英文药名: Dipentum(Olsalazine)

中文药名: 奥沙拉嗪,奥柳氮,地泊坦

品牌药生产厂家: UCB Pharma Inc.

药品名称

通用名称：奥沙拉秦
英文名：Olsalazine
其它中文名：奥柳氮钠、奥沙拉嗪、地泊坦
其它英文名：Azodisat Sodium、Dipentum、Disodium Azobis
药理作用

治疗溃疡性结肠炎常用柳氮磺吡啶，其不良反应发生率约20％，不少病例因而减量或中止治疗。柳氮磺吡啶在结肠内能被结肠内细菌分解为5-氨基水杨酸(5-ASA)和磺胺吡啶，现已证实磺胺吡啶并无活性，而且可引起不良反应。5-氨基水杨酸则为有效成分，它作用于炎症粘膜，可抑制引起炎症的前列腺素的合成，抑制增强细胞膜通透性，引起水肿的炎症介质白三烯形成。但口服5-氨基水杨酸无效，因它在小肠中吸收迅速，然后即被乙酰化并随尿排出，不能达到结肠部位。奥柳氮钠用活性成分5-氨基水杨酸替代并无作用的磺胺吡啶，已证实奥柳氮钠在胃和小肠内不被吸收也不被分解，到达结肠后才被结肠内细菌分裂为二分子有效的5-氨基水杨酸而显示其抗炎作用。 5-氨基水杨酸是治疗溃疡性结肠炎的有效成分，但口服5-氨基水杨酸后在小肠被吸收，乙酰化后随尿排出，不能到达结肠部位。本品在胃及小肠中不被吸收也不分解，到达结肠部位后其偶氮键在细菌作用下断裂，分解为2分子5-氨基水杨酸并作用于结肠炎症粘膜，抑制前列腺素合成，抑制炎症介质白三烯的形成，降低肠壁细胞膜的通透性，减轻肠粘膜水肿，发挥抗炎作用。
适应症　　

用于急、慢性溃疡性结肠炎与节段性回肠炎及其缓解期的长期维持治疗。
用法用量　　

口服，治疗开始时成人日剂量1500mg，饭后分3次服，必要时日剂量可增加至3000mg；儿童日剂量20～40mg/kg。维持治疗成人日剂量1000mg，分2次服；儿童日剂量15～30mg/kg。炎症性肠炎〔溃疡性肠炎、克罗恩病(节段性回肠炎)]及其缓解期的长期维持治疗。开始剂量为lg•d－1，分次口服，以后逐渐增至3g•d-1，分3-4次服用。
儿童剂量为20-40mg•kg－1•d－1。长期维持治疗时成人剂量为0．5g•d-1，分2次服用。本品应在进餐时伴服。或遵医嘱！
禁用/慎用

小儿不推荐服用；水杨酸过敏者、严重肾损害及孕妇禁用。
不良反应　

软便、腹泻、消化不良、头痛、恶心、关节痛、皮疹，失眠等。
注意事项

禁用于对水杨酸过敏者、肾功能严重不全者及孕妇。有胃肠道反应者慎用。一旦发现漏服可立即补服，但不要在同一时间用2倍剂量。孕妇用药安全性尚未确立，哺乳期妇女用药也缺乏临床经验，应慎用。对水杨酸过敏者、严重肝肾功能损害者禁用。

包装规格
·250mg *112 胶囊
·500mg 60 片

DIPENTUM (olsalazine sodium) capsule, gelatin coated
[Alaven Pharmaceutical LLC]

Rx Only

DESCRIPTION

The active ingredient in DIPENTUM Capsules (olsalazine sodium) is the sodium salt of a salicylate, disodium 3,3'-azobis (6-hydroxybenzoate) a compound that is effectively bioconverted to 5-aminosalicylic acid (5-ASA), which has anti-inflammatory activity in ulcerative colitis. Its empirical formula is C14H8N2Na2O6 with a molecular weight of 346.21.

The structural formula is:

Olsalazine sodium is a yellow crystalline powder, which melts with decomposition at 240°C. It is the sodium salt of a weak acid, soluble in water and DMSO, and practically insoluble in ethanol, chloroform, and ether. Olsalazine sodium has acceptable stability under acidic or basic conditions.

DIPENTUM is supplied in hard gelatin capsules for oral administration. The inert ingredient in each 250 mg capsule of olsalazine sodium is magnesium stearate. The capsule shell contains the following inactive ingredients: black iron oxide, caramel, gelatin, and titanium dioxide.

CLINICAL PHARMACOLOGY

After oral administration, olsalazine has limited systemic bioavailability. Based on oral and intravenous dosing studies, approximately 2.4% of a single 1.0 g oral dose is absorbed. Less than 1% of olsalazine is recovered in the urine. The remaining 98 to 99% of an oral dose will reach the colon, where each molecule is rapidly converted into two molecules of 5-aminosalicylic acid (5-ASA) by colonic bacteria and the low prevailing redox potential found in this environment. The liberated 5-ASA is absorbed slowly resulting in very high local concentrations in the colon.

The conversion of olsalazine to mesalamine (5-ASA) in the colon is similar to that of sulfasalazine, which is converted into sulfapyridine and mesalamine. It is thought that the mesalamine component is therapeutically active in ulcerative colitis (A.K. Azad-Kahn et al, LANCET, 2:892-895, 1977). The usual dose of sulfasalazine for maintenance of remission in patients with ulcerative colitis is 2 grams daily, which would provide approximately 0.8 gram of mesalamine to the colon. More than 0.9 gram of mesalamine would usually be made available in the colon from 1 gram of olsalazine.

The mechanism of action of mesalamine (and sulfasalazine) is unknown, but appears to be topical rather than systemic. Mucosal production of arachidonic acid (AA) metabolites, both through the cyclooxygenase pathways (i.e., prostanoids) and through the lipoxygenase pathways (i.e., leukotrienes [LTs] and hydroxyeicosatetraenoic acids [HETEs]) is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalamine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin (PG) production in the colon.

Pharmacokinetics

The pharmacokinetics of olsalazine are similar in both healthy volunteers and in patients with ulcerative colitis. Maximum serum concentrations of olsalazine appear after approximately 1 hour and, even after a 1.0 g single dose, are low (e.g., 1.6 to 6.2 µmol/L). Olsalazine has a very short serum half-life, approximately 0.9 hour. Olsalazine is more than 99% bound to plasma proteins. It does not interfere with protein binding of warfarin. The urinary recovery of olsalazine is below 1%. Total recovery of oral 14C-labeled olsalazine in animals and humans ranges from 90 to 97%. Approximately 0.1% of an oral dose of olsalazine is metabolized in the liver to olsalazine-O-sulfate (olsalazine-S). Olsalazine-S, in contrast to olsalazine has a half-life of 7 days. Olsalazine-S accumulates to steady state within 2 to 3 weeks.

Patients on daily doses of 1.0 g olsalazine for 2 to 4 years show a stable plasma concentration of olsalazine-S (3.3 to 12.4 µmol/L). Olsalazine-S is more than 99% bound to plasma proteins. Its long half-life is mainly due to slow dissociation from the protein binding site. Less than 1% of both olsalazine and olsalazine-S appears undissociated in plasma.

5-aminosalicylic acid (5-ASA)

Serum concentrations of 5-ASA are detected after 4 to 8 hours. The peak levels of 5-ASA after an oral dose of 1.0 g olsalazine are low (i.e., 0 to 4.3 µmol/L). Of the total 5-ASA found in the urine, more than 90% is in the form of N-acetyl-5-ASA (Ac-5-ASA). Only small amounts of 5-ASA are detected.

N-acetyl-5-ASA (Ac-5-ASA), the major metabolite of 5-ASA found in plasma and urine, is acetylated (deactivated) in at least two sites, the colonic epithelium and the liver. Ac-5-ASA is found in the serum, with peak values of 1.7 to 8.7 µmol/L after a single 1.0 g dose. Approximately 20% of the total 5-ASA is recovered in the urine, where it is found almost exclusively as Ac-5-ASA. The remaining 5-ASA is partially acetylated and is excreted in the feces. From fecal dialysis, the concentration of 5-ASA in the colon following olsalazine has been calculated to be 18 to 49 mmol/L. No accumulation of 5-ASA or Ac-5-ASA in plasma has been detected. 5-ASA and Ac-5-ASA are 74 and 81%, respectively, bound to plasma proteins.

ANIMAL TOXICOLOGY

Preclinical subacute and chronic toxicity studies in rats have shown the kidney to be the major target organ of olsalazine toxicity. At an oral daily dose of 400 mg/kg or higher, olsalazine treatment produced nephritis and tubular necrosis in a 4-week study; interstitial nephritis and tubular calcinosis in a 6-month study, and renal fibrosis, mineralization, and transitional cell hyperplasia in a 1-year study.

CLINICAL STUDIES

Two controlled studies have demonstrated the efficacy of olsalazine as maintenance therapy in patients with ulcerative colitis. In the first, ulcerative colitis patients in remission were randomized to olsalazine 500 mg B.I.D. or placebo, and relapse rates for a six month period of time were compared. For the 52 patients randomized to olsalazine, 12 relapses occurred, while for the 49 placebo patients, 22 relapses occurred. This difference in relapse rates was significant (p<0.02).

In the second study, 164 ulcerative colitis patients in remission were randomized to olsalazine 500 mg B.I.D. or sulfasalazine 1 gram B.I.D., and relapse rates were compared after six months. The relapse rate for olsalazine was 19.5% while that for sulfasalazine was 12.2%, a non-significant difference.

INDICATIONS AND USAGE

Olsalazine is indicated for the maintenance of remission of ulcerative colitis in patients who are intolerant of sulfasalazine.

CONTRAINDICATIONS

Hypersensitivity to olsalazine, other salicylates, or any of the excipients.

PRECAUTIONS

General

Overall, approximately 17% of subjects receiving olsalazine in clinical studies reported diarrhea sometime during therapy. This diarrhea resulted in withdrawal of treatment in 6% of patients. This diarrhea appears to be dose related, although it may be difficult to distinguish from the underlying symptoms of the disease.

Exacerbation of the symptoms of colitis thought to have been caused by mesalamine or sulfasalazine has been noted.

Information for Patients

Patients should be instructed to take olsalazine with food. The drug should be taken in evenly divided doses. Patients should be informed that about 17% of subjects receiving olsalazine during clinical studies reported diarrhea sometime during therapy. If diarrhea occurs, patients should contact their physician.

Drug Interactions

The co-administration of salicylates and low molecular weight heparins or heparinoids may result in an increased risk of bleeding (i.e., hematomas) following neuraxial anesthesia. Salicylates should be discontinued prior to the initiation of a low molecular weight heparin or heparinoid. If this is not possible, it is recommended to monitor patients closely for bleeding.

Increased prothrombin time in patients taking concomitant warfarin has been reported.

The co-administration of olsalazine and 6-mercaptopurine or thioguanine may result in an increased risk of myelosuppression. If co-administered with 6-mercaptopurine, it is recommended to use the lowest possible doses of each drug and to monitor the patient, especially for leukopenia. In case of co-administration with thioguanine, careful monitoring of blood counts is recommended.

It is recommended not to give salicylates for six weeks after the varicella vaccine to avoid a possible increased risk of developing Reye's syndrome.

Drug/LaboratoryTest Interactions

None known.

Carcinogenesis, Mutagenesis, Impairment of Fertility

In a two year oral rat carcinogenicity study, olsalazine was tested in male and female Wistar rats at daily doses of 200, 400, and 800 mg/kg/day (approximately 10 to 40 times the human maintenance dose, based on a patient weight of 50 kg and a human dose of 1 g). Urinary bladder transitional cell carcinomas were found in three male rats (6%, p=0.022, exact trend test) receiving 40 times the human dose and were not found in untreated male controls. In the same study, urinary bladder transitional cell carcinoma and papilloma occurred in 2 untreated control female rats (2%). No such tumors were found in any of the female rats treated at doses up to 40 times the human dose.

In an eighteen month oral mouse carcinogenicity study, olsalazine was tested in male and female CD-1 mice at daily doses of 500, 1000, and 2000 mg/kg/day (approximately 25 to 100 times the human maintenance dose). Liver hemangiosarcomata were found in two male mice (4%) receiving olsalazine at 100 times the human dose, while no such tumor occurred in the other treated male mice groups or any of the treated female mice. The observed incidence of this tumor is within the 4% incidence in historical controls.

Olsalazine was not mutagenic in in vitro Ames tests, mouse lymphoma cell mutation assays, human lymphocyte chromosomal aberration tests, or the in vivo rat bone marrow cell chromosomal aberration test.

Olsalazine in a dose range of 100 to 400 mg/kg/day (approximately 5 to 20 times the human maintenance dose) did not influence the fertility of male or female rats. The oligospermia and infertility in men associated with sulfasalazine have not been reported with olsalazine.

Pregnancy

Teratogenic Effects

Pregnancy Category C

Olsalazine has been shown to produce fetal developmental toxicity as indicated by reduced fetal weights, retarded ossifications, and immaturity of the fetal visceral organs when given during organogenesis to pregnant rats in doses 5 to 20 times the human dose (100 to 400 mg/kg).

There are no adequate and well-controlled studies in pregnant women. Olsalazine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing Mothers

Small amounts of the active metabolite of olsalazine (5-ASA) may pass into breast milk. Harmful infant effects (diarrhea) have been reported when 5-ASA was used during breastfeeding. Unless the benefit of the treatment outweighs the risks, olsalazine should not be taken by breast-feeding women, or patients should be advised to discontinue breastfeeding if using olsalazine.

Oral administration of olsalazine to lactating rats in doses 5 to 20 times the human dose produced growth retardation in their pups.

Pediatric Use

Safety and effectiveness in a pediatric population have not been established.

Geriatric Use

Clinical studies of DIPENTUM did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, elderly patients should be treated with caution due to the greater frequency of decreased hepatic, renal, or cardiac function, co-existence of other disease, as well as concomitant drug therapy.

Severe Allergies and/or Asthma

Patients with severe allergies or asthma should be monitored for signs of worsening symptoms.

Renal

Patients with impaired renal function should be monitored.

Although renal abnormalities were not reported in clinical trials with olsalazine, there have been rare reports from post-marketing experience (see ADVERSE REACTIONS, Postmarketing). Therefore, the possibility of renal tubular damage due to absorbed mesalamine or its n-acetylated metabolite, as noted in the ANIMAL TOXICOLOGY section must be kept in mind, particularly for patients with pre-existing renal disease. In these patients, monitoring with urinalysis, BUN, and creatinine determinations is advised.

Hepatic

Patients with impaired hepatic function should be monitored (see ADVERSE REACTIONS, Postmarketing).

ADVERSE REACTIONS

Olsalazine has been evaluated in ulcerative colitis patients in remission, as well as those with acute disease. Both sulfasalazine-tolerant and intolerant patients have been studied in controlled clinical trials. Overall, 10.4% of patients discontinued olsalazine because of an adverse experience compared with 6.7% of placebo patients. The most commonly reported adverse reactions leading to treatment withdrawal were diarrhea or loose stools (olsalazine 5.9%; placebo 4.8%), abdominal pain, and rash or itching (slightly more than 1% of patients receiving olsalazine). Other adverse reactions to olsalazine leading to withdrawal occurred in fewer than 1% of patients (Table 1).

Table 1 Adverse Reactions Resulting In Withdrawal From Controlled Studies Total

	Olsalazine (N = 441)	Placebo (N = 208)
Diarrhea/Loose Stools	26 (5.9%)	10 (4.8 %)
Nausea	3	2
Abdominal Pain	5 (1.1%)	0
Rash/Itching	5 (1.1%)	0
Headache	3	0
Heartburn	2	0
Rectal Bleeding	1	0
Insomnia	1	0
Dizziness	1	0
Anorexia	1	0
Light Headedness	1	0
Depression	1	0
Miscellaneous	4 (0.9%)	3 (1.4%)
Total Number of Patients Withdrawn	46 (10.4%)	14 (6.7 %)

For those controlled studies, the comparative incidences of adverse reactions reported in 1% or more patients treated with olsalazine or placebo are provided in Table 2.

Table 2 Comparative Incidence (%) of Adverse Effects Reported By One Percent Or More of Ulcerative Colitis Patients Treated With Olsalazine Or Placebo in Double Blind Controlled Studies

Adverse Event	Olsalazine (N = 441) %	Placebo (N = 208) %
Gastrointestinal Disorders
Diarrhea	11.1	6.7
Abdominal Pain/Cramps	10.1	7.2
Nausea	5.0	3.9
Dyspepsia	4.0	4.3
Bloating	1.5	1.4
Vomiting	1.0	-
Stomatitis	1.0	-
Increased Blood in Stool	-	3.4
Metabolism and Nutrition Disorders
Anorexia	1.3	1.9
Nervous System Disorders
Headache	5.0	4.8
Insomnia	-	2.4
General Disorders and Administration Site Conditions
Fatigue/Drowsiness/Lethargy	1.8	2.9
Psychiatric Disorders
Depression	1.5	-
Ear and Labyrinth Disorders
Vertigo/Dizziness	1.0	-
Skin and Subcutaneous Tissue Disorders
Rash	2.3	1.4
Itching	1.3	-
Musculoskeletal and Connective Tissue Disorders
Arthralgia/Joint Pain	4.0	2.9
Infections and Infestations
Upper Respiratory Infection	1.5	-

Over 2,500 patients have been treated with olsalazine in various controlled and uncontrolled clinical studies. In these as well as in post-marketing experience, olsalazine was administered mainly to patients intolerant to sulfasalazine. There have been rare reports of the following adverse effects in patients receiving olsalazine. These were often difficult to distinguish from possible symptoms of the underlying disease or from the effects of prior and/or concomitant therapy. A causal relationship to the drug has not been demonstrated for some of these reactions.

Blood and Lymphatic System Disorders: Anemia, Eosinophilia, Hemolytic anemia, Interstitial pulmonary disease, Leukopenia, Lymphopenia, Neutropenia, Reticulocytosis, Thrombocytopenia

Cardiac Disorders: Chest pains, Heart block second degree, Myocarditis, Palpitations, Pericarditis, Peripheral edema, Shortness of breath, Tachycardia

A patient who developed thyroid disease 9 days after starting DIPENTUM was given propranolol and radioactive iodine and subsequently developed shortness of breath and nausea. The patient died 5 days later with signs and symptoms of acute diffuse myocarditis.

Ear and Labyrinth Disorders: Tinnitus

Eye Disorders: Dry eyes, Vision blurred, Watery eyes

Gastrointestinal Disorders: Abdominal pain (upper), Diarrhea with dehydration, Dry mouth, Epigastric discomfort, Flare in symptoms, Flatulence, Increased blood in stool, Pancreatitis, Rectal bleeding, Rectal discomfort

In a double-blind, placebo-controlled study, increased frequency and severity of diarrhea were reported in patients randomized to olsalazine 500 mg B.I.D. with concomitant pelvic radiation.

Rare cases of granulomatous hepatitis and nonspecific, reactive hepatitis have been reported in patients receiving olsalazine. Additionally, a patient developed mild cholestatic hepatitis during treatment with sulfasalazine and experienced the same symptoms two weeks later after the treatment was changed to olsalazine. Withdrawal of olsalazine led to complete recovery in these cases.

General Disorders and Administration Site Conditions: Fever chills, Hot flashes, Irritability, Rigors

Immune System Disorders: Bronchospasm, Erythema nodosum

Laboratory: ALT (SGPT) or AST (SGOT) elevated beyond the normal range.

Musculoskeletal and Connective Tissue Disorders: Muscle cramps

Nervous System Disorders: Insomnia, Paraesthesia, Tremors

Psychiatric Disorders: Mood swings

Renal and Urinary Disorders: Dysuria, Hematuria, Interstitial nephritis, Nephrotic syndrome, Proteinuria, Urinary frequency

Reproductive System and Breast Disorders: Impotence, Menorrhagia

Skin and Subcutaneous Tissue Disorders: Alopecia, Erythema, Photosensitivity reaction

Vascular Disorders: Hypertension, Orthostatic hypotension

Postmarketing

The following events have been identified during post-approval use of products that contain (or are metabolized to) mesalamine in clinical practice. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of seriousness, frequency of reporting, or potential causal connection to mesalamine:

Blood and Lymphatic System Disorders: Aplastic anemia, Pancytopenia

General Disorders and Administration Site Conditions: Pyrexia

Hepatobiliary Disorders: Hepatic enzyme increased, Hepatitis, Increased bilirubin

Reports of hepatotoxicity, including elevated liver function tests (SGOT/AST, SGPT/ALT, GGT, LDH, alkaline phosphatase, bilirubin), jaundice, cholestatic jaundice, cirrhosis, and possible hepatocellular damage including liver necrosis and liver failure. Some of these cases were fatal. One case of Kawasaki-like syndrome, which included hepatic function changes, was also reported.

Musculoskeletal and Connective Tissue Disorders: Myalgia

Respiratory, Thoracic and Mediastinal Disorders: Dyspnoea, Interstitial lung disease

Skin and Subcutaneous Tissue Disorders: Angioneurotic oedema

Nervous System Disorders: Paraesthesia, Peripheral neuropathy

Renal and Urinary Disorders: Interstitial nephritis

DRUG ABUSE AND DEPENDENCY

Abuse

None reported.

Dependence

Drug dependence has not been reported with chronic administration of olsalazine.

OVERDOSAGE

No overdosage has been reported in humans. The knowledge of overdosage is limited. Possible overdose symptoms include nausea, vomiting and diarrhea. It is recommended to check hematology, acid-base, electrolyte, liver and kidney status, and to provide supportive treatment. There is no specific antidote to DIPENTUM.

Maximum single oral doses of 5 g/kg in mice and rats and 2 g/kg in dogs were not lethal. Symptoms of acute toxicity were decreased motor activity and diarrhea in all species tested. In addition, vomiting was reported in dogs.

DOSAGE AND ADMINISTRATION

The usual dosage in adults for maintenance of remission is 1.0 g/day in two divided doses.

HOW SUPPLIED

Beige colored capsules, containing 250 mg olsalazine sodium imprinted with "DIPENTUM® 250 mg" on the capsule shell, available as:

Bottles of 100's              NDC 68220-160-10

Store at 20-25°C (77°F). Excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].