Mesna
Mesna (Mesnex)
Mesna
( MEZ-nah)
Pregnancy Category: B Mesnex Uromitexan (Rx)

Classification: Antidote for use with ifosfamide

Action/Kinetics: Ifosfamide is metabolized to products that cause hemorrhagic cystitis. In the kidney, mesna reacts chemically with these ifosfamide metabolites to cause their detoxification. Following IV use, mesna is rapidly oxidized to mesna disulfide (dimesna), which is eliminated by the kidneys. t 1/2 in blood, mesna: 0.36 hr; dimesna: 1.17 hr. t 1/2, terminal: 7 hr.

Uses: Prophylactically to reduce the incidence of hemorrhagic cystitis caused by ifosfamide. Investigational: Reduce incidence of hemorrhagic cystitis caused by cyclophosphamide.

Contraindications: Hypersensitivity to thiol compounds. Lactation.

Special Concerns: This product contains benzyl alcohol, which may cause a fatal "gasping syndrome" in infants.

Side Effects: Since mesna is used with ifosfamide and other antineoplastic agents, it is difficult to identify those side effects due to mesna. The following symptoms are believed possible. GI: Bad taste in mouth (100%), soft stools, diarrhea, limb pain, headache, fatigue, nausea, hypotension, and allergy.

Laboratory Test Alterations: False + test for urinary ketones.

How Supplied: Injection: 100 mg/mL

Dosage
?IV Bolus Prophylaxis of ifosfamide-induced hemorrhagic cystitis.
Dosage of mesna equal to 20% of the ifosfamide dose given at the time of ifosfamide and at 4 and 8 hr after each dose of ifosfamide. Thus, the total daily dose of mesna is 60% of the ifosfamide dose (e.g., an ifosfamide dose of 1.2 g/m ² would mean doses of mesna would be 240 mg/m ² at the time the ifosfamide dose was given, 240 mg/m ² after 4 hr, and 240 mg/m ² after 8 hr). This dosage should be given on each day that ifosfamide is administered.