Monitoring of Suspected Adverse Drug Reactions in Oncology Unit ...

International Journal of Research in Pharmaceutical and Biomedical Sciences ISSN: 2229-3701
and is routinely given orally. It is mostly eliminated through the kidney and should be used with caution in
patients with compromised renal function. Hydroxyurea is used primarily in the treatment of
myeloproliferative disorders including CML, polycythemia vera and essential thrombocytosis. It has also
been used in a variety of solid tumors including carcinomas of the head and neck and those of the
genitourinary system. Mild nausea and vomiting are experienced by most patients who receive
hydroxyurea. The major dose-limiting toxicity is bone marrow depression mainly seen as leukopenia. This
is reversible when the drug is discontinued. With large amounts of the drug stomatitis and gastrointestinal
ulceration may occur.
Tamoxifen is a competitive inhibitor of estradiol binding to the estrogen receptor. It acts as a complete
antagonist in some systems and as an antagonist with partial agonist activity in other systems. By binding
to the receptor it competes with the binding of endogenous estradiol and its major therapeutic effect reflects
this antiestrogenic mechanism. It induces a change in the three-dimensional shape of the receptor inhibiting
its binding to the estrogen response element on DNA. It is administered orally. It is metabolized by the
cytochrome P 450 system to at least 6 metabolites some of which possess estrogen binding activity. These
metabolites are conjugated principally as glucuronides and excreted in the bile. The metabolites have very
long half-lives because of extensive protein binding in the plasma and efficient reuptake from the intestinal
tract. Tamoxifen is used in the treatment of metastatic breast cancer. It is used alone for palliation of
advanced breast cancer in women with estrogen receptor-positive tumors, and it is used for adjuvant
therapy in certain types of early stage disease depending on the patient’s age, receptor status of the tumor
and degree of nodal involvement. It may also have benefit as a preventive agent for breast cancer especially
in women with risk factors. Tamoxifen is very well tolerated. The most frequent side effect is acute nausea
and vomiting. This usually disappears after a few weeks and it can be reduced by taking the drug with
meals. More chronic effects include hot flushes, transient and mild thrombocytopenia and leukopenia,
vaginal bleeding, skin rashes, hypercalcemia, retinopathy and corneal opacities with high dose long-term
therapy.
Anastrozole is a selective non-steroidal aromatase inhibitor (aromatase is a P 450 enzyme that catalyzes
various steps in the conversion of androgen to estrogen). It is used for the treatment of postmenopausal
women with advanced breast cancer that has progressed during treatment with tamoxifen.
PLAN OF WORK
Study design and setting
Cross-sectional observational study with subjects recruited from the in-patient facility of the medical
oncology department of a tertiary care teaching hospital.
Study time frame
The study commenced in October, 2006 with preparatory work. The observation period was from mid-
December, 2006 till mid-March, 2007. Data analysis and report preparation was done in the remaining
period till mid-April, 2007.
For the individual patient, the observation would be at a single time point only.
Methods
Initially, patients receiving cytotoxic anticancer drugs as part of their therapeutic regimens were
screened from out-patient or in-patient departments by the attending clinicians. The screened patients were
interviewed (i.e. a thorough clinical history taken), clinically examined as necessary, with the help of the
attending clinicians and medical and laboratory records reviewed for those admitted.
For capturing the data, rather than designing a Case Report Form de novo, the Suspected ADR
Reporting Form of the National Pharmacovigilance Programme itself was used since this provides a
standardized format. A copy has been provided in Annex 1. The form allows data to be organized in four
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