This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamin, Subject name: Pharmacology
[{'content': 'Dose of centchroman is - \nSelect and explain. \nA. 30 mg, B. 60 mg, C. 120 mg, D. 240 mg', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., 30 mg Cetchroman (Saheli)o Ormeloxifene, research product of Central Drug Research Institute, Lucknow, India.o It is a potent non - steroidal compound with potent anti - estrogenic and weak estrogenic properties. It is taken orally (30 mg) twice a wreek for first three months then once a wreek.o It works primarily by preventing implantation of fertilized ovum. It does not inhibit ovulation,o It is avoided in PCOD, writh liver and kidney diseases and in tuberculosis. There may be a tendency of oligomenorrhoea.o The failure rate is 1 - 4/100 woman years of use. Failure rate is less with increased doses. It is devoid of any significant adverse metabolic effect.o This may also be used as a emergency contraceptive.", 'role': 'assistant'}]