Abstract
Background: Cancer is a set of diseases that include the unchecked proliferation and spread of abnormal body cell types. The primary treatment modalities are surgery, radiation, chemotherapy, immunotherapy, and hormones. As it describes the scope, nature, and causes of drug exposures, drug use research is a key and vital component of pharmacoepidemiology.

Aim and Objectives: To conduct a study in a tertiary care teaching hospital to examine drug usage patterns among indoor radiotherapy patients.

Materials and Methods: A prospective, cross-sectional, observational study was conducted in indoor patients of the radiotherapy department of a tertiary care teaching hospital. Six hundred patients of different types of cancers were involved in the study. At the end of data collection, the data were entered and analyzed with Microsoft Excel 2019. Descriptive statistics were used to analyze the results.

Results: Buccal mucosa, tongue, and breast cancers had the highest admission rate with 24.17%, 13.33%, and 12.83%, respectively. The average number of drugs per encounter was 13.58 with a range of 5–17. The most frequently used anticancer drugs were cisplatin, carboplatin, paclitaxel, 5-fluorouracil, cyclophosphamide, and Adriamycin. Out of 32 drugs, 30 drugs were prescribed from the World Health Organization Model List of Essential Medicines, 2021, and National List of Essential Medicines, 2022, and 8 drugs were prescribed by brand name.

Conclusion: Compared to other systems such as the pulmonary, breast, genitourinary, and gastrointestinal tract, oral malignancies were more common. The most frequently used anticancer drugs were cisplatin, carboplatin, paclitaxel, 5-fluorouracil, cyclophosphamide, and Adriamycin. Prescribing drugs were mainly from Essential Drug List with generic names.

Key words: Cancer; Carboplatin; Cisplatin; Chemotherapy; Rational Use of Medicines