granisetron hydrochloride

granisetron hydrochloride

Kytril

Pharmacologic class: 5-hydroxytryptamine₃ antagonist

Therapeutic class: Antiemetic

Pregnancy risk category B

Action

Binds to serotonin receptors in chemoreceptor trigger zone and vagal nerve terminals, blocking serotonin release and controlling nausea and vomiting

Availability

Injection: 1 mg/ml

Oral solution: 2 mg/10 ml in 30-ml bottles

Tablets: 1 mg

⊘Indications and dosages

➣ To prevent nausea and vomiting caused by chemotherapy

Adults and children ages 2 to 16: For I.V. use, 10 mcg/kg I.V. within 30 minutes before chemotherapy. For P.O. use (adults only), 1 mg P.O. b.i.d., with first dose given at least 1 hour before chemotherapy and second dose given 12 hours later on days when chemotherapy is administered; or 2 mg P.O. daily at least 1 hour before chemotherapy.

➣ To prevent nausea and vomiting caused by radiation therapy

Adults: 2 mg P.O. daily within 1 hour of radiation therapy

➣ Acute postoperative nausea and vomiting

Adults: 1 mg I.V. undiluted, administered over 30 seconds

Contraindications

• Hypersensitivity to drug

Precautions

Use cautiously in:
• pregnant or breastfeeding patients
• children younger than age 18 (safety of P.O. use not established)
• children younger than age 2 (safety of I.V. use not established).

Administration

• For I.V. infusion, dilute with 20 to 50 ml of normal saline solution or dextrose 5% in water.
• Infuse I.V. over 5 minutes, starting 30 minutes before chemotherapy.
• For direct I.V. injection, give undiluted over 30 seconds.
• Don't mix I.V. form with other drugs.
• For P.O. use, give first dose 1 hour before chemotherapy and second dose 12 hours after first.

Route	Onset	Peak	Duration
P.O.	Rapid	1 hr	24 hr
I.V.	Rapid	30 min	Up to 24 hr

Adverse reactions

CNS: headache, anxiety, stimulation, weakness, drowsiness, dizziness

CV: hypertension

GI: nausea, vomiting, diarrhea, constipation, abdominal pain

Hematologic: anemia, leukopenia, thrombocytopenia

Skin: alopecia

Other: altered taste, decreased appetite, fever, chills, shivering

Interactions

Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase: increased levels

Electrolytes: altered levels

Hemoglobin, platelets, white blood cells: decreased levels

Drug-herbs. Horehound: enhanced serotonergic effects

Patient monitoring

• Monitor hepatic enzyme levels and CBC with white cell differential.
• Monitor temperature and blood pressure. Have patient use caution when ambulating, to avoid orthostatic hypotension.

Patient teaching

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Advise patient to minimize GI upset by eating frequent, small servings of healthy food.
• Tell patient he'll undergo regular blood testing during therapy.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the tests and herbs mentioned above.