Roflumilast: a phosphodiesterase-4 inhibitor for the treatment of respiratory disease

Asthma and chronic obstructive pulmonary disease (COPD) are two of the most common chronic diseases worldwide, yet the classes of drug licensed to treat these conditions have not changed appreciably over the last 20 years. Inhaled bronchodilators and glucocorticosteroids (often in combination) form the mainstay of therapy for respiratory diseases, but many patients (including the elderly and children) can have problems using inhaler devices and there is a clear preference for oral therapy. The prevalence of these respiratory diseases is on the increase worldwide and continues to represent an area of medicine with unmet medical needs, particularly in the treatment of COPD. Despite this increase, very few new classes of drugs have been introduced into clinical practice. Phosphodiesterase-4 inhibitors are a novel class of drugs in development for the treatment of respiratory diseases and there are a number of lead compounds in late clinical development. This review focuses on one of the most promising drugs in development, roflumilast, which has undergone extensive clinical evaluation.

PDE4 inhibitors as potential therapeutic agents in the treatment of COPD-focus on roflumilast

Chronic obstructive pulmonary disease is characterized by a rapid decline in lung function due to small airway fibrosis, mucus hypersecretion and emphysema. The major causative factor for COPD is cigarette smoking that drives an inflammatory process that gives rise to leukocyte recruitment, imbalance in protease levels and consequently matrix remodeling resulting in small airway fibrosis and loss of alveolar tissue. Current drug treatment improves symptoms but do not alter the underlying progression of this disease. The failure of antiinflammatory drugs like glucocorticosteroids to have a major impact in this disease has hastened the need to develop novel therapeutic strategies. Phosphodiesterase (PDE) 4 inhibitors are novel anti-inflammatory drugs that have recently been show to document clinical efficacy in this disease, although their utility is hampered by class related side-effects of nausea, emesis and diarrhea. Whilst it is not yet clear whether such drugs will prevent emphysema, this is a distinct possibility provided experimental observations from preclinical studies translate to man. This review will discuss the current standing of PDE4 inhibitors like roflumilast as novel treatments for COPD and the potential for developing nonemetic anti-inflammatory drugs.

[Applications and safety of modern antidepressants in patients with liver diseases]

In the study we subjected to analysis literature referred to safety of SSRI's, venlafaxine, milnacipran, mirtazapine, nefazodone and trazodone in patients with the diagnosis of depression and concomitant hepatopathy.

Anticonvulsant activity, neural tube defect induction, mutagenicity and pharmacokinetics of a new potent antiepileptic drug, N-methoxy-2,2,3,3-tetramethylcyclopropane carboxamide

N-methoxy-2,2,3,3-tetramethylcyclopropane carboxamide (OM-TMCD) is a methoxyamide derivative of a cyclopropyl analogue of valproic acid (VPA). The structural considerations used in the design of OM-TMCD were aimed to enhance OM-TMCD anticonvulsant potency (compared to VPA) and to prevent VPA's two life-threatening side effects, i.e., induction of neural tube defects (NTDs) and hepatotoxicity. Following i.p. administration to rats OM-TMCD demonstrated a broad spectrum of anticonvulsant activity and showed better potency than VPA in the maximal electroshock seizure and subcutaneous pentylenetetrazole tests as well as in the hippocampal kindling model. OM-TMCD was inactive in the mouse 6-Hz test at 100 mg/kg dose. Teratogenicity studies performed in a SWV/Fnn-mouse model for VPA-induced-exencephaly showed that on the equimolar basis OM-TMCD possesses the same fetal toxicity and ability to induce NTDs as VPA, but since OM-TMCD is a much more potent anticonvulsant its activity/exencephaly formation ratio appears to be much more beneficial than that of VPA. OM-TMCD was found to be non-mutagenic and non-pro-mutagenic in the Ames test. It showed a beneficial pharmacokinetic profile in rats, having a high oral bioavailability of 75% and satisfactory values of clearance and volume of distribution. These results support further studies to fully characterize the therapeutic potential of OM-TMCD.

Clinical potential of milnacipran, a serotonin and norepinephrine reuptake inhibitor, in pain

Milnacipran is a serotonin (5-HT) and norepinephrine (NE) reuptake inhibitor currently available for use as an antidepressant in several countries. Phase III clinical trials are currently underway to assess its potential role in the treatment of fibromyalgia syndrome, and in pursuit of US Food and Drug Administration approval for this indication. Evidence has accumulated suggesting that in animal models, milnacipran may exert pain-mitigating influences involving NE- and 5-HT-related processes at supraspinal, spinal and peripheral levels of pain transmission. Preliminary evidence suggests that milnacipran may be useful in mitigating pain and fatigue associated with fibromyalgia. However, its role in addressing comorbidities associated with fibromyalgia, including visceral pain and migraine, has yet to be investigated.

The potential role of roflumilast: the new phosphodiesterase-4 inhibitor

OBJECTIVE

To review the pharmacology, pharmacokinetics, efficacy, and safety of roflumilast in the treatment of asthma and chronic obstructive pulmonary disease (COPD).

DATA SOURCES

Studies, review articles, and meeting abstracts evaluating roflumilast were obtained from MEDLINE (1966-May 16, 2006), EMBASE (1980-May 16, 2006), and International Pharmaceutical Abstracts (1970-May 16, 2006) databases. Key terms used in all of the database searches were roflumilast, phosphodiesterase-4 inhibitor, asthma, chronic obstructive pulmonary disease, and COPD. Company Web sites were reviewed, and bibliographies of selected articles were evaluated for pertinent articles.

STUDY SELECTION AND DATA EXTRACTION

In vitro, in vivo, and animal studies were selected, as were published human studies on the efficacy and safety of roflumilast. Due to limited published data on its safety, efficacy, pharmacokinetics, and drug interactions, meeting abstracts were also selected. Data retrieved from abstracts only is indicated in the references.

DATA SYNTHESIS

Roflumilast is a phosphodiesterase-4 (PDE-4) inhibitor which, due to its selective inhibition of the PDE 4 isoenzyme, has potential antiinflammatory and antimodulatory effects in the pulmonary system. It has been studied as an oral tablet in doses of 250 or 500 microg/day. Animal data and clinical trials have demonstrated roflumilast's efficacy and safety as an antiinflammatory and antimodulatory agent for use in asthma and COPD, with no documented drug interactions and a favorable adverse effect profile.

CONCLUSIONS

Roflumilast may be an additional option in the treatment of asthma and COPD due to its ease of administration and a seemingly favorable adverse event profile. However, more research is needed to solidify roflumilast's place in therapy.

Roflumilast: a selective phosphodiesterase 4 inhibitor

Roflumilast is a selective phosphodiesterase (PDE) 4 inhibitor with a range of anti-inflammatory properties and potential for treatment of inflammatory disease. The therapeutic effects of roflumilast are thought to be mediated via increased levels of cellular 3',5'-cyclic adenosine monophosphate (cAMP) and include inhibition of microvascular leakage, inhibition of trafficking, release of cytokines and chemokines from inflammatory cells, and bronchodilation. The anti-inflammatory and bronchodilator properties of roflumilast have resulted in clinical studies to investigate the effects of roflumilast in inflammatory airway diseases such as asthma and chronic obstructive pulmonary disease. In asthma, roflumilast taken as a once-daily oral dose of 500 ug has been shown to improve clinical symptoms and airway function, reduce exercise-induced asthma and decrease bronchial airway hyperresponsiveness. In chronic obstructive pulmonary disease, roflumilast taken as a once-daily oral dose of 500 ug has been shown to reduce the frequency of exacerbations with small effects on improving lung function. Side effects of roflumilast appear to be mild and short lasting. It is likely that this new class of selective PDE4 inhibitor may provide a therapeutic option for patients with inflammatory airway disease.

Remission Rates with Milnacipran 100??Mg/Day and 150 Mg/Day in??the??Long-Term Treatment of??Major Depression

BACKGROUND

The aim of this study was to determine remission rates during treatment with two different dosages of milnacipran, and the effect of milnacipran therapy for at least 1 year on the maintenance of remission and tolerability, in outpatients with major depression.

METHODS

The study included 41 outpatients with major depression who initially received milnacipran 50 mg/day for 1-2 weeks, followed by a dosage increase to 100 mg/day for 12 weeks. Patients who achieved remission (17-item Hamilton Depression Rating Scale [HDRS] scores <or=7) after 12 weeks of milnacipran 100 mg/day treatment continued at the same dosage and were followed for at least 1 year. For patients who had decreased HDRS scores, but failed to attain remission, the dosage of milnacipran was increased to 150 mg/day, and those who achieved remission were then followed for at least 1 year.

RESULTS

Eight out of 41 patients were withdrawn from the study prematurely because of adverse events (eight events in six patients: nausea, thirst, urinary discomfort, rapid pulse, palpitations, staggering sensation or sweating) or as a result of the patient's decision (two patients). Thirteen (31.7%) of 41 patients achieved remission during treatment with milnacipran 100 mg/day. Of the remaining 20 patients, 17 underwent a dosage increase to 150 mg/day, and 13 achieved remission at a second assessment (cumulative remission rate: 63.4%). No adverse events or recurrence of symptoms were found in any of the patients who achieved remission during the subsequent follow-up period of a minimum of 1 year.

CONCLUSIONS

The results of this study showed milnacipran 150 mg/day and 100 mg/day to be effective and well tolerated in the long-term treatment of outpatients with major depression, and indicated that a dosage of 150 mg/day is an effective therapeutic option for depression when a dosage of 100 mg/day does not provide a satisfactory response.

Efficacy of milnacipran on poststroke depression on inpatient rehabilitation

Post-stroke depression (PSD) has a negative impact on rehabilitation following stroke. No satisfactory antidepressant treatment for PSD has yet been developed. The present study examined the effect of milnacipran, a serotonin and norepinephrine reuptake inhibitor, on PSD patients. Eleven PSD patients taking milnacipran in a rehabilitation hospital were compared to age-matched, sex-matched, and severity of depression at admission-matched PSD patients hospitalized during 2001 who did not take any antidepressant as historical control. Severity of depression was measured using self-rating depression scale for depression (SDS) assessed at admission and discharge after 3 months inpatient rehabilitation. Activities of daily living (ADL) and quality of life (QOL) were measured, respectively, by the functional independence measure (FIM) and a self-completed questionnaire for QOL (QUIK) as outcomes of rehabilitation. For the SDS score, the group taking milnacipran showed significant improvement compared to the control group in our study. FIM was improved in both groups. In the end QUIK did not change significantly in either group. We found no major side-effects of milnacipran among the patients. These results suggest that milnacipran is a safe and effective treatment for PSD for inpatients undergoing rehabilitation.

Roflumilast for asthma and chronic obstructive pulmonary disease

Roflumilast is an inhibitor of phosphodiesterase- IV (PDE4), a cellular enzyme that is linked to airway inflammation in asthma and chronic obstructive pulmonary disease (COPD). In clinical trials, roflumilast produced significant improvements in FEV1 (forced expiratory volume in one second) and PEF (peak expiratory flow) compared with low-dose inhaled beclomethasone in asthma patients, and compared with placebo in COPD patients. Roflumilast reduced the use of rescue medication in both populations. COPD patients on roflumilast experienced fewer exacerbations. The most common adverse effects reported in roflumilast trials were diarrhea, nausea, headache, and abdominal pain. Evidence is only available in non-peer-reviewed format abstracts. Most of the measures used are markers of clinical effects as opposed to clinical outcomes. More studies are needed to determine the role of roflumilast in the treatment of asthma and COPD.

SNRIs: their pharmacology, clinical efficacy, and tolerability in comparison with other classes of antidepressants

The class of serotonin and norepinephrine reuptake inhibitors (SNRIs) now comprises three medications: venlafaxine, milnacipran, and duloxetine. These drugs block the reuptake of both serotonin (5-HT) and norepinephrine with differing selectivity. Whereas milnacipran blocks 5-HT and norepinephrine reuptake with equal affinity, duloxetine has a 10-fold selectivity for 5-HT and venlafaxine a 30-fold selectivity for 5-HT. All three SNRIs are efficacious in treating a variety of anxiety disorders. There is no evidence for major differences between SNRIs and SSRIs in their efficacy in treating anxiety disorders. In contrast to SSRIs, which are generally ineffective in treating chronic pain, all three SNRIs seem to be helpful in relieving chronic pain associated with and independent of depression. Tolerability of an SNRI at therapeutic doses varies within the class. Although no direct comparative data are available, venlafaxine seems to be the least well-tolerated, combining serotonergic adverse effects (nausea, sexual dysfunction, withdrawal problems) with a dose-dependent cardiovascular phenomenon, principally hypertension. Duloxetine and milnacipran appear better tolerated and essentially devoid of cardiovascular toxicity.

Roflumilast, an oral, once-daily phosphodiesterase 4 inhibitor, attenuates allergen-induced asthmatic reactions

BACKGROUND

Asthma is a chronic inflammatory disease with increasing incidence worldwide. Roflumilast is an oral, once-daily inhibitor of phosphodiesterase type 4 that prevents the breakdown of cyclic adenosine monophosphate levels, leading to inhibition of proinflammatory signaling.

OBJECTIVE

The objective of this study was to investigate the effects of repeated doses of 250 or 500 microg of roflumilast on asthmatic airway responses to allergen.

METHODS

Twenty-three patients with mild asthma with an FEV1 of 70% of predicted value or greater were enrolled in a randomized, double-blind, placebo-controlled, 3-period crossover study. Patients participated in 3 treatment periods (7-10 days) separated by washout periods (2-5 weeks). Patients received 250 microg of oral roflumilast, 500 microg of roflumilast, or placebo once daily. Allergen challenge was performed at the end of each treatment period, followed by FEV1 measurements over the ensuing 24 hours.

RESULTS

Late asthmatic reactions (LARs) were reduced by 27% (P = .0110) and 43% (P = .0009) in patients treated with 250 and 500 microg of roflumilast, respectively, versus placebo. Roflumilast, 250 and 500 microg, also attenuated early asthmatic reactions by 25% (P = .0038) and 28% (P = .0046), although not to the same extent as LAR attenuation. Roflumilast was well tolerated. No serious adverse events or discontinuations caused by adverse events were reported.

CONCLUSION

Once-daily oral roflumilast modestly attenuated early asthmatic reactions and, to a greater extent, LARs to allergen in patients with mild allergic asthma. Pronounced suppression of late responses in an allergen challenge model suggests that roflumilast might have anti-inflammatory activity, which could provide clinical efficacy in chronic inflammatory pulmonary diseases, such as asthma.

A comparative study of milnacipran and paroxetine in outpatients with major depression

BACKGROUND

Milnacipran is a dual-action antidepressant which inhibits both serotonin and noradrenaline reuptake with no affinity for any neurotransmitter receptor studied.

METHODS

A 6-week double-blind multicentre study compared milnacipran (100 mg/day) with paroxetine (20 mg/day) in 300 outpatients with major depression. Efficacy was evaluated using HAMD17, MADRS and CGI for severity of illness and global improvement. Data were analysed on an intention to treat, last observation carried forward, basis.

RESULTS

Milnacipran and paroxetine were both effective and well tolerated with no significant difference in their effects. After treatment discontinuation, milnacipran was associated with significantly less emergent symptoms. Responders, at endpoint, to milnacipran had significantly greater levels of psychomotor retardation at baseline than non-responders.

LIMITATIONS

The study did not include a placebo group so that it is impossible to determine absolute levels of efficacy.

CONCLUSIONS

Both milnacipran and paroxetine were effective and well tolerated by outpatients with major depression treated for 6 weeks. After treatment discontinuation milnacipran was associated with less emergent symptoms. Psychomotor retardation at baseline may be a predictive factor of a favourable response to milnacipran.

Controlled comparison of two different doses of milnacipran in major depressive outpatients

We compared the antidepressant efficacy and patient tolerance of two different doses of milnacipran (75 mg and 150 mg daily) in 66 outpatients with major depression, using the 17-item Hamilton Depression Rating Scale (HDRS). Only new patients who had never experienced frank depressive episodes before, or those who had remained free from thymoregulators for more than 1 year without recurrence of depressive symptoms, were recruited. Subjects were randomly selected to receive a daily dose of milnacipran that reached either 75 mg or 150 mg within 2-3 weeks and then remained stable over an 8-week period. The results showed a significant superiority of milnacipran at 150 mg/day over 75 mg/day at the end of the study period in both response (50% or more decrease in total score from baseline, P=0.026) and remission (total HDRS score lower than 7 points, P=0.034). A response was recorded for 56.0% of the patients treated with 75 mg of milnacipran and for 84.6% of those treated with 150 mg after the 8-week study period. No significant difference was seen between the treatment groups for either individual or total incidence of adverse events. Notably, nausea and vomiting occurred most often immediately after the first visit, when subjects in both groups started with a daily dose of 50 mg. We conclude that additional comparisons between different doses of milnacipran should be performed to confirm or deny the linear dose/efficacy relationship observed in the present study.

A double-blind placebo-controlled trial of milnacipran in the treatment of fibromyalgia

Fibromyalgia syndrome is a systemic disorder of widespread pain which is thought to result from abnormal pain processing within the central nervous system. There are no currently approved treatments for this indication. Antidepressants appear, however, to be effective, especially those with an action on noradrenergic neurotransmission. The objective of the present study was to test the efficacy of the dual action noradrenaline and serotonin reuptake inhibitor antidepressant, milnacipran, in the treatment of fibromyalgia. The 125 patients, who were enrolled in a double-blind, placebo-controlled, flexible dose escalation trial, were randomized to receive placebo or milnacipran for 4 weeks of dose escalation (up to 200 mg/day), followed by 8 weeks at a constant dose. The study evaluated the efficacy and safety of milnacipran for the treatment of pain and associated symptoms such as fatigue, depressed mood and sleep. 75% of milnacipran-treated patients reported overall improvement, compared with 38% in the placebo group (p < 0.01). Furthermore, 37% of twice daily milnacipran-treated patients reported at least 50% reduction in pain intensity, compared with 14% of placebo-treated patients (p < 0.05). 84% of all milnacipran patients escalated to the highest dose (200 mg/day) with no tolerability issues. Most adverse events were mild to moderate in intensity, and transient in duration. These results suggest that milnacipran may have the potential to relieve not only pain but several of the other symptoms associated with fibromyalgia.

Effectiveness of Milnacipran for the Treatment of Chronic Pain

Milnacipran is a novel serotonin noradrenaline reuptake inhibitor. The authors describe the use of milnacipran for the treatment of chronic pain in a series of patients. There were 5 outpatients who suffered chronic pain for at least 3 months. None of these patients met the DSM-IV criteria for a major depressive disorder. Chronic pain was assessed clinically by means of a visual analog scale (VAS) before and 12 weeks after the start of the milnacipran treatment or at the time the drug was stopped. The duration of pain was 17.8 +/- 9.3 months (mean +/- SD), and the baseline VAS score was 88.2 +/- 6.3 points. Milnacipran was administered at 50 to 150 mg/day, and the dose at 12 weeks or at the time the drug was stopped was 85.0 +/- 31.3 mg/day. The mean +/- SD decrease in VAS at this time was 61.2 +/- 15.5%. Three patients showed marked improvement (decrease in VAS, >75%). Their decreases in VAS scores were 86.5%, 85.7%, and 77.6%. One patient showed mild improvement (42.0% decrease in VAS). These 4 patients tolerated the drug well. The fifth patient experienced nausea and discontinued treatment after 4 weeks. The VAS decrease for this patient was 14.3%. Results of this study show milnacipran to be beneficial in patients with chronic pain. This drug should be studied further for its effectiveness in the treatment of chronic pain.

Subjective and polysomnographic effects of milnacipran on sleep in depressed patients

The effects of milnacipran (50 mg bid) on sleep patterns of eight depressed inpatients, treated for 4 weeks, were studied during the initial (days 1-3) and terminal (days 26-28) treatment periods and compared with those obtained from three sleep recordings performed just prior to the initiation of the treatment. The clinical evolution of patients was evaluated weekly using the MADRS depression scale and the Spiegel and Norris sleep scales. Clinical improvement, shown by a mean reduction of 58% in MADRS scale scores, was accompanied by an improvement of disturbed sleep parameters. From the beginning of treatment, there was an increase in the total duration of sleep and stage II sleep, a decrease in sleep latency and an increase in sleep efficiency. Total REM sleep was not modified although, since there was an increase in total sleep time, the percent REM sleep was significantly reduced. REM latency was increased early in the study, an effect classically associated with antidepressant treatment. This study suggests that milnacipran improves disturbed sleep parameters in depressed patients without any additional disturbance at the onset of treatment.