Olsalazine

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.

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.

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.

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:

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:

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 olsalazine 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