Warnings for Tolak
Included as part of the "PRECAUTIONS" Section
Precautions for Tolak
Application Site Adverse Reactions
Application site reactions (erythema, scaling/dryness, edema, crusting, erosions, stinging/burning, and pruritus) were observed in almost all patients during treatment of actinic keratosis on the face, ears, and/or scalp with topical fluorouracil [see ADVERSE REACTIONS]. In the clinical trials of Tolak Cream, application site irritation returned to baseline (pre-treatment) levels within 4 weeks after discontinuing treatment.
Do not apply Tolak Cream directly into eyes, nose, mouth, or other mucous membranes because irritation, local inflammation and ulceration can occur.
Hypersensitivity Reactions
Allergic contact dermatitis (delayed type hypersensitivity reaction) has been noted for topical fluorouracil drugs. While application site reactions are observed in almost all patients during treatment of actinic keratosis with topical fluorouracil [see ADVERSE REACTIONS], delayed type hypersensitivity should be suspected in the event of severe pruritus or eczema at the application site or at a distant site. Although the potential for a delayed hypersensitivity reaction to fluorouracil exists, patch testing to confirm hypersensitivity may be inconclusive.
Tolak Cream contains peanut oil. If signs of hypersensitivity occur, patients should discontinue Tolak Cream immediately and contact their healthcare provider.
Ophthalmic Adverse Reactions
Corneal and conjunctival disorders have occurred with topical fluorouracil use [see ADVERSE REACTIONS]. Avoid application to the periocular area. To avoid transfer of the drug into the eyes and to the periocular area during and after application, patients should wash hands well after applying Tolak Cream. If accidental exposure occurs, the patient should flush eye(s) with large amounts of water and seek medical care as soon as possible.
Photosensitivity
Topical fluorouracil is associated with photosensitivity reactions including severe sunburn. Minimize exposure to ultraviolet rays including sunlight, sun lamps, and tanning beds during and immediately following treatment with Tolak Cream because the intensity of the photosensitivity reaction may be increased.
Embryofetal Toxicity
Cases of miscarriage and birth defects (including cleft lip and cleft palate) have been reported when pregnant women were exposed to a topical or parenteral fluorouracil product. In addition, ventricular septal defect and cases of miscarriage occurred when pregnant women applied a topical fluorouracil product to mucous membranes (Tolak Cream is not indicated for use on the mucous membrane). Furthermore, fluorouracil interferes with the synthesis of deoxyribonucleic acid (DNA), inhibits the formation of ribonucleic acid (RNA), and provokes unbalanced growth and death of cells. Therefore, Tolak Cream is contraindicated in pregnancy.
Advise females of reproductive potential to use effective contraception during Tolak use and for one month after the last dose of Tolak Cream.
Toxicity In Patients With Dihydropyrimidine Dehydrogenase Deficiency
Life-threatening systemic toxicity has been reported with the topical use of fluorouracil in a patient with DPD deficiency. Symptoms included severe abdominal pain, bloody diarrhea, vomiting, fever, and chills. Physical examination revealed stomatitis, erythematous skin rash, neutropenia, thrombocytopenia, inflammation of the esophagus, stomach and small bowel.
A large percentage of fluorouracil is catabolized by the DPD enzyme. DPD enzyme deficiency may result in increased availability of fluorouracil to the anabolic pathway, which may lead to increased interference with DNA and RNA synthesis and increased cytotoxic activity and potential toxicities [see CLINICAL PHARMACOLOGY]. Therefore, Tolak Cream is contraindicated in patients with DPD deficiency.
Patients should discontinue Tolak Cream if symptoms of fluorouracil's systemic toxicity develop.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).
Important Administration Instructions
Advise patients of the following:
- Tolak Cream is for external use only.
- Do not apply to eyes, nose, mouth or mucous membranes.
- Avoid inadvertent transfer of Tolak Cream to other body areas, or to another person.
- Keep out of the reach of children.
- Fluorouracil, including Tolak may be fatal if ingested by pets. Avoid allowing pets to contact the Tolak container or the skin where Tolak has been applied. Store Tolak out of reach of pets. Safely discard or clean any cloth or applicator that may retain Tolak and avoid leaving any residues of Tolak on your hands, clothing, carpeting or furniture.
Instruct patients to do the following:
- Apply after washing, rinsing, and drying the treatment area.
- Wash hands thoroughly after application.
Hypersensitivity Reactions
- Inform patients that Tolak Cream contains peanut oil and that hypersensitivity reactions may occur with its use.
- Inform patients to discontinue Tolak Cream immediately and seek medical attention if signs of severe hypersensitivity occur [see WARNINGS AND PRECAUTIONS].
Ophthalmic Adverse Reactions
- Inform patients that ophthalmic adverse reactions can occur with Tolak Cream use.
- Advise patients that Tolak Cream is not for ophthalmic use.
- Advise patients to avoid application around the eyes.
- If accidental exposure occurs, advise patients to flush eye(s) with large amounts of water and seek medical care [see WARNINGS AND PRECAUTIONS].
Increased Sensitivity To UV Light
- Inform patients that topical fluorouracil is associated with photosensitivity reactions including severe sunburn.
- Advise patients to minimize exposure to sun, sun lamps, and tanning beds while using Tolak Cream.
- Advise patients that sunscreens may be applied after Tolak Cream application [see WARNINGS AND PRECAUTIONS].
Embryofetal Toxicity
- Inform females of reproductive potential of the potential risk to a fetus.
- Advise females of reproductive potential to use effective contraception during and for one month after the last dose of Tolak Cream and to inform their healthcare provider of a known or suspected pregnancy [see WARNINGS AND PRECAUTIONS].
Systemic Toxicity In Patients With DPD Deficiency
- Advise patient to stop using Tolak immediately and contact physician if abdominal (stomach) pain, bloody diarrhea, vomiting, fever, and/or chills occur with Tolak Cream use.
- Inform patient that these symptoms could be manifestations of a deficiency in the enzyme dihydropyrimidine dehydrogenase (DPD) [see WARNINGS AND PRECAUTIONS].
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Adequate long-term studies in animals to evaluate carcinogenic potential of fluorouracil have not been conducted. Studies with the active ingredient of Tolak, fluorouracil, have shown mutagenic effects in in vitro and in vivo tests and impairment of fertility in in vivo animal studies.
Fluorouracil was positive in three in vitro cell neoplastic transformation assays. In the C3H/10T½ clone 8 mouse embryo cell system, the resulting morphologically transformed cells formed tumors when inoculated into immunosuppressed syngeneic mice.
Although no evidence for mutagenic activity of fluorouracil was observed in 3 studies utilizing the Ames test, mutagenic activity was observed in the survival count rec-assay with Bacillus subtilis and in the Drosophila wing-hair spot test. Fluorouracil produced petite mutations in Saccharomyces cerevisiae and demonstrated positive results in the micronucleus test using bone marrow cells of male mice.
Fluorouracil demonstrated clastogenic activity in vitro in Chinese hamster fibroblasts at concentrations of 1.0 and 2.0 μg/mL and was associated with chromatid gaps, breaks, and exchanges. In human lymphocytes, fluorouracil increased sister chromatid exchange in vitro. Additionally, an increase in numerical and structural chromosome aberrations have been observed in peripheral lymphocytes of patients treated with 5-fluorouracil.
In rats, chromosomal abnormalities and changes in chromosome organization in spermatogonia have been observed after intraperitoneal administration of 125 to 250 mg/kg of fluorouracil. Spermatogonial differentiation was also inhibited and resulted in transient infertility. Fluorouracil was inactive, however, at oral doses of 5 to 80 mg/kg/day in studies with a strain of mouse which is sensitive to the induction of sperm head abnormalities after exposure to a range of chemical mutagens and carcinogens. In female rats, fluorouracil administered intraperitoneally at doses of 25 and 50 mg/kg during the preovulatory phase of oogenesis resulted in a significant reduction in the incidence of fertile matings, a delay in the development of preimplantation and postimplantation embryos, an increased incidence of preimplantation lethality, and an induction of chromosomal anomalies in these embryos. In mice, single intravenous or intraperitoneal injections of fluorouracil were toxic to differentiated spermatogonia and spermatocytes (at 500 mg/kg) and produced abnormalities in spermatids (at 50 mg/kg).
Use In Specific Populations
Pregnancy
Teratogenic Effects
Pregnancy Category X [see CONTRAINDICATIONS].
Cases of miscarriage and birth defects (including cleft lip and cleft palate) have been reported when pregnant women were exposed to a topical or parenteral fluorouracil product. In addition, ventricular septal defect and cases of miscarriage occurred when pregnant women applied a topical fluorouracil product to mucous membranes (Tolak Cream is not indicated for use on the mucous membrane).
Animal reproduction studies have not been conducted with Tolak Cream. Fluorouracil administered parenterally has been shown to be teratogenic in mice, rats, and hamsters when given at doses equivalent to the usual human intravenous dose. However, the amount of fluorouracil absorbed systemically after topical administration to actinic keratosis is minimal [see CLINICAL PHARMACOLOGY]. Fluorouracil exhibited maximum teratogenicity when given to mice as single intraperitoneal injections of 10 to 40 mg/kg on day 10 or 12 of gestation. Similarly, intraperitoneal doses of 12 to 37 mg/kg given to rats between days 9 and 12 of gestation and intramuscular doses of 3 to 9 mg/kg given to hamsters between days 8 and 11 of gestation were teratogenic and/or embryotoxic (i.e., resulted in increased resorptions or embryolethality). In monkeys, divided doses of 40 mg/kg given between days 20 and 24 of gestation were not teratogenic. However, doses higher than 40 mg/kg resulted in spontaneous abortions. Based on the recommended human dose and instructions for use, it is not possible tocalculate human dose equivalents for animal exposures in these studies.
Nursing Mothers
Because many drugs are excreted in human milk and there is some systemic absorption of fluorouracil after topical administration, and because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue drug use, taking into account the importance of the drug to the mother.
Pediatric Use
Actinic keratosis is not usually observed in the pediatric population except in the case of rare genetic diseases. Tolak Cream is not intended for use in pediatric patients. Safety and effectiveness in children have not been established.
Geriatric Use
No dose adjustment is required for elderly patients [see Clinical Studies]. The mean age of the 403 subjects treated with Tolak Cream in the clinical trials was 68 years. Of the Tolak Cream-treated subjects, 61% were 65 and over, while 28% were 75 and over.
No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.