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Indian Journal of Dermatology, Venereology and Leprology
Medknow Publications on behalf of The Indian Association of Dermatologists, Venereologists and Leprologists (IADVL)
ISSN: 0378-6323 EISSN: 0973-3922
Vol. 70, Num. 4, 2004, pp. 247-248
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Indian Journal of Dermatology, Venereology, Leprology, Vol. 70, No. 4, July-August, 2004, pp. 247-248
Letter To Editor
Response by Dr. Rao and Dr. Laxmi
Rao PNarasimha, Laxmi TSS
Dept. of Dermatology, Osmania Hospital & Osmania Medical College, Hyderabad
Correspondence Address:B-48, Income Tax Colony, Mehdipatnam, Hyderabad
- 500 028 dermarao@hotmail.com
Code Number: dv04084
Sir,
We thank Dr Navin Modi for his comments and for the interest shown in
our article. In response to the points raised in his letter, I would
like to make the following remarks.
- Duration of infusion time of cyclophosphamide pulse:
Cyclophosphamide is a pro-drug that is converted by hepatic microsomal
enzymes into 4-hydroxy cyclophosphamide. The concentration of 4-hydroxycyclophosphamide
is 5 to10% of the concentration of cyclophosphamide at peak steady
state.[1] The
half life of 4-hydroxycyclophosphamide is about the same as that of cyclophosphamide
ranging between 3-10 hours.[2] Cyclophosphamide
is supplied in 50 mg tablets and vials containing powder for injection.
Solution for injection is prepared by adding 5 ml. of sterile water. Unlike
mechlorethamine, solution remains stable for 3 hours.[3] By
above reasons it is all right if it is administered over 2 hours in an
intravenous infusion as its pharmacological activity is not affected. Moreover,
cyclophosphamide is added to the same solution wherein dexamethasone is
present and it is advisable to administer it over 2-4 hours to avoid the
adverse effects associated with pulse steroid therapy.[4
- Prevention of cyclophosphamide induced sterile hemorrhagic cystitis
The rationale behind the additional infusion of 500ml of 5% dextrose
on the day of intravenous cyclophosphamide is to wash out any retained
drug in the urinary tract to prevent urinary complications of cyclophosphamide.[5] We
have made this a part of the protocol so that adequate hydration become
a fixed routine on the day of administration of cyclophosphamide. We
chose 5% dextrose to the normal saline to avoid the sodium load.
This was well accepted by the patients and none of our patients had any
complications associated with such an administration.. Adequate oral
supplementation of fluids definitely will suffice. However, such instruction
which cannot be incorporated in protocol are frequently neglected / over
looked.
The use of MESNA in these patients is an accepted practice. However studies [6],[7] have
shown that subclinical renal toxicity has been observed in children receiving
ifosfamide, which is an oxazophosphorine like cyclophosphamide, despite
MESNA administration and that administration of MESNA does not eliminate
the need for adequate hydration and careful observation of the patient.
- The early morning administration of steroids to avoid HPA axis suppression
is only relevant when short or intermediate acting corticosteroids are
used for therapy. In pulse therapy for pemphigus, we are administering
high dose of dexamethasone which is a long acting corticosteroid, (action
for 24 to 36 hours). Hence, irrespective of the time of administration,
the drug is in circulation for the whole day. More importantly it is administered
only for 3 days in a month. Adrenal suppression occurs only when corticosteroids
are administered for more than 2 weeks[9] which
is not the case in pulse therapy for pemphigus.
REFERENCES
1. | Teicher BA. Antitumor alkylating agents: Pharmacology of cancer chemotherapy. In: Devita VT, Hellman S, Rosenberg SA, editors. Cancer principles and practice of oncology, 5th Ed, New York: Lippincott-Raven; 1997. p. 405-18. Back to cited text no. 1 |
2. | Cyclophosphamide in cancer chemotherapy, Book section of www.pubmed.com Back to cited text no. 2 |
3. | Satoskar RS, Bhandarkar SD, Ainapure SS. Pharmacology and pharmacotherapeutics. 17th Ed. Mumbai: Popular Prakashan; 2001. Back to cited text no. 3 |
4. | Werth VP, Lazarus GS. Systemic glucocorticoids. In: Freedberg IM, Eisen AZ, Wolff K, Austen KF, Goldsmith LA, Katz SI, Fitzpatrick TB, editors. Fitzpatrick's Dermatology in general medicine. 5th Ed, New York: McGraw Hill; 1999. p. 2783-9. Back to cited text no. 4 |
5. | Narasimha Rao P, Lakshmi TS. Pulse therapy and its modifications in pemphigus: A six-year study. Indian J Dermatol Venereol Leprol 2003;69:329-33. Back to cited text no. 5 |
6. | Pratt CB, Douglass EC, Etcubanas E, Goren MP, Green AA, Hayes FA, et al. Clinical studies of ifosfamide/MESNA at St. Jude Children's Research Hospital, 1983-1988 Semin Oncol 1989;16:51-5. Back to cited text no. 6 |
7. | Pratt CB, Horowitz ME, Meyer WH, Etcubanas E, Thompson EI, Douglass EC, et al. Phase II trial of ifosfamide in children with malignant solid tumors. Cancer Treat Rep 1987;71:131-5. Back to cited text no. 7 |
8. | Choruses GP, Margioris AN. Adrenocorticosteroids and adrenocortical antagonists. In: Katzung BG, editor. Basic clinical pharmacology, 8th Ed, New York: Lange medical books; 2001. p. 660-78. Back to cited text no. 8 |
Copyright 2004 - Indian Journal of Dermatology, Venereology, Leprology
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