vismodegib

General

Pronunciation:
vis-moe-deg-ib

Trade Name(s)

• Erivedge

Ther. Class.
antineoplastics

Pharm. Class.
hedgehog pathway inhibitors

Indications

Metastatic basal cell carcinoma or locally advanced basal cell carcinoma which has recurred in patients who are not candidates for further surgery or radiation.

Action

Inhibits the hedgehog signaling pathway; binds/inhibits a transmembrane protein involved in Hedgehog signal transduction.

Therapeutic Effect(s):

Decreased spread of basal cell carcinoma.

Pharmacokinetics

Absorption: 31.8% absorbed following oral administration, absorption is saturable.

Distribution: Unknown.

Protein Binding: >99%.

Metabolism and Excretion: Mostly metabolized, eliminated by the liver; 83% excreted in feces, 4.4% in urine.

Half-life: 4 days (continuous once-daily dosing), 12 days (single dose).

TIME/ACTION PROFILE (response))

Contraindication/Precautions

Contraindicated in:

• OB:  Pregnancy (can cause embryo-fetal death or severe birth defects)
• Lactation: Avoid breastfeeding
• Blood donation;
• Rep:  Sperm donation (avoid during therapy and for 3 mo following last dose).

Use Cautiously in:

• Rep:  Women of reproductive potential
• Pedi:  Safety and effectiveness not established.

Adverse Reactions/Side Effects

CNS: fatigue

GI: ↓ appetite, constipation, diarrhea, impaired taste, nausea, vomiting

GU: amenorrhea, azotemia

Derm: alopecia

F and E: hypokalemia, hyponatremia

Metabolic: weight loss

MS: arthralgias, muscle spasms

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

None reported. .

Route/Dosage

PO (Adults): 150 mg once daily continued until disease progression or unacceptable toxicity.

Availability

Capsules: 150 mg

Assessment

• Monitor for diarrhea and vomiting. Maintain adequate hydration and electrolyte balance.

Lab Test Considerations: Obtain a pregnancy test within 7 days of starting vismodegib.

• May cause hyponatremia, hypokalemia, and azotemia.

Potential Diagnoses

• Impaired skin integrity (Indications) 
• Deficient knowledge, related to medication regimen (Patient/Family/Teaching) 

Implementation

• PO Administer once daily without regard to food. Swallow capsule whole; do not open, crush, or chew.

Patient/Family Teaching

• Instruct patient to take as directed. If a dose is missed, skip missed dose. Do not make up dose. Resume dosing with next scheduled dose.
• Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
• Discuss the possibility of hair loss with patient. Explore methods of coping.
• Advise patient not to donate blood during therapy and for at least 24 mo after last dose.
• Rep:  Vismodegib can cause fetal harm. Advise male and female patient to use a highly effective method (IUD, hormonal contraceptive, tubal ligation, partner's vasectomy) of contraception during and for at least 24 mo after therapy for women. Male patients receiving vismodegib must always use condoms with spermicide during any contact with females with child-bearing potential, even if they have undergone a successful vasectomy, and may not donate sperm during and for at least 3 mo after completion of therapy. Instruct patient to notify health care professional promptly if pregnancy is suspected or if breastfeeding. Advise women to avoid breastfeeding during and for 24 mo after final dose of vismodegib. May cause amenorrhea with unknown reversibility. Encourage women who have been exposed to vismodegib either directly or through seminal fluid, to participate in ERIVEDGE pregnancy pharmacovigilance program by contacting the Genentech Adverse Event Line at 1-888-835-2555.

Evaluation/Desired Outcomes

Decreased spread of basal cell carcinoma.