Radiation Cystitis Medication

Updated: Mar 15, 2021
  • Author: Nicolas A Muruve, MD, FACS, FRCSC; Chief Editor: Edward David Kim, MD, FACS  more...
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Medication Summary

Pharmacologic therapy for radiation cystitis is primarily aimed at relief of symptoms. Symptomatic frequency and urgency are best treated with anticholinergic agents. Once all other causes of dysuria have been ruled out, phenazopyridine can be used to provide symptomatic relief. If the symptoms of radiation cystitis are not severe but are significant enough for a patient to seek help, pentosan polysulfate sodium (Elmiron), with or without pentoxifylline for pain, is a reasonable first step. For severe hematuria, instillation of a variety of agents into the bladder may be tried.

Formalin, a 37% solution of formaldehyde and water compounded at the pharmacy, is a tissue fixative. Adult dosing depends on the method of administration. Dosing for local therapy consists of 5% formalin pledgets placed endoscopically on bleeding points for 15 minutes and then removed. For bladder irrigation, a 1-10% solution (4% preferred) is used; manually fill the bladder to capacity under gravity (catheter < 15cm above the symphysis pubis); contact time ranges from 14 minutes for a 10% solution to 23 minutes for a 5% solution. This is a painful procedure and requires a general anesthetic. The response rate is 52-89%, and the recurrence rate is 20-25%.

Alum, which is also compounded at the pharmacy, causes protein precipitation in the interstitial spaces and cell membranes, causing contraction of the extracellular matrix and tamponade of bleeding vessels. Exposed capillary epithelium is also sclerosed. In adults, a 1% solution is prepared by mixing 50 g of potassium aluminum sulfate in 5L of distilled water; it is run intravesically at a rate of 3-5 mL/min and increased to a maximum of 10 mL/min if returns are not clear; it is continued for 6 hours after bleeding stops. Alum has a response rate of 50-80%, and the recurrence rate is 10%.


Analgesics, Urinary

Class Summary

Urinary analgesics provide relief of bladder pain due to interstitial cystitis.

Phenazopyridine (Pyridium, ReAzo, Baridium)

Phenazopyridine is an azo dye that has local anesthetic or analgesic action. It acts directly on urinary tract mucosa when excreted.

Pentosan polysulfate sodium (Elmiron)

Pentosan polysulfate sodium protects transitional epithelium by restoring the bladder glycosaminoglycan layer. Adult dosing is 100mg orally 3 times daily until symptoms resolve, for a minimum of 4 weeks. The response rate in radiation cystitis is 71-100%, and the recurrence rate is 23%. [29] Sodium pentosan polysulfate is a pregnancy category B drug.



Class Summary

Hemostatic agents are potent inhibitors of fibrinolysis and can reverse states that are associated with excessive fibrinolysis.

Aminocaproic acid (Amicar)

Aminocaproic acid is an antifibrinolytic agent that inhibits plasminogen activation, thus decreasing plasmin. Adult dosing is 200mg of aminocaproic acid in 1L of isotonic sodium chloride solution. It is run intravesically according to the severity of bleeding and continued for 24 hours after bleeding stops.

Aminocaproic acid has a response rate of 91%, and recurrences have not been reported. This agent is a pregnancy category C drug.


Estrogen Derivatives

Class Summary

Estrogen derivatives have been used to correct prolonged bleeding time.

Conjugated estrogens (Premarin)

The mechanism of action of conjugated estrogens in radiation cystitis is unknown. In patients with renal failure, estrogen has been reported to correct prolonged bleeding time. However, in radiation cystitis complications, bleeding time is usually normal. Adult dosing is 5mg/day orally for 4-7 days.

Conjugated estrogens have a response rate of 100%, and the recurrence rate is 20% (1 report of 5 patients only). Conjugated estrogen is a pregnancy category X drug.


Hemorheologic Agents

Class Summary

Hemorheologic agents enhance blood flow by reducing components responsible for blood viscosity.

Pentoxifylline (Trental)

Pentoxifylline has been shown to relieve pain due to radiation fibrosis. Pentoxifylline and its metabolites improve the flow properties of blood by decreasing its viscosity. This increases blood flow to the affected microcirculation and enhances tissue oxygenation. The precise mode of action of pentoxifylline and the sequence of events leading to clinical improvement remain undefined. Adult dosing is 400mg orally 3 times daily for 6 weeks. Pentoxifylline is a pregnancy category C drug.