Adverse drug reactions are principally due to the antiestrogenic actions of FARESTON and typically occur at the beginning of treatment.
The incidences of the following eight clinical toxicities were prospectively assessed in the North American Study. The incidence reflects the toxicities that were considered by the investigator to be drug related or possibly drug related.
| | North American Study |
| | FAR60 | TAM20 |
| | n = 221 | n = 215 |
| Hot Flashes | 35% | 30% |
| Sweating | 20% | 17% |
| Nausea | 14% | 15% |
| Vaginal Discharge | 13% | 16% |
| Dizziness | 9% | 7% |
| Edema | 5% | 5% |
| Vomiting | 4% | 2% |
| Vaginal Bleeding | 2% | 4% |
Approximately 1% of patients receiving FARESTON (n = 592) in the three controlled studies discontinued treatment as a result of adverse reactions (nausea and vomiting, fatigue, thrombophlebitis, depression, lethargy, anorexia, ischemic attack, arthritis, pulmonary embolism, and myocardial infarction).
Serious adverse reactions occurring in at least 1% of patients receiving FARESTON in the three major trials are listed in the table below.
Three prospective, randomized, controlled clinical studies (North American, Eastern European, and Nordic) were conducted. The patients were randomized to parallel groups receiving FARESTON 60 mg (FAR60) or tamoxifen 20 mg (TAM20) in the North American Study or tamoxifen 40 mg (TAM40) in the Eastern European and Nordic studies. The North American and Eastern European studies also included high-dose toremifene arms of 200 and 240 mg daily, respectively [see Clinical Studies (14)].
* Most of the ocular abnormalities were observed in the North American Study in which on-study and biannual ophthalmic examinations were performed. No cases of retinopathy were observed in any arm. ** Elevated defined as follows: North American Study: AST >100 IU/L; alkaline phosphatase >200 IU/L; bilirubin > 2 mg/dL. Eastern European and Nordic studies: AST, alkaline phosphatase, and bilirubin - WHO Grade 1 (1.25 times the upper limit of normal). |
| Adverse Reactions | North American | Eastern European | Nordic |
| | FAR60 | TAM20 | FAR60 | TAM40 | FAR60 | TAM40 |
| | n=221(%) | n=215(%) | n=157(%) | n=149(%) | n=214(%) | n=201(%) |
| Cardiac | | | | | | |
| Cardiac Failure | 2 (1) | 1 (<1) | - | 1 (<1) | 2 (1) | 3 (1.5) |
| Myocardial Infarction | 2 (1) | 3 (1.5) | 1 (<1) | 2 (1) | - | 1 (<1) |
| Arrhythmia | - | - | - | - | 3 (1.5) | 1 (<1) |
| Angina Pectoris | - | - | 1 (<1) | - | 1 (<1) | 2 (1) |
| Ocular* | | | | | | |
| Cataracts | 22 (10) | 16 (7.5) | - | - | - | 5 (3) |
| Dry Eyes | 20 (9) | 16 (7.5) | - | - | - | - |
| Abnormal Visual Fields | 8 (4) | 10 (5) | - | - | - | 1 (<1) |
| Corneal Keratopathy | 4 (2) | 2 (1) | - | - | - | - |
| Glaucoma | 3 (1.5) | 2 (1) | 1 (<1) | - | - | 1 (<1) |
| Abnormal Vision/Diplopia | - | - | - | - | 3 (1.5) | - |
| Thromboembolic | | | | | | |
| Pulmonary Embolism | 4 (2) | 2 (1) | 1 (<1) | - | - | 1 (<1) |
| Thrombophlebitis | - | 2 (1) | 1 (<1) | 1 (<1) | 4 (2) | 3 (1.5) |
| Thrombosis | - | 1 (<1) | 1 (<1) | - | 3 (1.5) | 4 (2) |
| CVA/TIA | 1 (<1) | - | - | 1 (<1) | 4 (2) | 4 (2) |
| Elevated Liver Tests** | | | | | | |
| AST | 11 (5) | 4 (2) | 30 (19) | 22 (15) | 32 (15) | 35 (17) |
| Alkaline Phosphatase | 41 (19) | 24 (11) | 16 (10) | 13 (9) | 18 (8) | 31 (15) |
| Bilirubin | 3 (1.5) | 4 (2) | 2 (1) | 1 (<1) | 2 (1) | 3 (1.5) |
| Hypercalcemia | 6 (3) | 6 (3) | 1 (<1) | - | - | - |
Other adverse reactions included leukopenia and thrombocytopenia, skin discoloration or dermatitis, constipation, dyspnea, paresis, tremor, vertigo, pruritus, anorexia, reversible corneal opacity (corneal verticulata), asthenia, alopecia, depression, jaundice, and rigors.
The incidence of AST elevations was greater in the 200 and 240 mg FARESTON dose arms than in the tamoxifen arms. Higher doses of FARESTON were also associated with an increase in nausea.
Approximately 4% of patients were withdrawn for toxicity from the high-dose FARESTON treatment arms. Reasons for withdrawal included hypercalcemia, abnormal liver function tests, and one case each of toxic hepatitis, depression, dizziness, incoordination, ataxia, blurry vision, diffuse dermatitis, and a constellation of symptoms consisting of nausea, sweating, and tremor.