, skin breakdown, hepatic and renal failure, hypotension, bradycardia, and cardiovascular collapse. The minimum amount of benzyl alcohol at which toxicity may occur is not known. Premature and low-birth weight infants, as well as patients receiving high dosages, may be more likely to develop toxicity. Practitioners administering this and other medications containing benzyl alcohol should consider the combined daily metabolic load of benzyl alcohol from all sources [See Warnings and Precautions (5.3)].
8.5 Geriatric UseClinical studies of mesna did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. The ratio of ifosfamide to mesna should remain unchanged.
8.6 Use in Patients with Renal ImpairmentNo clinical studies were conducted to eva luate the effect of renal impairment on the pharmacokinetics of mesna.
8.7 Use in Patients with Hepatic ImpairmentNo clinical studies were conducted to eva luate the effect of hepatic impairment on the pharmacokinetics of mesna.
10. OVERDOSAGE
There is no known antidote for mesna.
In a clinical trial, 11 patients received intravenous mesna 10 mg/kg to 66 mg/kg per day for 3 to 5 days. Patients also received ifosfamide or cyclophosphamide. Adverse reactions included nausea, vomiting, diarrhea and fever. An increased rate of these adverse reactions has also been found in oxazaphosphorine-treated patients receiving ≥80 mg mesna per kg per day intravenously compared with patients receiving lower doses or hydration treatment only.
Postmarketing, administration of 4.5 g to 6.9 g of mesna resulted in hypersensitivity reactions including mild hypotension, shortness of breath, asthma exacerbation, rash, and flushing.
11. DESCRIPTION
Mesna is a detoxifying agent to inhibit the hemorrhagic cystitis induced by ifosfamide. The active ingredient, mesna, is a synthetic sulfhydryl compound designated as sodium-2-mercaptoethane sulfonate with a molecular formula of C2H5NaO3S2 and a molecular weight of 164.18. Its structural formula is as follows:
HS–CH2–CH2SO3–Na+
Mesna injection is a sterile, nonpyrogenic, aqueous solution of clear and colorless to light pink appearance in clear glass multidose vials for intravenous administration. Mesna injection contains 100 mg/mL mesna, 0.25 mg/mL edetate disodium and sodium hydroxide for pH adjustment. Mesna injection multidose vials also contain 10.4 mg/mL of benzyl alcohol as a preservative. The solution has a pH range of 6.5 to 7.3.
12. CLINICAL PHARMACOLOGY
12.1 Mechanism of ActionMesna reacts chemically with the urotoxic ifosfamide metabolites, acrolein and 4-hydroxy-ifosfamide, resulting in their detoxification. The first step in the detoxification process is the binding of mesna to 4-hydroxy-ifosfamide forming a non-urotoxic 4-sulfoethylthioifosfamide. Mesna also binds to the double bonds of acrolein and to other urotoxic metabolites and inhibits their effects on the bladder.
12.3 PharmacokineticsAbsorption
Bioavailability averaged 58% (range 45 to 71%) for free mesna and 89% (range 74 to 104%) for total mesna based on plasma AUC data from 8 healthy volunteers who received 1200 mg intravenous doses.
Distribution
Mean apparent v |
