MESNA
| MESNA (mes'na) Mesnex Classifications: chemoprotectant; detoxifying agent; Therapeutic: detoxifying agent Pregnancy Category: B |
Availability
100 mg/mL injection
400 mg tablet
Action
Detoxifying agent used to inhibit the hemorrhagic cystitis induced by ifosfamide.
Therapeutic Effect
Reacts chemically with urotoxic ifosfamide metabolites, resulting in their detoxification, and thus significantly decreases the incidence of hematuria.
Uses
Prophylaxis for ifosfamide-induced hemorrhagic cystitis. Not effective in preventing hematuria due to other pathologic conditions such as thrombocytopenia.
Unlabeled Uses
Reduces the incidence of cyclophosphamide-induced hemorrhagic cystitis.
Contraindications
Hypersensitivity to mesna or other thiol compounds; neonates; lactation.
Cautious Use
Autoimmune diseases; infants (injection) pregnancy (category B).
Route & Dosage
| Ifosfamide-Induced Hemorrhagic Cystitis Adult: IV Dose = 20% of ifosfamide dose and is given at time of ifosfamide administration and 4 and 8 h after ifosfamide dose PO 40% of ifosfamide dose 2 and 6 h after each ifofsamide dose |
Administration
- Note: To be effective, mesna must be administered with each dose of ifosfamide.
| Intravenous PREPARE: Direct: Add 4 mL of D5W, NS, or RL for each 100 mg of mesna to yield 20 mg/mL. ADMINISTER: Direct: Give a single dose by direct IV over 60 sec. INCOMPATIBILITIES Solution/additive: Carboplatin, cisplatin, ifosfamide with epirubicin. Y-site: Amphotericin B cholesteryl complex.
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- Refrigerate diluted solutions or use within 6 h of mixing even though diluted solutions are chemically and physically stable for 24 h at 25° C (77° F).
- Store unopened ampul at 15°–30° C (59°–86° F) unless otherwise specified.
Adverse Effects (≥1%)
GI: Bad taste in mouth, soft stools, nausea, vomiting.Diagnostic Test Interference
May produce a false-positive result in test for urinary ketones.
Interactions
Drug: May decrease the effect of warfarin.Pharmacokinetics
Bioavailability: 45%–79% Metabolism: Rapidly oxidized in liver to active metabolite dimesna; dimesna is further metabolized in kidney. Elimination: 65% in urine within 24 h. Half-Life: Mesna 0.36 h, dimesna 1.17 h.Nursing Implications
Assessment & Drug Effects
- Monitor urine for hematuria.
- Be aware that a false-positive test for urinary ketones may arise in patients treated with mesna. In this test, a red-violet color develops that, with the addition of glacial acetic acid, will turn to violet.
- About 6% of patients treated with mesna along with ifosfamide still develop hematuria.
Patient & Family Education
- Mesna prevents ifosfamide-induced hemorrhagic cystitis; it will not prevent or alleviate other adverse reactions or toxicities associated with ifosfamide therapy.
- Report any unusual or allergic reactions to physician.
- Check with physician before using any new prescription or OTC medicine.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug