mesna

Action

Reacts in kidney with urotoxic ifosfamide metabolites (acrolein and 4-hydroxy-ifosfamide), resulting in their detoxification. Also binds to double bonds of acrolein and to other urotoxic metabolites.

Availability

Injection: 100 mg/ml in 10-ml vials

Tablets (coated): 400 mg

Indications and dosages

➣ To prevent hemorrhagic cystitis in patients receiving ifosfamide

Adults: Combination I.V. and P.O. regimen-Single I.V. bolus dose of mesna at 20% of ifosfamide dosage, given at same time as ifosfamide, followed by two doses of mesna tablets P.O. at 40% of ifosfamide dosage given 2 and 6 hours after ifosfamide dose. I.V. regimen-I.V. bolus of mesna at 20% of ifosfamide dosage given at same time as ifosfamide, repeated 4 and 8 hours after each ifosfamide dose.

Dosage adjustment

• Children

Contraindications

• Hypersensitivity to drug or other thiol compounds

Precautions

Use cautiously in:

• autoimmune disorders

• pregnant or breastfeeding patients.

Administration

• Dilute with dextrose 5% in water, dextrose 5% in normal saline solution, dextrose 5% in 0.2% sodium chloride solution, dextrose 5% in 0.33% sodium chloride solution, dextrose 5% in 0.45% sodium chloride solution, normal saline solution, or lactated Ringer's solution for injection.

• Give I.V. bolus over at least 1 minute with ifosfamide dose and at prescribed intervals after ifosfamide doses.

☞ Don't use multidose vial (contains benzyl alcohol) in neonates or infants. In older children, use with caution.

• If patient vomits within 2 hours of oral mesna dose, repeat oral dose or switch to I.V. route.

Adverse reactions

CNS: fatigue, malaise, irritability, headache, dizziness, drowsiness, hyperesthesia, rigors

CV: hypertension, hypotension, ST-segment elevation, tachycardia

EENT: conjunctivitis, pharyngitis, rhinitis

GI: nausea, vomiting, diarrhea, constipation, anorexia, flatulence

Hematologic: hematuria

Musculoskeletal: back pain, joint pain, myalgia

Respiratory: coughing, tachypnea, bronchospasm

Skin: flushing, rash

Other: arm or leg pain, injection site reactions, fever, flulike symptoms, allergic reactions

Interactions

Drug-diagnostic tests. Hepatic enzymes: increased levels

Urinary erythrocytes: false-positive or false-negative results

Urine tests using Ames Multistix: false-positive for ketonuria

Patient monitoring

• Monitor nutritional and hydration status.

• Monitor vital signs and ECG. Watch closely for blood pressure changes and tachycardia.

• Assess body temperature. Stay alert for fever, flulike symptoms, and EENT infections.

• Monitor respiratory status carefully. Watch closely for cough, bronchospasm, and tachypnea.

Patient teaching

• Inform patient that drug may cause significant adverse effects. Reassure him that he will be monitored closely.

• Encourage patient to request analgesics or other pain-relief measures for headache, back or joint pain, hyperesthesia, or muscle ache.

☞ Advise patient to immediately report breathing difficulties and allergic symptoms.

• Inform patient about drug's adverse CNS effects. Explain safety measures used to prevent injury.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the tests mentioned above.