Home FDA labels ff81176c-e23e-4cb4-b3f8-e2b08b51cf46 FDA label ff81176c-e23e-4cb4-b3f8-e2b08b51cf46 openFDA label record# This page contains supplementary openFDA label data. For the canonical label presentation, use the corresponding DailyMed Structured Product Label.
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SPL set ID eb9ef121-71c7-436f-85d0-aa3649852915
SPL ID ff81176c-e23e-4cb4-b3f8-e2b08b51cf46
Version 12
Effective date 2017-07-31
Source export date 2026-10-12
Source partition 5
Source file https://download.open.fda.gov/drug/label/drug-label-0005-of-0014.json.zip
Source object key raw/openfda/drug-label/2026-10-12/13cbfcd236c665f0ee69e2d9141331148dcdff45d1679c92f029cfba27dd74a2/drug-label-0005-of-0014.json.zip
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Import run 20261013T011858Z
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warnings and cautions 5 WARNINGS AND PRECAUTIONS Decreases in bone mineral density may occur. Consider bone mineral density monitoring ( 5.1 ) Increases in total cholesterol may occur. Consider cholesterol monitoring. ( 5.2 ) Fatigue, dizziness and somnolence may occur. Exercise caution when operating machinery ( 5.4 ) 5.1 Bone Effects Use of letrozole tablets, USP may cause decreases in bone mineral density (BMD). Consideration should be given to monitoring BMD. Results of a substudy to evaluate safety in the adjuvant setting comparing the effect on lumbar spine (L2-L4) bone mineral density (BMD) of adjuvant treatment with letrozole to that with tamoxifen showed at 24 months a median decrease in lumbar spine BMD of 4.1% in the letrozole arm compared to a median increase of 0.3% in the tamoxifen arm (difference = 4.4%) ( P <0.0001) [see Adverse Reactions ( 6.1 )]. Updated results from the BMD sub-study in the extended adjuvant setting demonstrated that at 2 years patients receiving letrozole had a median decrease from baseline of 3.8% in hip BMD compared to a median decrease of 2.0% in the placebo group. The changes from baseline in lumbar spine BMD in letrozole and placebo treated groups were not significantly different [see Adverse Reactions ( 6.2 )]. In the adjuvant trial the incidence of bone fractures at any time after randomization was 13.8% for letrozole and 10.5% for tamoxifen. The incidence of osteoporosis was 5.1% for letrozole and 2.7% for tamoxifen [see Adverse Reactions ( 6.1 )]. In the extended adjuvant trial the incidence of bone fractures at any time after randomization was 13.3% for letrozole and 7.8% for placebo. The incidence of new osteoporosis was 14.5% for letrozole and 7.8% for placebo [see Adverse Reactions ( 6.3 )]. 5.2 Cholesterol Consideration should be given to monitoring serum cholesterol. In the adjuvant trial hypercholesterolemia was reported in 52.3% of letrozole patients and 28.6% of tamoxifen patients. CTC grade 3-4 hypercholesterolemia was reported in 0.4% of letrozole patients and 0.1% of tamoxifen patients. Also in the adjuvant setting, an increase of ≥1.5 X ULN in total cholesterol (generally non-fasting) was observed in patients on monotherapy who had baseline total serum cholesterol within the normal range (i.e., <=1.5 X ULN) in 151/1843 (8.2%) on letrozole vs 57/1840 (3.2%). Lipid lowering medications were required for 25% of patients on letrozole and 16% on tamoxifen [see Adverse Reactions ( 6.1 )]. 5.3 Hepatic Impairment Subjects with cirrhosis and severe hepatic impairment who were dosed with 2.5 mg of letrozole tablets, USP experienced approximately twice the exposure to letrozole tablets, USP as healthy volunteers with normal liver function. Therefore, a dose reduction is recommended for this patient population. The effect of hepatic impairment on letrozole tablets, USP exposure in cancer patients with elevated bilirubin levels has not been determined. [see Dosage and Administration ( 2.5 )]. 5.4 Fatigue and Dizziness Because fatigue, dizziness, and somnolence have been reported with the use of letrozole tablets, USP, caution is advised when driving or using machinery until it is known how the patient reacts to letrozole tablets, USP use. 5.5 Laboratory Test Abnormalities No dose-related effect of letrozole tablets, USP on any hematologic or clinical chemistry parameter was evident. Moderate decreases in lymphocyte counts, of uncertain clinical significance, were observed in some patients receiving letrozole tablets USP, 2.5 mg. This depression was transient in about half of those affected. Two patients on letrozole tablets, USP developed thrombocytopenia; relationship to the study drug was unclear. Patient withdrawal due to laboratory abnormalities, whether related to study treatment or not, was infrequent.
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adverse reactions table <table cellspacing="0" cellpadding="0"> <caption>Table 4: Percentage (%) of Patients with Adverse Reactions</caption> <col width="1px"/> <col width="1px"/> <col width="1px"/> <col width="1px"/> <col width="1px"/> <tbody> <tr> <td valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph> <content styleCode="bold">Adverse Reaction</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph> <content styleCode="bold">Pooled Letrozole tablets, USP</content> <content styleCode="bold">2.5 mg</content> <content styleCode="bold">(N=359)</content> <content styleCode="bold">%</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph> <content styleCode="bold">Pooled Letrozole tablets, USP</content> <content styleCode="bold">0.5 mg</content> <content styleCode="bold">(N=380)</content> <content styleCode="bold">%</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph> <content styleCode="bold">megestrol acetate</content> <content styleCode="bold">160 mg</content> <content styleCode="bold">(N=189)</content> <content styleCode="bold">%</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph> <content styleCode="bold">aminoglutethimide</content> <content styleCode="bold">500 mg</content> <content styleCode="bold">(N=178)</content> <content styleCode="bold">%</content> </paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> <content styleCode="bold">Body as a Whole</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "/> <td> </td> <td styleCode=" Lrule Rrule "> </td> <td styleCode=" Lrule Rrule "> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Fatigue</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>8</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>11</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Chest Pain</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Peripheral Edema<sup>1</sup> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>8</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Asthenia</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>4</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>4</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Weight Increase</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>2</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>2</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>9</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> <content styleCode="bold">Cardiovascular</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "/> <td> </td> <td styleCode=" Lrule Rrule "> </td> <td styleCode=" Lrule Rrule "> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Hypertension</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> <content styleCode="bold">Digestive System</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "/> <td> </td> <td styleCode=" Lrule Rrule "/> <td> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Nausea</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>13</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>15</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>9</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>14</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Vomiting</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>9</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Constipation</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>9</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Diarrhea</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>4</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Pain-Abdominal</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>9</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>8</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Anorexia</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Dyspepsia</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>4</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> <content styleCode="bold">Infections/Infestations</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "/> <td> </td> <td styleCode=" Lrule Rrule "/> <td/> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Viral Infection</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> <content styleCode="bold">Lab Abnormality</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "/> <td/> <td/> <td/> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Hypercholesterolemia</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>0</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> <content styleCode="bold">Musculoskeletal System</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "/> <td/> <td/> <td/> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Musculoskeletal<sup>2</sup> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>21</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>22</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>30</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>14</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Arthralgia</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>8</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>8</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>8</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> <content styleCode="bold">Nervous System</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "/> <td/> <td/> <td/> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Headache</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>9</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>12</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>9</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Somnolence</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>2</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>2</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>9</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Dizziness</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> <content styleCode="bold">Respiratory System</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "/> <td/> <td/> <td/> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Dyspnea</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>9</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>16</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Coughing</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>7</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> <content styleCode="bold">Skin and Appendages</content> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "/> <td/> <td/> <td/> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Hot Flushes</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>6</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>4</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Lrule Rrule "> <paragraph> Rash<sup>3</sup> </paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>4</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>3</paragraph> </td> <td align="center" valign="top" styleCode=" Lrule Rrule "> <paragraph>12</paragraph> </td> </tr> <tr> <td valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph> Pruritus</paragraph> </td> <td align="center" valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph>1</paragraph> </td> <td align="center" valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph>2</paragraph> </td> <td align="center" valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph>5</paragraph> </td> <td align="center" valign="top" styleCode=" Botrule Lrule Rrule "> <paragraph>3</paragraph> </td> </tr> </tbody> </table>
Reported adverse events (FAERS/openFDA)# Adverse event summaries are temporarily unavailable. Other product information remains available.