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Last reviewed on RxList: 1/30/2017
Soltamox Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Last reviewed on RxList 3/17/2016

Soltamox (tamoxifen citrate) Oral Solution is a nonsteroidal antiestrogen used to treat some types of breast cancer in men and women. Soltamox is also used to lower a woman's chance of developing breast cancer if she has a high risk (such as a family history of breast cancer). Common side effects of Soltamox include:

  • hot flashes
  • nausea
  • leg cramps
  • muscle aches
  • hair thinning
  • headache bone
  • pain joint
  • pain
  • tumor pain
  • swelling in your hands or feet
  • vaginal itching or dryness
  • changes in menstrual periods
  • dizziness depression
  • weight loss
  • swelling/fluid retention
  • loss of sexual ability/interest
  •  impotence, or
  • difficulty having an orgasm

For patients with breast cancer the recommended daily dose of Soltamox is 20-40 mg. Soltamox may interact with bromocriptine cimetidine clozapine cyclophosphamide isoniazid letrozole methimazole nicardipine pioglitazone rifampin ropinirole ticlopidine tranylcypromine anti-malaria medications antibiotics antidepressants heart rhythm medications HIV or AIDS medicines or medicines to treat psychiatric disorders. Tell your doctor all medications and supplements you use. Soltamox is not recommended for use during pregnancy because it may harm a fetus. Women should start Soltamox during their periods or get a negative pregnancy test before starting the medication. It is recommended that men and women using Soltamox use two non-hormonal forms of birth control (e.g. condoms and diaphragms with spermicide) while taking this medication and for 2 months after stopping the medication. Consult your doctor. It is unknown if this drug passes into breast milk. Because of the potential risk to the infant breastfeeding is not recommended while using Soltamox.

Our Soltamox (tamoxifen citrate) Oral Solution Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Soltamox Consumer Information

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using tamoxifen and call your doctor at once if you have a serious side effect such as:

  • sudden numbness or weakness, especially on one side of the body;
  • sudden severe headache, confusion, problems with vision, speech, or balance;
  • chest pain, sudden cough, wheezing, rapid breathing, fast heart rate;
  • pain, swelling, warmth, or redness in one or both legs;
  • nausea, loss of appetite, increased thirst, muscle weakness, confusion, and feeling tired or restless;
  • unusual vaginal bleeding or discharge;
  • irregular menstrual periods;
  • pain or pressure in your pelvic area;
  • blurred vision, eye pain, or seeing halos around lights;
  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;
  • fever, chills, body aches, flu symptoms;
  • new breast lump; or
  • upper stomach pain, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

  • hot flashes;
  • bone pain, joint pain, or tumor pain;
  • swelling in your hands or feet;
  • vaginal itching or dryness;
  • decreased sex drive, impotence, or difficulty having an orgasm;
  • headache, dizziness, depression; or
  • thinning hair.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Soltamox (Tamoxifen Citrate)

Soltamox Professional Information


Adverse reactions to tamoxifen are relatively mild and rarely severe enough to require discontinuation of treatment in breast cancer patients.

Continued clinical studies have resulted in further information which better indicates the incidence of adverse reactions with tamoxifen as compared to placebo.

In one single-dose pharmacokinetic study in healthy perimenopausal and postmenopausal female volunteers, throat irritation was reported by 3 of 60 evaluable subjects (5.0%) in the SOLTAMOX™ (tamoxifen citrate) treatment groups while none of the subjects in the tamoxifen reference group reported this event. All events were mild and occurred within an hour after dosing. All events were resolved within 24 hours.

Metastatic Breast Cancer

Increased bone and tumor pain and, also, local disease flare have occurred, which are sometimes associated with a good tumor response. Patients with increased bone pain may require additional analgesics. Patients with soft tissue disease may have sudden increases in the size of preexisting lesions, sometimes associated with marked erythema within and surrounding the lesions and/or the development of new lesions. When they occur, the bone pain or disease flare are seen shortly after starting tamoxifen and generally subside rapidly.

In patients treated with tamoxifen for metastatic breast cancer, the most frequent adverse reaction to tamoxifen is hot flashes.

Other adverse reactions which are seen infrequently are hypercalcemia, peripheral edema, distaste for food, pruritus vulvae, depression, dizziness, light-headedness, headache, hair thinning and/or partial hair loss, and vaginal dryness.

Premenopausal Women

The following table summarizes the incidence of adverse reactions reported at a frequency of 2% or greater from clinical trials (Ingle, Pritchard, Buchanan) which compared tamoxifen therapy to ovarian ablation in premenopausal patients with metastatic breast cancer.

Adverse Reactions* TAMOXIFEN
All Effects
% of Women
n =104
All Effects
% of Women
n = 100
Flush 33 46
Amenorrhea 16 69
Altered Menses 13 5
Oligomenorrhea 9 1
Bone Pain 6 6
Menstrual Disorder 6 4
Nausea 5 4
Cough/Coughing 4 1
Edema 4 1
Fatigue 4 1
Musculoskeletal Pain 3 0
Pain 3 4
Ovarian Cyst(s) 3 2
Depression 2 2
Abdominal Cramps I 2
Anorexia 1 2
*Some women had more than one adverse reaction.

Male Breast Cancer

Tamoxifen is well tolerated in males with breast cancer. Reports from the literature and case reports suggest that the safety profile of tamoxifen in males is similar to that seen in women. Loss of libido and impotence have resulted in discontinuation of tamoxifen therapy in male patients. Also, in oligospermic males treated with tamoxifen, LH, FSH, testosterone and estrogen levels were elevated. No significant clinical changes were reported.

Adjuvant Breast Cancer

In the NSABP B-14 study, women with axillary node-negative breast cancer were randomized to 5 years of tamoxifen 20 mg/day or placebo following primary surgery. The reported adverse effects are tabulated below (mean follow-up of approximately 6.8 years) showing adverse events more common on tamoxifen than on placebo. The incidence of hot flashes (64% vs. 48%), vaginal discharge (30% vs. 15%), and irregular menses (25% vs. 19%) were higher with tamoxifen compared with placebo. All other adverse effects occurred with similar frequency in the 2 treatment groups, with the exception of thrombotic events; a higher incidence was seen in tamoxifen-treated patients (through 5 years, 1.7% vs. 0.4%). Two of the patients treated with tamoxifen who had thrombotic events died.

In the Eastern Cooperative Oncology Group (ECOG) adjuvant breast cancer trial, tamoxifen or placebo was administered for 2 years to women following mastectomy. When compared to placebo, tamoxifen showed a significantly higher incidence of hot flashes (19% vs. 8% for placebo). The incidence of all other adverse reactions was similar in the 2 treatment groups with the exception of thrombocytopenia where the incidence for tamoxifen was 10% vs. 3% for placebo, an observation of borderline statistical significance.

NSABPB-14 Study

  % of Women
(n=1422) (n=1437)
Hot Flashes 64 48
Fluid Retention 32 30
Vaginal Discharge 30 15
Nausea 26 24
Irregular Menses 25 19
Weight Loss (>5%) 23 18
Skin Changes 19 15
Increased SGOT 5 3
Increased Bilirubin 2 1
Increased Creatinine 2 1
Thrombocytopenia* 2 1
Thrombotic Events  
   Deep Vein Thrombosis 0.8 0.2
   Pulmonary Embolism 0.5 0.2
   Superficial Phlebitis 0.4 0.0
* Defined as a platelet count of < 100,000/mm3

In other adjuvant studies, Toronto and tamoxifen Adjuvant Trial Organization (NATO), women received either tamoxifen or no therapy. In the Toronto study, hot flashes were observed in 29% of patients for tamoxifen vs. 1% in the untreated group. In the NATO trial, hot flashes and vaginal bleeding were reported in 2.8% and 2.0% of women, respectively, for tamoxifen vs. 0.2% for each in the untreated group.

Ductal Carcinoma in Situ (DCIS)

The type and frequency of adverse events in the NSABP B-24 trial were consistent with those observed in the other adjuvant trials conducted with tamoxifen.

Reduction in Breast Cancer Incidence in High Risk Women

In the NSABP P-1 Trial, there was an increase in five serious adverse effects in the tamoxifen group: endometrial cancer (33 cases in the tamoxifen group vs. 14 in the placebo group); pulmonary embolism (18 cases in the tamoxifen group vs. 6 in the placebo group); deep vein thrombosis (30 cases in the tamoxifen group vs. 19 in the placebo group); stroke (34 cases in the tamoxifen group vs. 24 in the placebo group); cataract formation (540 cases in the tamoxifen group vs. 483 in the placebo group) and cataract surgery (101 cases in the tamoxifen group vs. 63 in the placebo group) (See WARNINGS and Table 3 in CLINICAL PHARMACOLOGY).

The following table presents the adverse events observed in NSABP P-1 by treatment arm. Only adverse events more common on tamoxifen than placebo are shown.

NSABP P-l Trial: All Adverse Events

  % of Women
Self Reported Symptoms N=64411 N=64691
Hot Flashes 80 68
Vaginal Discharges 55 35
Vaginal Bleeding 23 22
Laboratory Abnormalities N=65202 N=65352
Platelets decreased 0.7 0.3
Adverse Effects N=64923 N=64843
Other Toxicities  
Mood 11.6 10.8
Infection/Sepsis 6.0 5.1
Constipation 4.4 3.2
Alopecia 5.2 4.4
Skin 5.6 4.7
Allergy 2.5 2.1
1Number with Quality of Life Questionnaires
2Numbcr with Treatment Follow-up Forms
3Number with Adverse Drug Reaction Forms

In the NSABP P-1 trial, 15.0% and 9.7% of participants receiving tamoxifen and placebo therapy, respectively, withdrew from the trial for medical reasons. The following are the medical reasons for withdrawing from tamoxifen and placebo therapy, respectively: Hot flashes (3.1% vs. 1.5%) and Vaginal Discharge (0.5% vs. 0.1%).

In the NSABP P-1 trial, 8.7% and 9.6% of participants receiving tamoxifen and placebo therapy, respectively, withdrew for non-medical reasons.

On the NSABP P-1 trial, hot flashes of any severity occurred in 68% of women on placebo and in 80% of women on tamoxifen. Severe hot flashes occurred in 28% of women on placebo and 45% of women on tamoxifen. Vaginal discharge occurred in 35% and 55% of women on placebo and tamoxifen respectively; and was severe in 4.5% and 12.3% respectively. There was no difference in the incidence of vaginal bleeding between treatment arms.

Postmarketing Experience

Less frequently reported adverse reactions are vaginal bleeding, vaginal discharge, menstrual irregularities, skin rash and headaches. Usually these have not been of sufficient severity to require dosage reduction or discontinuation of treatment. Very rare reports of erythema multiforme, Stevens-Johnson syndrome, bullous pemphigoid, interstitial pneumonitis, and rare reports of hypersensitivity reactions including angioedema have been reported with tamoxifen therapy. In some of these cases, the time to onset was more than one year. Rarely, elevation of serum triglyceride levels, in some cases with pancreatitis, may be associated with the use of tamoxifen (see PRECAUTIONS, Drug/Laboratory Testing Interactions section).

Read the entire FDA prescribing information for Soltamox (Tamoxifen Citrate)

Related Resources for Soltamox

© Soltamox Patient Information is supplied by Cerner Multum, Inc. and Soltamox Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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