mechlorethamine, topical

mechlorethamine, topical

(mech-klor-eh-tha-meen),

Valchlor

(trade name)

Classification

Therapeutic: antineoplastics
Pharmacologic: alkylating agents
Pregnancy Category: D

Indications

Topical treatment of Stage IA and IB mycosis fungoides-type cutaneous T-cell lymphoma in patients who have already received skin-directed treatment.

Action

Interferes with DNA and RNA synthesis by cross-linking strands (cell-cycle phase–nonspecific).

Therapeutic effects

Death of rapidly replicating cells, particularly malignant ones.

Pharmacokinetics

Absorption: Systemic absorption is not detectable following topical administration.
Distribution: Unknown.
Metabolism and Excretion: Systemically administered mechlorethamine is rapidly degraded in body tissues and fluids.
Half-life: Unknown.

Time/action profile (improvement in lesions)

ROUTEONSETPEAKDURATI
Top1–11 mosunknownunknown

Contraindications/Precautions

Contraindicated in: Severe hypersensitivity; Lactation: Breastfeeding should be avoided; Obstetric: Pregnancy (systemic exposure causes fetal harm).
Use Cautiously in: Patients with reproductive potential; Pediatric: Safe and effective use in children has not been established.

Adverse Reactions/Side Effects

Dermatologic

  • dermatitis (most frequent)
  • bacterial skin infection
  • hyperpigmentation
  • non-melanoma skin cancer
  • pruritus
  • skin blistering/ulceration

Miscellaneous

  • hypersensitivity reactions including anaphylaxis (life-threatening)

Interactions

Drug-Drug interaction

None noted.

Route/Dosage

Topical (Adults) Apply a thin film once daily to affected area.

Availability

Topical gel: 0.016% (equivalent to 0.02% mechlorethamine) in 60 g tubes

Nursing implications

Nursing assessment

  • Assess skin lesions prior to and periodically during therapy.
  • Monitor for skin reactions and secondary skin infections. If skin ulceration, blistering, or moderately-severe or severe dermatitis (marked skin redness with edema, inflammation, itchiness), discontinue therapy. Face, genitalia, anus, and intertriginous skin are increased risk of dermatitis. Restart therapy at decreased frequency of once every 3 days upon improvement. If tolerated for at least 1 wk, increase frequency to every other day for at least 1 wk, then daily if tolerated.
  • Assess for new skin lesions periodically during therapy.

Potential Nursing Diagnoses

Impaired skin integrity (Indications)
Risk for impaired skin integrity (Side Effects)

Implementation

  • Topical: Apply thin film of gel to completely dry skin once daily to affected areas within 30 min of removal from refrigerator; return to refrigerator immediately after use. Apply at least 4 hr before or 30 min after showering or washing. Allow treated areas to dry for 5–10 min after application before covering with clothing. Discard unused gel after 60 days in household trash in a manner that prevents accidental application or ingestion by other, including children and pets.
    • Moisturizers and emollients may be applied to treated areas 2 hr before or 2 hr after application.
    • Do not cover areas of application with occlusive dressing.
    • Avoid fire, flame, and smoking until mechlorethamine topical gel has dried. Gel is alcohol-based and flammable.
    • If oral or nasal mucous membranes are exposed to gel, may cause severe pain, redness, and ulceration. Immediately irrigate with copious amounts of water for at least 15 min and notify health care professional.

Patient/Family Teaching

  • Instruct patient and caregiver on correct technique for application. Advise patients to wash hands thoroughly with soap and water after application. Caregivers must wear disposable nitrile gloves during application and wash hands thoroughly with soap and water after removal of gloves. If accidental skin exposure occurs, caregivers must immediately wash exposed area thoroughly with soap and water for 15 min and remove contaminated clothing. Secondary exposure may cause dermatitis, mucosal injury, and secondary cancers. Instruct patient to read the Patient Information flyer prior to starting therapy and with each Rx refill in case of changes.
  • Encourage patient to assess skin for new skin lesions and notify health care professional if new skin lesions are found.
  • 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.
  • Advise female patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding. May be harmful to fetus.

Evaluation/Desired Outcomes

  • Decrease in lesions in patients with mycosis fungoides-type cutaneous T-cell lymphoma.