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soltamox

Soltamox (Tamoxifen Citrate) is a medication used to treat Breast Neoplasms, Gynecomastia, Pancreatic Neoplasms, Precocious Puberty.

Tamoxifen Citrate · by Mayne Pharma Commrcl

Available as a generic: Tamoxifen Citrate

Not yet rated· sourced from the FDA label
Rated against independent regulatory sources·Last updated June 7, 2026·How we rate
Verified againstopenFDANIH DailyMedRxClass
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Key facts

Active ingredient
Tamoxifen Citrate
Form
Liquid
Strength
Tamoxifen Citrate EQ 20MG BASE/10ML
Type
Prescription (Rx)
Brand or generic
Brand-name
What the pharmacy pays
~$8.28 for 30 — not your price
FDA application
NDA021807

What is Soltamox?

From the FDA label:SOLTAMOX (tamoxifen citrate) oral solution is for oral administration. Tamoxifen citrate is an estrogen agonist/antagonist. Chemically, tamoxifen is the trans-isomer of a triphenylethylene derivative. The chemical name is (Z)2-[4-(1,2- diphenyl-1-butenyl)phenoxy]- N , N -dimethylethanamine 2-hydroxy-1,2,3- propanetricarboxylate (1:1). The structural formula, empirical formula, and molecular weight are as follows: C 32 H 37 NO 8 M.W. 563.62 Tamoxifen citrate has a pKa′ of 8.85. The equilibrium solubility in water at 37°C is 0.5 mg/mL, and is 0.2 mg/mL in 0.02 N HCl at 37°C. Each 10 mL of SOLTAMOX oral solution contains 20 mg tamoxifen, equivalent to 30.4 mg tamoxifen citrate. The oral solution is a sugar-free, clear colorless liquid, with licorice and aniseed odor and taste supplied in a 150 mL bottle with a dosing cup. SOLTAMOX oral solution contains the following inactive ingredients: ethanol, glycerol, propylene glycol, sorbitol solution, licorice flavor, aniseed flavor, purified water. Chemical Structure

How to use

Metastatic breast cancer: 20-40 mg per day. For doses greater than 20 mg per day, administer in divided doses (morning and evening). ( 2 ) Adjuvant treatment of breast cancer, DCIS, reduction of breast cancer incidence in women at high risk: 20 mg per day ( 2 ) Metastatic Breast Cancer For patients with breast cancer, the recommended daily dose of SOLTAMOX is 20 to 40 mg. Doses greater than 20 mg per day should be given in divided doses (morning and evening). Adjuvant Treatment of Breast Cancer For use in the adjuvant setting, the recommended dose of SOLTAMOX is 20 mg daily for 5-10 years [see Clinical Studies (14.2) ] . Doses greater than 20 mg daily yield no additional clinical benefit. Ductal Carcinoma in Situ For patients with DCIS, the recommended dose of SOLTAMOX is 20 mg daily for 5 years. Reduction in Breast Cancer Incidence in Women at High Risk In the risk reduction setting, the recommended dose of SOLTAMOX is 20 mg daily for 5 years .

Side effects

The following serious adverse reactions are discussed below and elsewhere in the labeling: Uterine malignancies [see Boxed Warning , Warnings and Precautions (5.1) , and Clinical Studies (14.4) ] Thromboembolic events [see Boxed Warning , Warnings and Precautions (5.2) , and Clinical Studies (14.4) ] Embryo-Fetal Toxicity [see Warnings and Precautions (5.3) , and Use in Specific Populations (8.1 , 8.3) ] Liver cancer [see Warnings and Precautions (5.4) ] Most common adverse reactions: hot flashes, mood disturbances, vaginal discharge, vaginal bleeding, nausea, and fluid retention ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Mayne Pharma at 1-844-825-8500 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adverse Reactions in Patients with Metastatic Breast Cancer In patients treated with tamoxifen for metastatic breast cancer, the most frequent adverse reaction was hot flashes. Other adverse reactions which were seen less commonly are hypercalcemia, peripheral edema, distaste for food, pruritus vulvae, depression, dizziness, lightheadedness, headache, hair thinning and/or…

FDA Boxed Warning (the FDA’s most serious warning)

Boxed (black-box) warning — from the FDA label

UTERINE MALIGNANCIES and THROMBOEMBOLIC EVENTS Serious and life-threatening events from the use of SOLTAMOX include uterine malignancies, stroke, and pulmonary embolism [see Warnings and Precautions (5.1 , 5.2) ] . Fatal cases of each type of event have occurred. Incidence rates per 1000 women-years for these events were estimated from the National Surgical Adjuvant Breast and Bowel Project (NSABP) P-1 trial in women at high risk for breast cancer [see Clinical Studies (14.4) ] : Endometrial adenocarcinoma: 2.20 for tamoxifen vs. 0.71 for placebo Uterine sarcoma: 0.17 for tamoxifen vs. 0.04 for placebo Stroke: 1.43 for tamoxifen vs. 1.00 for placebo. Pulmonary embolism: 0.75 for tamoxifen versus 0.25 for placebo. Discuss the potential benefits of tamoxifen versus the potential risks of these serious events with women at high risk for breast cancer and women with ductal carcinoma in situ (DCIS) considering tamoxifen to reduce the risk of developing breast cancer [see Warnings and Precautions (5) ]. For most patients already diagnosed with breast cancer, the benefits of tamoxifen outweigh its risks. WARNING: UTERINE MALIGNANCIES and THROMBOEMBOLIC EVENTS See full prescribing information for complete boxed warning . Serious, life-threatening, and fatal events from use of tamoxifen include uterine malignancies, stroke, and pulmonary embolism. ( 5.1 , 5.2 ) Discuss risks and benefits of tamoxifen with women at high risk for breast cancer and women with ductal carcinoma in situ (DCIS) when considering tamoxifen use to reduce the risk of developing breast cancer. ( 5.1 , 5.2 ) For most patients already diagnosed with breast cancer, the benefits of tamoxifen outweigh its risks. ( 5.1 , 5.2 )

Warnings

Important safety information

Uterine malignancies: Promptly evaluate abnormal vaginal bleeding in a woman with current or past tamoxifen use. ( 5.1 ) Thromboembolic events: Risk increases with coadministered chemotherapy. For treatment of breast cancer, consider risks and benefits in patients with a history of thromboembolic events. ( 5.2 ) Embryo-fetal toxicity: Can cause fetal harm. Advise females of reproductive potential of the potential risk to a fetus and to use effective contraception. ( 5.3 , 8.1 , 8.3 ) Effects on the liver: Liver cancer and liver abnormalities, some fatal, have occurred. Perform periodic liver function testing. ( 5.4 , 5.9 ) 5.1 Endometrial Cancer, Uterine Sarcoma, and Other Effects on the Uterus Endometrial Cancer and Uterine Sarcoma An increased incidence of uterine malignancies (endometrial adenocarcinoma and uterine sarcoma), including fatal cases, has been reported with tamoxifen treatment. The underlying mechanism is unknown, but may be related to the estrogen-like effect of tamoxifen. Most uterine malignancies seen with tamoxifen are classified as adenocarcinoma of the endometrium; however, uterine sarcomas, including malignant mixed mullerian tumors (MMMT), have also been reported. Uterine sarcoma was generally associated with a higher FIGO stage (III/IV) at diagnosis, poor prognosis, and short survival. Uterine sarcoma has been reported to occur more frequently among long-term users (≥2 years) of tamoxifen than non-users. Promptly evaluate any patient receiving or who has previously received tamoxifen who reports abnormal vaginal bleeding. Patients receiving or who have previously received tamoxifen should have annual gynecological examinations. Advise patients to promptly inform a healthcare provider if they experience any abnormal gynecological symptoms (e.g., menstrual irregularities, abnormal vaginal bleeding, changes in vaginal discharge, or pelvic pain or pressure). There are no data to suggest that routine endometrial sampling in asymptomatic women taking tamoxifen is beneficial. In a review of long-term data (median length of total follow-up was 6.9 years, including blinded follow-up) on 8,306 women with an intact uterus at randomization in the NSABP P-1 risk reduction trial, the incidence of both adenocarcinomas and uterine sarcomas was increased in women taking tamoxifen. During blinded follow-up, there were 36 cases of FIGO Stage I endometrial adenocarcinoma (22 were FIGO Stage IA, 13 IB, and 1 IC) in women receiving tamoxifen and 15 cases in women receiving placebo [14 were FIGO Stage I (9 IA and 5 IB), and 1 case was FIGO Stage IV]. During total follow-up, endometrial adenocarcinoma was reported in 53 women randomized to tamoxifen (30 cases of FIGO Stage IA, 20 were Stage IB, 1 was Stage IC, and 2 were Stage IIIC), and 17 women randomized to placebo (9 cases were FIGO Stage IA, 6 were Stage IB, 1 was Stage IIIC, and 1 was Stage IVB) (incidence per 1,000 women-years of 2.20 and 0.71, respectively). Uterine sarcomas were reported in 4 women randomized to tamoxifen (1 was FIGO IA, 1 was FIGO IB, 1 was FIGO IIA, and 1 was FIGO IIIC) and 1 patient randomized to placebo (FIGO IA); incidence per 1,000 women-years of 0.17 and 0.04, respectively. Of the patients randomized to tamoxifen, the FIGO IA and IB cases were a MMMT and sarcoma, respectively; the FIGO II was a MMMT; and the FIGO III was a sarcoma; and the 1 patient randomized to placebo had a MMMT. A similar increased incidence in endometrial adenocarcinoma and uterine sarcoma was observed among women receiving tamoxifen in 5 other NSABP clinical trials. In the NSABP P-1 trial, endometrial sampling did not alter the endometrial cancer detection rate compared to women who did not undergo endometrial sampling (0.6% with sampling, 0.5% without sampling) for women who had not undergone hysterectomy. Non-Malignant Effects on the Uterus An increased incidence of endometrial changes including hyperplasia and polyps has been reported with tamoxifen treatment. The incidence and pattern of this increase suggest that the underlying mechanism is related to the partial estrogenic effect of tamoxifen. There have been reports of endometriosis and uterine fibroids in women receiving tamoxifen. Ovarian cysts have also been observed in premenopausal patients with advanced breast cancer who have been treated with tamoxifen. Tamoxifen has been reported to cause menstrual irregularity or amenorrhea. 5.2 Thromboembolic Events There is an increased incidence of thromboembolic events, including deep vein thrombosis and pulmonary embolism, during tamoxifen therapy. When tamoxifen is coadministered with chemotherapy, there is a further increase in the risk of thromboembolic events. For treatment of breast cancer, carefully consider the risks and benefits of tamoxifen in women with a history of thromboembolic events. For women with DCIS and for the reduction in breast cancer incidence in women at high risk, tamoxifen is contraindicated in women who require concomitant warfarin-type anticoagulant therapy or in women with a history of deep vein thrombosis or pulmonary embolus. Advise patients to seek medical attention immediately if signs or symptoms of a thromboembolic event occur. Data from the NSABP P-1 trial in women at high risk for breast cancer show that participants receiving tamoxifen without a history of pulmonary emboli (PE) had a statistically significant increase in pulmonary emboli (events: 18 tamoxifen, 6 placebo; incidence rate per 1,000 women-years: 0.75 tamoxifen versus 0.25 placebo; RR = 3.01, 95% CI: 1.15 to 9.27) [see Clinical Studies (14.4) ]. Three of the pulmonary emboli, all in the tamoxifen arm, were fatal. Eighty-seven percent of the cases of pulmonary embolism occurred in women at least 50 years of age at randomization. Among women receiving tamoxifen, PE events occurred between 2 and 60 months (average = 27 months) from the start of treatment. In this same population, a non-statistically significant increase in deep vein thrombosis (DVT) was seen in the tamoxifen group (30 tamoxifen, 19 placebo; relative risk (RR) = 1.59, 95% CI: 0.86 to 2.98). The same increase in relative risk was seen in women ≤49 and in women ≥50, although fewer events occurred in younger women. Women with thromboembolic events were at risk for a second related event (7 out of 25 women on placebo, 5 out of 48 women on tamoxifen) and were at risk for thromboembolic event and treatment related complications (0/25 on placebo, 4/48 on tamoxifen). Among women receiving tamoxifen, DVT events occurred between 2 and 57 months (average = 19 months) from the start of treatment. In a small substudy (N = 81) of the NSABP-1 trial, there appeared to be no benefit to screening women for Factor V Leiden and Prothrombin mutations G20210A as a means to identify those who may not be appropriate candidates for tamoxifen therapy. In the NSABP P-1 trial, there was an increase in stroke among women randomized to tamoxifen compared to women randomized to placebo (events: 24 placebo; 34 tamoxifen; incidence rate per 1,000 women-years: 1.43 tamoxifen versus 1.00 placebo; RR = 1.42, 95% CI: 0.82 to 2.51). Six of the 24 strokes in the placebo group were considered hemorrhagic in origin and 10 of the 34 strokes in the tamoxifen group were categorized as hemorrhagic. Seventeen of the 34 strokes in the tamoxifen group were considered occlusive and 7 were considered to be of unknown etiology. Fourteen of the 24 strokes on the placebo arm were reported to be occlusive and 4 of unknown etiology. Three strokes in the placebo group and 4 strokes in the tamoxifen group were fatal. Eighty-eight percent of the strokes occurred in women at least 50 years of age at the time of randomization. Among women receiving tamoxifen, the stroke events occurred between 1 and 63 months (average = 30 months) from the start of treatment. 5.3 Embryo-Fetal Toxicity Tamoxifen can cause fetal harm when administered to a pregnant woman. There are postmarketing reports…

Who should not take Soltamox

SOLTAMOX is contraindicated in patients with known hypersensitivity (e.g., angioedema, serious skin reactions) to tamoxifen or any other SOLTAMOX ingredient [see Adverse Reactions (6.2) ] . SOLTAMOX is contraindicated in patients who require concomitant warfarin therapy or have a history of deep vein thrombosis or pulmonary embolus if the indication for treatment is either reduction of breast cancer incidence in high-risk patients or risk reduction of invasive breast cancer after treatment of DCIS [see Warnings and Precautions (5.2) and Drug Interactions (7.2) ]. Known hypersensitivity to tamoxifen or any other SOLTAMOX ingredient ( 4 ) In patients who require concomitant warfarin therapy or have a history of deep vein thrombosis or pulmonary embolus, if the indication for treatment is either reduction of breast cancer incidence in high-risk patients or risk reduction of invasive breast cancer after treatment of DCIS ( 4 )

Overdose — what happens if you take too much

No specific treatment for SOLTAMOX overdosage is recommended, other than symptomatic treatment. In a study of advanced metastatic cancer patients to determine the maximum tolerated dose of tamoxifen that could reverse multidrug resistance, the following adverse events were observed: acute neurotoxicity manifested by tremor, hyperreflexia, unsteady gait, and dizziness. These symptoms occurred within 3 to 5 days of beginning tamoxifen and cleared within 2 to 5 days after stopping therapy. No permanent neurologic toxicity was noted. One patient experienced a seizure several days after tamoxifen was discontinued and neurotoxic symptoms had resolved. The causal relationship of the seizure to tamoxifen therapy is unknown. Doses given in these patients were all greater than 400 mg/m 2 loading dose (at least 6-fold higher than the recommended dosage), followed by maintenance doses of 150 mg/m 2 of tamoxifen given twice a day (at least 6-fold higher than the recommended dosage). In the same study, prolongation of the QT interval on the electrocardiogram was noted when patients were given doses higher than 250 mg/m 2 loading dose (at least 6-fold higher than the recommended dose) , followed by maintenance doses of 80 mg/m 2 of tamoxifen given twice a day. For a woman with a body surface area of 1.5 m 2 , the minimal loading dose and maintenance doses at which neurological symptoms and…

U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.

Interactions

Anastrozole and letrozole: Should not be used in combination with tamoxifen. ( 7.1 ) Warfarin: Do not use in patients taking tamoxifen for DCIS and for reduction in breast cancer incidence in women at high risk. ( 4 ) Closely monitor coagulation indices for increased anticoagulant effect when used with tamoxifen for metastatic breast cancer or as adjuvant therapy. ( 7.2 ) 7.1 Aromatase Inhibitors Anastrozole The combination of anastrozole and tamoxifen did not demonstrate any benefit when compared to tamoxifen alone and should be avoided in all patients [see Clinical Studies (14.2) ] . In the ATAC trial, coadministration of anastrozole and tamoxifen in breast cancer patients reduced the anastrozole plasma concentration by 27% compared to that achieved with anastrozole alone. The tamoxifen concentration was not altered [see Clinical Pharmacology (12.3) ]. Letrozole The concomitant use of letrozole with tamoxifen is not recommended because the efficacy of the combination in the adjuvant treatment of breast cancer has not been established. Tamoxifen reduced the plasma concentration of letrozole by 38% when these drugs were co-administered [see Clinical Pharmacology (12.3) ]. 7.2. Warfarin A marked increase in anticoagulant effect may occur when tamoxifen is used in combination with warfarin. Closely monitor coagulation indices in patients who are taking tamoxifen for either the treatment of metastatic breast cancer or as adjuvant therapy who require concomitant use of warfarin [see Contraindications (4) ] . 7.3 Inducers of CYP3A4 Strong CYP3A4 inducers should not be used with tamoxifen. Strong CYP3A4 inducers (e.g., rifampin) reduce tamoxifen AUC and C max [see Clinical Pharmacology (12.3) ] . 7.4 Strong Inhibitors of CYP2D6 The impact on the efficacy of tamoxifen with co-administration of strong CYP2D6 inhibitors (e.g., paroxetine) is not well established. Some studies have shown that the efficacy of tamoxifen may be reduced when the drugs are co-administered as a result of reduced levels of potent active metabolites of tamoxifen . However, other studies have failed to demonstrate such an effect [see Clinical Pharmacology (12.3) ] . 7.5 Drug-Laboratory Test Interactions There are postmarketing reports of T 4 elevations in postmenopausal patients taking tamoxifen that may be explained by increases in thyroid-binding globulin. These elevations were not accompanied by clinical hyperthyroidism. Variations in the karyopyknotic index on vaginal smears and various degrees of estrogen effect on Pap smears have been seen in postmenopausal patients taking tamoxifen.

May treat (source: NIH RxClass)

Dosage forms

Liquid

The forms currently marketed in the U.S., per the FDA National Drug Code Directory.

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Frequently asked questions

What does Soltamox treat?
Soltamox (Tamoxifen Citrate) may be used to treat breast neoplasms, gynecomastia, pancreatic neoplasms, precocious puberty, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
How much does Soltamox cost?
Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $8.28 for 30, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins. Pharmacies pay less for a same-class option, Arimidex — about $4.15 on the same basis.
Is there a coupon or discount for Soltamox?
pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Soltamox. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
Who makes Soltamox?
Soltamox is marketed by Mayne Pharma Commrcl. You can see Mayne Pharma Commrcl's full profile, rating, and other products on pharmaranks.
Is Soltamox a brand-name or generic drug?
Soltamox is a brand-name product with the active ingredient Tamoxifen Citrate. Lower-cost generic equivalents containing Tamoxifen Citrate are available — ask your pharmacist.
Is Soltamox available over the counter?
No. Soltamox is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
What forms does Soltamox come in?
Soltamox is currently marketed as liquid, per the FDA's National Drug Code Directory.
Is Soltamox FDA-registered?
Soltamox is on record with the U.S. FDA under application number NDA021807. You can verify this on its official FDA label.
Is Soltamox safe?
There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Soltamox. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
What are the side effects of Soltamox?
Soltamox's side effects are taken directly from its FDA label. From the label: The following serious adverse reactions are discussed below and elsewhere in the labeling: Uterine malignancies [see Boxed Warning , Warnings and Precautions (5.1) , and Clinical Studies (14.4) ] Thromboembolic events [see Boxed Warning , Warnings and Precautions (5.2) ,… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.

Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.

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