overactive bladder with once-daily extended-release tolterodine or oxybutynin: the antimuscarinic clinical effectiveness trial (ACET)

Treatment with the antimuscarinic agents tolterodine and oxybutynin is the mainstay of therapy for overactive bladder, a chronic and debilitating condition characterized by urinary urgency with or without urge incontinence, usually in combination with urinary frequency and nocturia. This study consisted of two trials; in one, patients with overactive bladder were randomized to 8 weeks of open-label treatment with either 2 mg or 4 mg of once-daily extended-release tolterodine (TER), and in the other to 5 mg or 10 mg of extended-release oxybutynin (OER). The study protocol and design were identical for the two trials and site selection ensured that there was no bias in either trial for the tendency of investigators to prescribe one drug rather than the other, or for geographical location. A total of 1289 patients were enrolled, 669 in the tolterodine trial (TER 2 mg, n = 333; TER 4 mg, n = 336) and 620 in the oxybutynin trial (OER 5 mg, n = 313; OER 10 mg, n = 307). Fewer patients prematurely withdrew from the trial in the TER 4 mg group (12%) than either the OER 5 mg (19%; p = 0.01) or OER 10 mg groups (21%; p = 0.002). More patients in the OER 10 mg group than the TER 4 mg group withdrew because of poor tolerability (13% vs 6%; p = 0.001). After 8 weeks, 70% of patients in the TER 4 mg group perceived an improved bladder condition, compared with 60% in the TER 2 mg group, 59% in the OER 5 mg group and 60% in the OER 10 mg group (all p < 0.01 vs TER 4 mg). Response to therapy was greater in a subgroup of patients whose perception of bladder condition was moderate to severe at baseline (TER 4 mg 77% vs OER 10 mg 65%; p < 0.01). Dry mouth was dose-dependent with both agents, although differences between doses only reached statistical significance in the oxybutynin trial (OER 5 mg vs OER 10 mg; p = 0.05). Patients treated with TER 4 mg reported a significantly lower severity of dry mouth compared with OER 10 mg. In conclusion, the greater efficacy and tolerability of tolterodine ER 4 mg suggests improved clinical effectiveness compared with oxybutynin ER 10 mg.

Vaginal discharge: a perceived side effect and minor reason for discontinuation in hormonal injectable users in South Africa

Poor compliance and high discontinuation rates have been observed in users of injectable hormonal contraception in South Africa. The objective of this study was to assess the side effects and reasons for discontinuation in new users of both depot-medroxyprogesterone acetate (DMPA) and norethisterone oenanthate (NET-EN). One hundred and eighty nine women were recruited into a two-year follow-up study. At each visit for a repeat injection, users were asked about bleeding patterns and side effects. Vaginal discharge, often described as watery in consistency, was perceived to be a problem amongst women and their partners. In total, one fifth (20%) of women reported an increase in discharge during use of the method and three women cited this discharge to be the primary reason for discontinuation of the method. This side effect was mainly noted in the first few months of use. Health care providers believed that this was a side effect of both DMPA and NET-EN, and women who presented with this complaint were rarely investigated for presence of sexually transmitted diseases.

Venlafaxine and generalised anxiety disorder: new preparation. Minimise recourse to drugs

(1) Generalised anxiety disorder is defined as excessive anxiety for at least 6 months. (2) Management is based primarily on psychological measures, with the aim of limiting recourse to drugs. The reference drugs are benzodiazepines. The treatment period should be as short as possible, to avoid adverse effects such as sedation and dependence. (3) Venlafaxine is a non tricyclic, non MAOI antidepressant. A sustained-release formulation has just been granted marketing authorisation in France for generalised anxiety disorder. (4) The clinical assessment file on venlafaxine in this indication includes results from two 8-week trials and a placebo-controlled trial with 6 months follow-up. The trials showed a significant improvement with venlafaxine on standard anxiety scales, but the clinical impact (at best moderate) has been poorly assessed. We found no comparison between venlafaxine and benzodiazepines. (5) In one trial venlafaxine was no more effective than buspirone. (6) The most frequent adverse effects of venlafaxine are gastrointestinal disorders, insomnia and dizziness. Venlafaxine carries a risk of drug interactions and withdrawal symptoms. (7) In practice, venlafaxine provides nothing new in the treatment of generalised anxiety disorder. The reference drug treatment remains a benzodiazepine.

Dual-release formulation, a novel principle in L-dopa treatment of Parkinson's disease

A single morning dose of dual-release formulation was compared with a slow-release formulation of L-dopa plus benserazide in a randomized, double-blind, cross-over study in 16 fluctuating patients with PD. The mean time to "on" was shorter with the dual-release formulation (43 +/- 31 minutes) than with the slow-release formulation (81 +/- 39 minutes) (p < 0.001), whereas the mean time to relapse to "off" was similar for both formulations. The dual-release formulation had a significantly shorter time to reach peak concentration (t(max)) and greater maximum concentration (C(max)) and area under the plasma concentration time curve (AUC(0--5 h)) than the slow-release formulation, whereas apparent elimination half-life (t(1/2)) was similar for both formulations.

Influence of protein supplementation and implant status on alleviating fescue toxicosis

Heat stress is a major problem in transporting stocker calves with symptoms of fescue toxicosis. Removing calves from tall fescue pastures and offering diets devoid of endophyte-infected tall fescue could reduce the severity of toxicosis and precondition calves for transport to the feedlot. In the present experiment, a pasture phase was used to condition yearling steers to grazing tall fescue and induce symptoms of fescue toxicosis, and a pen phase followed to determine effects of implanting at the start of grazing and protein supplementation (hay only vs hay plus supplement) on short-term changes in rectal temperature and serum prolactin concentration. Neither implant status nor protein supplementation affected (P > 0.10) white blood cell count or rectal temperature. White blood cell counts at the conclusion of the pasture phase averaged 8,778 cells/microL and were within a range indicating no immunological response. Changes in rectal temperature and serum prolactin concentration during the pen phase were not influenced (P > 0.10) by implanting or supplementation. Initial rectal temperatures for the pen phase were high (39.9 degrees C) but declined linearly (P < 0.001) over the first 106 h and were below a normal temperature (39.2 degrees C) by 82 h following removal from tall fescue pastures. Serum prolactin gradually increased (P < 0.001) to a peak by 82 h and stabilized thereafter. Results indicate that neither supplemental protein nor an estrogenic implant influenced recovery indices of fescue toxicosis, whereas removing calves from tall fescue pastures and excluding dietary tall fescue for 3 to 4 d may alleviate symptoms of fescue toxicosis.

Iatrogenic esophagitis

A variety of medications have been reported to cause esophageal injury. Nearly 1000 cases have probably been described in the past 30 years, and this is a vast under-representation. Pill-induced esophageal injury is also associated with many underlying esophageal diseases. This review addresses the etiology, diagnosis, and clinical features of pill-induced esophageal injury as well as the specific medications that have been reported to cause it. Ways to prevent esophageal injury, including better instructions to patients who are prescribed such medications, are also discussed.

Poly(ethylene glycol) multiblock copolymer as a carrier of anti-cancer drug doxorubicin

The synthesis of a novel water-soluble polymer drug carrier system based on biodegradable poly(ethylene glycol) block copolymer is described in this paper. The copolymer consisting of PEG blocks of molecular weight 2000 linked by means of an oligopeptide with amino end groups was prepared by interfacial polycondensation of the diamine and PEG bis(succinimidyl carbonate). The structure of the oligopeptide diamine consisting of glutamic acid and lysine residues was designed as a substrate for cathepsin B, a lysosomal enzyme, which was assumed to be one of the enzymes responsible for the degradation of the polymer carrier in vivo. Each of the oligopeptide blocks incorporated in the carrier contained three carboxylic groups of which some were used for attachment of an anti-cancer drug, doxorubicin (Dox), via a tetrapeptide spacer Gly-Phe-Leu-Gly. This tetrapeptide spacer is susceptible to enzymatic hydrolysis. In vitro release of Dox and the degradation of the polymer chain by cathepsin B as well as preliminary evaluation of in vivo anti-cancer activity of the conjugate are also demonstrated.

The preventative role of antioxidants (selegiline and vitamin E) in a rat model of tardive dyskinesia

BACKGROUND

We examined the potential protective effects of two potent antioxidants, selegiline and vitamin E, in a rodent model of tardive dyskinesia (TD), viz. neuroleptic-induced spontaneous orofacial movements.

METHODS

Rats were treated with fortnightly injections of fluphenazine decanoate for 12 weeks, and examined at baseline and at fortnightly intervals for vacuous chewing movements, mouth tremors and tongue protrusions.

RESULTS

The administration of fluphenazine led to a progressive increase of all three types of orofacial movements. In the first study, the impact of the concomitant administration of selegiline on orofacial movements was examined. Selegiline led to a reduction in orofacial movements in neuroleptic-treated rats to the level of control rats not being administered a neuroleptic drug. In the second study, rats were fed diets either high or low in their vitamin E content. High and low vitamin E diets did not significantly affect neuroleptic-induced orofacial movements.

CONCLUSIONS

Our studies provide some support for the hypothesis that oxidative injury may play a role in the genesis of neuroleptic-induced movement disorder, and prompt further examination of this hypothesis in both animals and humans.

Cardiovascular effects of a single slow release lanreotide injection in patients with acromegaly and left ventricular hypertrophy

In our study we assessed the effects of a single i.m. injection of slow-release Lanreotide (30 mg) (SR-L), a new long-acting somatostain analog, on circulating GH levels, baseline cardiac function (M-mode, 2D guided, doppler-echocardiographic study) and cardiopulmonary response to exercise (cycloergometric test, performed using a computer drived, electrically braked cycle ergometer), tested at baseline, after 7 and 14 days from the injection in 10 acromegalic patients (5 M, 5 F, mean age 57.7 +/- 3.1 yrs, body mass index (BMI) 27 +/- 0.8 kg/m2, blood pressure 141 +/- 6.5/82 +/- 3 mmHg). SR-L administration decreased GH levels in acromegalic patients (mean +/- SEM) from 16.1 +/- 6.9 to 10.8 +/- 5.1 micrograms/L (p = 0.045) after 7 days and to 11.9 +/- 5 micrograms/L (p = 0.078) after 14 days from the injection. Moreover, we observed a significant (p < 0.05) decrease in systolic blood pressure and heart rate at the 7th (135 +/- 6.1 vs 141 +/- 6.5 mmHg, and 68 +/- 2.1 vs 74 +/- 2.1 bpm) and 14th (137 +/- 6.2 vs 141 +/- 6.5 mmHg, and 72 +/- 2 vs 74 +/- 2.1 bpm) day of the study with respect to the baseline values. After SR-L administration we also found an increase in ejection fraction (69 +/- 2 vs 63 +/- 2.3% at 7th day, p = 0.006; 65 +/- 2.3 vs 63 +/- 2.3% at the 14th day, p = 0.027) and shortening fraction (40.8 +/- 1.8 vs 36.6 +/- 1.9% at 7th day, p = 0.005; 38.7 +/- 1.8 vs 36.6 +/- 1.9% at the 14th day, p = 0.045). The positive acute cardiac response to SR-L injection was also demonstrated by the increase in A/E velocity ratios at 7th (1.14 +/- 0.1 vs 0.98 +/- 0.07, p = 0.016) and 14th (1.04 +/- 0.08 vs 0.98 +/- 0.07, p = 0.008) day of the study. After SR-L injection, exercise capacity and VO2 at anaerobic threshold were also increased with respect to the baseline test: 61.1 +/- 8.2 vs 38.9 +/- 6.8 watts (p = 0.002) and 1012.4 +/- 71.5 vs 915.3 +/- 77.8 mL/min (p = 0.033) after 7 days, and 61.4 +/- 7.2 vs 38.9 +/- 6.8 watts (p = 0.002) and 1010.1 +/- 62.5 vs 915.3 +/- 77.8 mL/min (p = 0.010) after 14 days from the injection. In conclusion, these results suggest that in acromegalic patients: (1) SR-L causes a rapid improvement in baseline cardiac function and in cardiopulmonary performance during exercise in acromegaly; (2) the endocrine (decrease in GH levels) and echocardiographic responses to SR-L are maximal after 7 days from the injection, whereas the effect of SR-L on the exercise performance are longer lasting.

Immediate-release and controlled-release carbidopa/levodopa in PD: a 5-year randomized multicenter study. Carbidopa/Levodopa Study Group

OBJECTIVE

To compare effects of immediate-release (IR) and sustained-release (CR) carbidopa/levodopa in levodopa-naive PD patients.

BACKGROUND

It was hypothesized that the long-acting preparation would be associated with fewer long-term complications.

METHODS

A total of 618 patients were studied in 36 centers worldwide in a blinded, randomized parallel study. Measures of efficacy and adverse reactions were recorded at 3-month intervals for 5 years. Motor fluctuations and dyskinesias were evaluated by a patient diary and a physician-recorded questionnaire. The Nottingham Health Profile (NHP) was used to evaluate quality of life.

RESULTS

Approximately 60% of patients completed the trial. After 5 years, the mean dose of IR was 426 mg/day, and the bioavailable dose of CR was 510 mg/day (mean dose, 736 mg/day). After 5 years, 20.6% of the IR group and 21.8% of the CR group had motor fluctuations or dyskinesia. Sixteen percent of both groups had changes in motor response by the questionnaire's definition. There was no significant difference between the two treatment groups. Disability scores and the motor score of the Unified Parkinson Disease Rating Scale (UPDRS) were highest at baseline, improved with therapy, and thereafter worsened over time to reach baseline scoring at the end of 5 years. The CR group was superior to IR for the Activities of Daily Living subsection of the UPDRS for all 5 years and for emotional reactivity and social isolation on the NHP; however, this may have resulted from higher doses of CR that were used.

CONCLUSION

Despite the progressive nature of PD, both the immediate-release and sustained-release carbidopa/levodopa formulations maintained a similar level of control in PD after 5 years compared with baseline. Additionally, the low incidence of motor fluctuations or dyskinesia was not significantly different between the treatment groups and may be partly attributed to the relatively low doses of levodopa used throughout the 5-year study.

Use of partial liquid ventilation to manage pulmonary complications of acute verapamil-sustained release poisoning

INTRODUCTION

Verapamil is a papaverine-derived calcium channel blocker widely used for the treatment of hypertension and supraventricular tachyarrhythmias. It is one of the leading agents involved in pharmaceutical poisoning-related deaths among adults.

CASE REPORT

We report a case of severe sustained-release verapamil poisoning associated with respiratory failure in an adult man who survived after receiving 4 days of partial liquid ventilation as a part of his medical management.

The treatment of negative symptoms: a clinical and methodological study

The primary objective of this study was to evaluate the efficacy, safety and tolerability of remoxipride (controlled release) versus haloperidol in patients with negative symptoms. The study comprised a multicentre, randomised, double-blind, parallel-group clinical trial. Two hundred and five patients were randomised to either remoxipride or haloperidol. Patients eligible for this study were aged 18-65 years, met the DSM-III-R diagnosis for chronic schizophrenia and the Positive and Negative Symptoms Scale (PANSS) criteria for predominant negative symptoms. There was a statistically significant reduction in the PANSS scores of at least 20% from baseline to last rating for 39 remoxipride (49.4%) and 45 haloperidol (47.6%) treated patients. There were no statistical differences found between the two treatment groups with respect to improvement of negative symptoms and adverse events. The PANSS data suggest that both remoxipride and haloperidol improve the cluster of negative symptoms concerned with social functioning. In addition, the design of the study provides a methodology that is appropriate to the study of primary negative symptoms in schizophrenia.

Isosorbide 5-mononitrate: a review of a sustained-release formulation (Imdur) in stable angina pectoris

Imdur (IMD) is a sustained-release isosorbide 5-mononitrate preparation for the treatment of chronic stable angina pectoris. Controlled medication release is achieved using the Durules principle of insoluble matrix embedding. Data from randomised double-blind trials show that IMD 60 mg once daily (the most widely studied dosage) has significant antianginal and anti-ischaemic effects compared with placebo after 2 weeks' treatment. Efficacy was generally observed approximately 1 to 12 hours after administration, indicating that once-daily administration in the morning will provide effective prophylaxis of symptoms throughout the day. Improvements from baseline are generally maintained during IMD repeated treatment. There was no evidence of classical tolerance to IMD 30 to 240 mg/day in a large well designed study. Although improvements from baseline were maintained over 6 weeks with IMD 30 or 60 mg/day, statistical significance versus placebo was eventually lost because of improved performance in the placebo group. IMD 120 or 240 mg/day were more effective than placebo after 6 weeks. Studies lasting up to 2 weeks found no evidence of tolerance to IMD 60 mg/day. In comparative trials lasting approximately 2 weeks, IMD 60 mg once daily was more effective than isosorbide dinitrate 30 mg 4 times daily and similar to or better than isosorbide dinitrate 20 mg 3 times daily. Preliminary data show that IMD 60 mg once daily has similar efficacy to diltiazem 60 mg 3 times daily and is at least as effective as certain other sustained-release isosorbide 5-mononitrate preparations. There is no evidence for rebound worsening of ischaemia 24 hours after IMD administration. Abrupt discontinuation during long term IMD treatment may exacerbate anginal symptoms. In general, IMD is well tolerated. The most frequently reported adverse event, headache, is usually mild to moderate, improves with long term therapy and rarely leads to treatment withdrawal. Patient compliance is better with once-daily administration of IMD than with twice-daily administration of conventional isosorbide 5-mononitrate.

CONCLUSIONS

In patients with chronic stable angina, IMD provides effective antianginal prophylaxis for up to 12 hours and does not seem to be associated with rebound phenomena at the end of the dosage interval. Improvements from baseline are maintained during repeated administration, although loss of statistically significant superiority over placebo was evident during 6 weeks' treatment with IMD < or =60 mg/day in 1 study. Further evaluation of comparative efficacy (particularly with respect to other sustained-release preparations) and long term effects would be beneficial. Nevertheless, the available data suggest that IMD is a useful and convenient agent for the treatment of patients with chronic stable angina pectoris.

Accidental ingestion of sustained release calcium channel blockers in children

We examined the effects of small ingestions of sustained release calcium channel blockers (SR-CCBs) in young children and characterized current recommendations regarding monitoring after a suspected ingestion. A 2-part study was performed of pediatric calcium channel blocker (CCB) ingestion: first a telephone survey of 33 randomly selected Poison Control Centers (PCCs) from around the US concerning their recommended management of a small ingestion of sustained release calcium channel blocker in a child, and then a 5-y retrospective review of local cases of CCB ingestions in children under 4 y-of-age. The number of hours of medical observation recommended by the PCCs varied from > or = 24 h (n = 15, 45%) to < 6 h (n = 6, 18%). The retrospective chart review revealed that 19 of 29 local cases involved a SR-CCB, and 6 of these were thought to have ingested only 1 tablet. Observation time varied from > 24 h to < 6 h in the 17 cases seen in an emergency department. No symptoms or vital sign abnormalities were reported in any case. Recommendations regarding duration of observation varied from < 6 h to 24 h. Ingestion of a few SR-CCB tablets was not associated with symptoms, suggesting that admission and 24-h monitoring may not be necessary under those circumstances.

A survey of the attitudes of chronic psychiatric patients living in the community toward their medication

Because non-compliance with antipsychotic drug therapy is both common and associated with a substantially increased risk of acute relapse, depot medication must be preferred for most schizophrenic out-patients. Yet there is a perception that depot medication is unpopular among patients. In the survey of out-patients reported here, the great majority of patients receiving either oral or depot neuroleptics (with or without oral augmentation) would, given a free choice, elect to continue with their present dose form (94% and 87%, respectively). In virtually all cases, the choice of route was made by the treating physician and readily accepted by the patient. These findings suggest that physicians should more often recommend and prescribe depot medication when antipsychotic maintenance therapy is indicated.