Mesalazin Orion (Mesalazine)

• Mesalazin Orion is a 5‑ASA drug that acts locally on the inflamed intestinal mucosa in ulcerative colitis and related disorders.
• Ulcerative colitis: induces remission and reduces relapse rates in patients with active disease.
• Proctitis: delivers targeted anti‑inflammatory effect to the rectal mucosa.
• Pouchitis: helps control inflammation in ileal pouch‑anal anastomosis.
• Inflammatory bowel disease (IBD) overall: provides local therapy to manage mild to moderate disease activity.

• Mesalazine exerts its anti‑inflammatory effect by inhibiting cyclooxygenase and lipoxygenase pathways within the intestinal mucosa, leading to reduced synthesis of prostaglandins and leukotrienes. The resulting decrease in these mediators limits neutrophil activation and cytokine release, thereby attenuating mucosal inflammation characteristic of ulcerative colitis and related disorders. Additionally, mesalazine may modulate NF‑κB signaling and promote antioxidant activity, further contributing to mucosal healing.

Mesalazin Orion may be associated with a range of adverse reactions, which are generally classified by frequency and severity.

Common Side Effects

• Abdominal pain or cramping
• Diarrhea or loose stools
• Nausea or mild vomiting
• Headache
• Flatulence or bloating
• Rectal irritation or burning sensation

Serious or Rare Side Effects

• Severe allergic reaction (anaphylaxis, rash, swelling)
• Blood in stool or marked gastrointestinal bleeding
• Significant elevation of liver enzymes or hepatitis
• Acute pancreatitis

Before initiating therapy, clinicians should evaluate patient-specific factors and monitor for potential complications.

• Renal function: assess baseline creatinine and monitor periodically, as mesalazine can affect kidney function.
• Hepatic function: check liver enzymes before treatment and during therapy.
• Hematologic status: perform complete blood count to detect rare leukopenia or thrombocytopenia.
• Pregnancy and lactation: safety not fully established; weigh benefits against potential risks.
• Concomitant medications: review for possible interactions, especially with anticoagulants and immunosuppressants.
• Store at room temperature: keep in the original container, protect from moisture and light.

Mesalazin Orion can interact with several drug classes; some combinations require avoidance while others need close monitoring.

Major Interactions (Avoid)

• Anticoagulants (e.g., warfarin): increased risk of bleeding.
• Azathioprine or 6‑mercaptopurine: heightened risk of bone‑marrow suppression.

Moderate Interactions (Monitor Closely)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): may exacerbate renal toxicity.
• Oral contraceptives: possible reduction in contraceptive efficacy.
• Allopurinol: may increase mesalazine plasma concentrations.