Antihypertensive, insulin-sensitising and renoprotective effects of a novel, potent and long-acting angiotensin II type 1 receptor blocker, azilsartan medoxomil, in rat and dog models

The pharmacological profile of a novel angiotensin II type 1 receptor blocker, azilsartan medoxomil, was compared with that of the potent angiotensin II receptor blocker olmesartan medoxomil. Azilsartan, the active metabolite of azilsartan medoxomil, inhibited the binding of [(125)I]-Sar(1)-I1e(8)-angiotensin II to angiotensin II type 1 receptors. Azilsartan medoxomil inhibited angiotensin II-induced pressor responses in rats, and its inhibitory effects lasted 24h after oral administration. The inhibitory effects of olmesartan medoxomil disappeared within 24h. ID(50) values were 0.12 and 0.55 mg/kg for azilsartan medoxomil and olmesartan medoxomil, respectively. In conscious spontaneously hypertensive rats (SHRs), oral administration of 0.1-1mg/kg azilsartan medoxomil significantly reduced blood pressure at all doses even 24h after dosing. Oral administration of 0.1-3mg/kg olmesartan medoxomil also reduced blood pressure; however, only the two highest doses significantly reduced blood pressure 24h after dosing. ED(25) values were 0.41 and 1.3mg/kg for azilsartan medoxomil and olmesartan medoxomil, respectively. In renal hypertensive dogs, oral administration of 0.1-1mg/kg azilsartan medoxomil reduced blood pressure more potently and persistently than that of 0.3-3mg/kg olmesartan medoxomil. In a 2-week study in SHRs, azilsartan medoxomil showed more stable antihypertensive effects than olmesartan medoxomil and improved the glucose infusion rate, an indicator of insulin sensitivity, more potently (≥ 10 times) than olmesartan medoxomil. Azilsartan medoxomil also exerted more potent antiproteinuric effects than olmesartan medoxomil in Wistar fatty rats. These results suggest that azilsartan medoxomil is a potent angiotensin II receptor blocker that has an attractive pharmacological profile as an antihypertensive agent.     

Pharmacological profiles and clinical effects of olmesartan medoxomil, a novel angiotensin II receptor blocker

Olmesartan medoxomil is a new angiotensin II receptor blocker (ARB) indicated for the treatment of hypertension. Olmesartan medoxomil is a pro-drug that is converted to the active metabolite olmesartan. Olmesartan does not undergo further metabolism and does not interact with cytochrome P450 enzymes. Olmesartan is a potent ARB with high selectivity for the type 1 (AT(1)) receptor subtype and shows insurmountable antagonism against the AT(1) receptor in vascular tissues. This antagonistic mode, which could be attributed to tight binding of this drug to the receptor, would underlie the potent and persistent action of olmesartan medoxomil in vivo. In fact, oral administration of olmesartan medoxomil produces a potent and long-lasting antihypertensive action without inducing tachycardia. The preventive effects of olmesartan medoxomil on end-organ damage in the kidney, heart, and blood vessels have been demonstrated in various animal models. In clinical studies, olmesartan medoxomil is shown to be well tolerated and have an excellent safety profile that is comparable to that of placebo. Head-to-head comparisons with other ARBs (losartan, valsartan, irbesartan, and candesartan cilexetil) conducted in the United States and Europe have revealed that olmesartan medoxomil is superior to these other ARBs in lowering blood pressure. These facts suggest that olmesartan medoxomil would be beneficial for the treatment of hypertension and other end-organ diseases.     

Anticoagulation with anisindione in a patient with a warfarin-induced skin eruption

A 71-year-old woman experienced a pruritic, maculopapular, morbilliform rash on her lower extremities 5 days after starting warfarin for recurrent deep vein thrombosis. The rash extended to her truncal areas and progressively worsened until somewhat painful vesicular lesions developed. Warfarin was discontinued, and subcutaneous injections of enoxaparin were begun; the rash resolved. In addition to a history of deep vein thrombosis, the patient had experienced a hypersensitivity skin reaction to warfarin in the past that necessitated withdrawal of the drug and placement of a vena caval filter. Because no clear consensus exists on whether dyes used in compounding warfarin play a causative role or whether allergic cross-sensitivity occurs among the coumarin derivatives, the patient was rechallenged with a dye-free warfarin 10-mg tablet. The pruritic rash returned along with the vesicular lesions and continued to worsen until the warfarin was discontinued again. The patient subsequently was given oral anticoagulant therapy with anisindione, an indanedione, and her symptoms resolved completely. Health care providers managing patients who are receiving oral anticoagulant therapy should be aware of the maculopapular allergic reactions associated with warfarin and consider alternative treatment options such as anisindione.     

A rare case of imatinib-induced erythroderma

Imatinib, a specific tyrosine kinase inhibitor is a newer anticancer agent, which has shown excellent efficacy in managing chronic myeloid leukemia. It is generally well tolerated with few side effects. Most commonly reported adverse events are maculopapular eruptions and periorbital edema. Severe adverse reactions are seen in 5% of patients. Exfoliative dermatitis has been very rarely reported with this drug. We report a case of a 52-year-old male who initially presented with a maculopapular rash and developed erythroderma on continuation of the drug.KEY WORDS: Adverse cutaneous drug reaction, erythroderma, Imatinib     

Hypersensitivity due to ceftriaxone mimicking measles in a child

Ceftriaxone is a commonly used antibiotic in children for various infections like respiratory tract infection, urinary tract infection and enteric fever. Hypersensitive reactions following ceftriaxone therapy are uncommon but are potentially life-threatening. The rash can resemble viral exanthems and may lead to a delay in the recognition and prompt treatment. Here we report a 7-year-old boy who presented with fever and rash with emphasis on recognizing ceftriaxone hypersensitivity and its management.KEY WORDS: Ceftriaxone allergy, child, hypersensitivity, maculopapular rash     

Azilsartan medoxomil: a review of its use in hypertension

Azilsartan medoxomil (Edarbi?; Ipreziv?) is an orally administered angiotensin II receptor type 1 antagonist (blocker) used in the treatment of adults with essential hypertension. This article reviews data on the clinical efficacy and tolerability of azilsartan medoxomil in adults with essential hypertension and provides a summary of its pharmacological properties. Azilsartan medoxomil is a prodrug that undergoes rapid hydrolysis in the gastrointestinal tract after oral administration to the bioactive moiety azilsartan, before systemic absorption. Azilsartan medoxomil produces antihypertensive effects by selectively blocking the binding of angiotensin II to the angiotensin type 1 (AT(1)) receptor, thereby antagonizing the pressor response activity of angiotensin II. In vitro, azilsartan produced greater and more sustained AT(1) receptor binding/blockade activity than several comparator angiotensin II receptor antagonists. Azilsartan medoxomil reduces blood pressure (BP) in hypertensive adults. In addition, the drug has been shown to have pleiotropic effects (i.e. effects beyond AT(1) receptor blockade). In adults with essential hypertension, azilsartan medoxomil 20, 40 or 80?mg effectively reduced BP over a 24-hour period with once-daily administration in three major, randomized, controlled trials in which the primary endpoints were changes from baseline in 24-hour mean systolic BP (SBP) at week 6 (two trials) or week 24, assessed by ambulatory BP monitoring (ABPM). In the two 6-week trials, azilsartan medoxomil showed dose-dependent efficacy over all evaluated dosages and was more effective than placebo in lowering SBP. At the maximum approved dosage of 80?mg once daily, azilsartan medoxomil was significantly more effective than maximum dosages of olmesartan medoxomil (40?mg once daily) or valsartan (320?mg once daily), based on primary endpoint assessments. Mean reductions in clinic measurements of SBP and diastolic BP (DBP) measurements were also generally greater with azilsartan medoxomil 80?mg once daily than with the comparator drugs in these 6-week studies. Over a longer treatment period of 24 weeks, azilsartan medoxomil showed sustained BP-lowering efficacy, with the reduction in 24-hour mean SBP at week 24 significantly greater with azilsartan medoxomil 40 or 80?mg once daily than with valsartan 320?mg once daily. Mean reductions from baseline in mean clinic SBP and DBP as well as DBP by ABPM were also significantly greater with azilsartan medoxomil 40 or 80?mg once daily than with valsartan. Azilsartan medoxomil was generally well tolerated, with a tolerability profile similar to that of placebo in the 6-week trials. Across the three major trials, headache and dizziness were among the most common adverse events. Overall, rates of treatment discontinuation as a result of adverse events were low in the 6-week and 24-week trials. In conclusion, once-daily azilsartan medoxomil effectively lowers BP in adults with essential hypertension and has shown better antihypertensive efficacy than maximum therapeutic dosages of olmesartan medoxomil or valsartan in major trials of up to 24 weeks' duration. Azilsartan medoxomil is generally well tolerated and the low rates of discontinuation due to adverse events suggest that patients are likely to persist with long-term treatment. Azilsartan medoxomil is therefore a useful and attractive new option for lowering BP in patients with essential hypertension, particularly for those not able to tolerate other antihypertensive drugs. Further studies are required to evaluate the effects of azilsartan medoxomil on cardiovascular morbidity and mortality.     

Recognising antibacterial hypersensitivity in children

Adverse reactions to antibacterial agents are not uncommon in children. They are classified as 'immediate' or 'nonimmediate' according to the time interval between drug administration and onset. Immediate reactions occur within 1 hour and are manifested by urticaria and/or angioedema, bronchospasm and anaphylactic shock; immunological reactions are mediated by IgE antibodies. The main nonimmediate reactions (occuring after more than 1 hour) are maculopapular rash, urticaria and serum sickness; T lymphocytes may participate in maculopapular rash. Clinical assessment of such reactions is complex. The patient's history is fundamental; the allergological examination includes in vivo and in vitro tests selected on the basis of the clinical features and the phase of reaction. In the late phase, prick and intradermal tests are sensitive in evaluating beta-lactam allergy. Together with delayed-reading intradermal testing, patch testing seems to be useful in diagnosing maculopapular reactions to systemically administered aminopenicillins. Determination of specific IgE levels is the most common in vitro method for diagnosing immediate reactions. In the acute phase, serum tryptase and urinary N-methylhistamine assays are reliable in diagnosing type I pathogenic mechanisms in immediate reactions. Unfortunately, there are few in vitro tests for evaluating other reactions, and most are not fully validated. In selected cases, provocation tests should be performed.     

Murine typhus in Kaukapakapa?

We report a patient who had not been outside New Zealand with a fever and maculopapular rash. Serology suggested acute murine typhus due to R typhi. This is the first reported case in New Zealand from a nontraveller.     

Incidence and management of cutaneous toxicities associated with cetuximab

Cetuximab is a human/mouse chimeric monoclonal antibody that binds to the EGF receptor, competitively inhibiting ligand binding, and inducing receptor dimerization and downregulation. Cetuximab has been active in multiple tumors, including colorectal cancer (CRC), head and neck, pancreatic and lung cancers. Cetuximab has been approved by the FDA, in combination with irinotecan, for the treatment of metastatic CRC in patients refractory to irinotecan, and for use as a single agent in the treatment of recurrent metastatic CRC in patients intolerant of irinotecan-based chemotherapy. Most common toxicities are rash, diarrhea, fever, headache, nausea, hypomagnesemia and hypersensitivity reactions. Data from several clinical trials with cetuximab show a positive correlation between rash and response and/or survival. Rash occurred on 90% of patients treated with cetuximab monotherapy and grade 3 or 4 skin reactions occurred on as many as 16% of patients in the trials using cetuximab. A rash usually presents as pustular or maculopapular follicular eruption, often referred to as acneiform. Cetuximab will engage in productive dimerization complexes in human skin causing significant disruption of the normal development and maintenance of the hair follicle, which leads to follicular response and inflammatory response. At this time there are no standard or evidence-based treatment plans for the rash. Most of the evidence is based on institutional or personal experiences. The most commonly used agents are topical antibiotics, oral antibiotics, topical steroids, systemic immunomodulatory agents, topical immunomodulatory agents and anti-inflammatory preparations. As cetuximab is becoming widely used in general oncology practice, it is important to understand the toxicity of rash to develop practice guidelines for their management. This review addresses recommendations for toxicity management of rash caused by cetuximab in treatment of metatstatic CRC.     

Olmesartan medoxomil

Olmesartan medoxomil is a nonpeptide angiotensin II receptor antagonist which selectively and competitively inhibits the type 1 angiotensin II receptor without affecting other receptors regulating the cardiovascular system. In well designed randomised trials, olmesartan medoxomil was significantly more effective than placebo, and at dosages of 10 to 20 mg/day was at least as effective as atenolol 50 to 100 mg/day in reducing diastolic blood pressure (DBP). At dosages of 5 to 20 mg/day, olmesartan medoxomil was more effective than captopril 12.5 to 50mg twice daily at lowering seated DBP in patients with mild to moderate hypertension in a dose titration study. Reductions in seated DBP were greater with olmesartan medoxomil 10 to 20 mg/day than losartan 50 to 100 mg/day. Olmesartan medoxomil at 20 mg/day was more effective in lowering seated DBP than losartan 50 mg/day, valsartan 80 mg/day or irbesartan 150 mg/day, and was more efficacious than losartan 50 mg/day or valsartan 80 mg/day at reducing 24-hour ambulatory systolic blood pressure. Olmesartan medoxomil has shown no clinically important pharmacokinetic interactions with digoxin, warfarin or antacid (aluminium magnesium hydroxide). Adverse events were infrequent in clinical studies of olmesartan medoxomil and were similar to those attributed to placebo. With olmesartan medoxomil, the frequency of dizziness was higher than with placebo but similar to that occurring with losartan, valsartan and irbesartan.     

Incidence and management of cutaneous toxicities associated with cetuximab

Cetuximab is a human/mouse chimeric monoclonal antibody that binds to the EGF receptor, competitively inhibiting ligand binding, and inducing receptor dimerization and downregulation. Cetuximab has been active in multiple tumors, including colorectal cancer (CRC), head and neck, pancreatic and lung cancers. Cetuximab has been approved by the FDA, in combination with irinotecan, for the treatment of metastatic CRC in patients refractory to irinotecan, and for use as a single agent in the treatment of recurrent metastatic CRC in patients intolerant of irinotecan-based chemotherapy. Most common toxicities are rash, diarrhea, fever, headache, nausea, hypomagnesemia and hypersensitivity reactions. Data from several clinical trials with cetuximab show a positive correlation between rash and response and/or survival. Rash occurred on 90% of patients treated with cetuximab monotherapy and grade 3 or 4 skin reactions occurred on as many as 16% of patients in the trials using cetuximab. A rash usually presents as pustular or maculopapular follicular eruption, often referred to as acneiform. Cetuximab will engage in productive dimerization complexes in human skin causing significant disruption of the normal development and maintenance of the hair follicle, which leads to follicular response and inflammatory response. At this time there are no standard or evidence-based treatment plans for the rash. Most of the evidence is based on institutional or personal experiences. The most commonly used agents are topical antibiotics, oral antibiotics, topical steroids, systemic immunomodulatory agents, topical immunomodulatory agents and anti-inflammatory preparations. As cetuximab is becoming widely used in general oncology practice, it is important to understand the toxicity of rash to develop practice guidelines for their management. This review addresses recommendations for toxicity management of rash caused by cetuximab in treatment of metatstatic CRC.     

Clinical and experimental aspects of olmesartan medoxomil, a new angiotensin II receptor antagonist

Olmesartan medoxomil is a new orally active angiotensin II (Ang II) type 1 receptor antagonist. It is a prodrug and is rapidly de-esterified during absorption to form olmesartan, the active metabolite. Olmesartan is a potent, competitive and selective Ang II type 1 receptor antagonist. Olmesartan is not metabolized by the cytochrome P-450 and has a dual route of elimination, by kidneys and liver. In patients with essential hypertension olmesartan medoxomil administered once daily at doses of 10-80 mg dose-dependently reduced diastolic blood pressure (DBP). Troughto-peak ratios for both DBP and systolic blood pressure (SBP) were above 50%. At the recommended once-daily starting doses, olmesartan medoxomil (20 mg) was more effective than losartan (50 mg), valsartan (80 mg) or irbesartan (150 mg) in reducing cuff DBP in patients with essential hypertension. The results of cuff SBP and mean 24-h DBP and SBP were similar to those of cuff DBP measurement. In mild-to-moderate hypertensive patients the recommended starting dose of olmesartan medoxomil was as effective as that of amlodipine besylate (5 mg/day) in reducing both cuff and 24-h blood pressure. In lowering DBP olmesartan medoxomil, at 10-20 mg/day, was as effective as atenolol at 50-100 mg/day. In mild-to-moderate hypertensive patients, olmesartan medoxomil, at 5-20 mg once daily, was more effective than captopril at 12.5-50 mg twice daily. At 20-40 mg once daily olmesartan medoxomil was as effective as felodipine, at 5-10 mg once daily. Olmesartan medoxomil has minimal adverse effects with no clinically important drug interactions. Animal studies have shown that olmesartan medoxomil provides a wide range of organ protection. Olmesartan medoxomil ameliorated atherosclerosis in hyperlipidemic animals and ameliorated cardiac remodeling and improved survival in rats with myocardial infarction. Olmesartan medoxomil has renoprotective effects in a remnant kidney model and type 2 diabetes models. Future investigation should reveal whether these beneficial effects of olmesartan medoxomil are applicable to human diseases.     

左乙拉西坦致皮疹2例

2例女性癫痫患者(例1 15岁,例2 54岁),服用传统抗癫痫药物效果不佳,给予口服左乙拉西坦0.25 g2,次/d,分别在治疗第75、天,四肢及躯干部皮肤出现红色斑疹伴瘙痒。考虑皮疹与左乙拉西坦有关。例1停用左乙拉西坦后3 d皮疹消褪。例2停用左乙拉西坦并接受氯雷他定10 mg、1次/d治疗,1周后皮疹消褪。     

小牛血清去蛋白注射液致广泛斑丘疹1例

1例48岁男性患者,静脉滴注小牛血清去蛋白注射液后出现广泛斑丘疹,予以报道,提醒临床使用该药时注意该种不良反应的发生。     

The sunny side of lime

A 26-year-old woman was affected with a maculopapular rash because of a jellyfish sting on her right leg while surfing in Indonesia. A locally-prepared liniment was applied on the affected skin. She presented with hyperpigmented linear tracks that she noted a few days later.     

卡马西平致全身大疱性表皮松解

1例66岁男性患者因三叉神经痛服用卡马西平100 mg,2次/d。服药第10天出现全身皮疹伴瘙痒、触痛。5 d后其症状发展为眼睑、鼻腔、口唇和口腔黏膜破溃、糜烂以及躯干、四肢弥漫性斑丘疹和尼氏征阳性。诊断为药物所致大疱性表皮松解。停用卡马西平,给予甲泼尼龙、人免疫球蛋白、人血白蛋白、阿奇霉素及环磷酰胺等治疗,10 d后皮疹基本消退。     

Oral mucosal involvement and petechial lesions: a SDRIFE case with unusual findings

Symmetrical drug-related intertriginous and flexural exanthema (SDRIFE) is a type IV hypersensitivity reaction characterized by a symmetrical erythematous rash in the gluteal and intertriginous areas. SDRIFE was previously considered to be the same presentation as Baboon Syndrome, however, has been suggested to be a different entity in the recent publications. The lesions are generally maculopapular and there is no mucosal involvement. To date, no case with petechial findings and mucosal involvement has been reported in the literature. The present study reports a SDRIFE case with a symmetrical erythematous petechial rash and oral mucosal involvement after taking oral amoxicillin.     

Olmesartan medoxomil: a review of its use in the management of hypertension

Olmesartan medoxomil (Olmetec, Benicar) is an angiotensin II type 1 (AT(1)) receptor antagonist (angiotensin receptor blocker [ARB]) that inhibits the actions of angiotensin II on the renin-angiotensin-aldosterone system, which plays a key role in the pathogenesis of hypertension. Oral olmesartan medoxomil 10-40 mg once daily is recommended for the treatment of adult patients with hypertension. In those with inadequate BP control using monotherapy, fixed-dose olmesartan medoxomil/hydrochlorothiazide (HCTZ) [Olmetec plus, Benicar-HCT] combination therapy may be initiated. Extensive clinical evidence from several large well designed trials and the clinical practice setting has confirmed the antihypertensive efficacy and good tolerability profile of oral olmesartan medoxomil, as monotherapy or in combination with HCTZ, in patients with hypertension, including elderly patients with isolated systolic hypertension (ISH). Notably, BP control is sustained throughout the 24-hour dosage interval, including during the last 4 hours of this period. In clinical trials, olmesartan medoxomil monotherapy provided better antihypertensive efficacy than losartan, candesartan cilexetil or irbesartan monotherapy, and was at least as effective as valsartan treatment, with a faster onset of action than other ARBs in terms of reductions from baseline in diastolic BP (DBP) and, in most instances, systolic BP (SBP). Combination therapy with olmesartan medoxomil plus HCTZ was superior to that with benazepril plus amlodipine, as effective as that with losartan plus HCTZ, noninferior to that with atenolol plus HCTZ, but less effective than that with telmisartan plus HCTZ, in individual trials. Data from ongoing clinical outcome trials are required to more fully determine the relative position of olmesartan medoxomil therapy in the management of hypertension. In the meantime, the consistent antihypertensive efficacy during the entire 24-hour dosage interval and good tolerability profile of olmesartan medoxomil, with or without HCTZ, make it a valuable option for the treatment of adult patients with hypertension, including the elderly.     

心血管疾病新药阿齐沙坦酯的药理与临床评价

阿齐沙坦酯(azilsartan medoxomil)是一种血管紧张素II受体拮抗剂,用于治疗高血压,可与其他抗高血压药物联用。本文参照美国FDA有关该药的申报资料,对其药理作用、药代动力学、临床评价、安全性评价及药物相互作用等进行综述。     

Azilsartan medoxomil for the treatment of hypertension

The use of angiotensin receptor blockers (ARBs) represents a favorable approach for the control of blood pressure in patients with hypertension. Azilsartan medoxomil, a prodrug that undergoes rapid hydrolysis to its active moiety azilsartan, is an angiotensin AT(1) receptor antagonist with promising antihypertensive activity and a good safety profile. The agent has been evaluated as monotherapy and in combination with amlodipine or chlorthalidone in phase III trials in patients with essential hypertension. In 2011, azilsartan medoxomil was approved in the U.S. for the treatment of hypertension.