Uses of Lexel: - Breast cancer - Infertility due to anovulation Breast cancer Premenopausal women and children; hypersensitivity.

Hormonal Chemotherapy

Letrozole is a nonsteroidal aromatase inhibitor. It inhibits the conversion of androgen to estrogen. In contrast to ovariectomy, treatment with letrozole does not lead to an increase in serum FSH. Letrozole selectively inhibits gonadal steroidogenesis but has no significant effect on adrenal mineralocorticoid or glucocorticoid synthesis. Letrozole inhibits the aromatase enzyme by competitively binding to the heme of the cytochrome P450 subunit of the enzyme, resulting in a reduction of estrogen biosynthesis in all tissues. Treatment of women with letrozole significantly lowers serum estrone, estradiol and estrone sulfate and has not been shown to significantly affect the adrenal corticosteroid synthesis, ldosterone synthesis, or synthesis of thyroid hormones.

How to use Letrozole: Take this medicine in the dose and duration as advised by your doctor. Swallow it as a whole. Do not chew, crush or break it. Letrozole may be taken with or without food, but it is better to take it at a fixed time. Administration: May be taken with or without food. Adult Dose: Oral Advanced or locally advanced breast cancer ; Adjuvant therapy for postmenopausal women with hormone receptor positive early breast cancer Adult: 2.5 mg once daily. Hepatic impairment: Reduce dose by 50% in patients with cirrhosis and severe hepatic impairment; recommended dose: 2.5 mg on alternate days.

Plasma levels reduced by tamoxifen.

Premenopausal women and children; hypersensitivity.

Common - Fatigue - Hypercholesterolemia (high cholesterol) - Increased sweating Hot flushes, arthralgia, nausea, vomiting, fatigue, dizziness, headache, dyspepsia, constipation, diarrhoea, anorexia, alopoecia, increased sweating, rash, peripheral oedema, osteoporosis, musculoskeletal pain, vaginal irritation. Potentially Fatal: Thromboembolic events.

Pregnancy Category D. It is not known if Letrozole is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Letrozole is administered to a nursing woman.

Precaution: Severe renal impairment; severe hepatic impairment; osteoporosis. Caution when driving or operating machinery. Lactation: not known if excreted in breast milk (for post-menopausal women)

There is no clinical experience of overdosage. There is no specific antidote to letrozole. Since letrozole is not highly protein-bound, dialysis may be helpful. Emesis may be induced if the patient is alert. In general, supportive care and frequent monitoring of vital signs is appropriate.

Keep below 30°C temperature, away from light & moisture. Keep out of the reach of children.

Hormonal Chemotherapy

Letrozole competitively binds to the heme group of aromatase, a cytochrome P450 enzyme which catalyzes conversion of androgen to oestrogen, leading to inhibition of the enzyme and a significant reduction in plasma oestrogen levels.

Oral administration of letrozole in pregnant rats resulted in teratogenicity and maternal toxicity at 0.03 mg/kg. Embryotoxicity and foetotoxicity were seen at doses >0.003 mg/kg and there was an increase in the incidence of foetal malformation among the animals treated. However, there are no adequate and well-controlled studies of letrozole in pregnant women and its use in these patients is not recommended. It is not known whether letrozole is excreted in human milk. Because many drugs are excreted in human milk, letrozole should not be administered to a nursing woman.