Pharmacologic: 5-HT3 antagonists
Prevention of nausea and vomiting associated with emetogenic chemotherapy. Prevention and treatment of postoperative nausea/vomiting.
Blocks the effects of serotonin at receptor sites (selective antagonist) located in vagal nerve terminals and in the chemoreceptor trigger zone in the CNS. Therapeutic Effects: Decreased incidence and severity of nausea/vomiting associated with emetogenic chemotherapy or surgery.
Adverse Reactions/Side Effects
CNS: headache (increased in cancer patients), dizziness, fatigue, syncope. CV: bradycardia, ECG changes, hypertension, hypotension, tachycardia. GI: diarrhea, dyspepsia. GU: oliguria. Derm: pruritus. Misc: chills, fever, pain.
PHYSICAL THERAPY IMPLICATIONS
Examination and Evaluation
Monitor improvements in GI symptoms (nausea, vomiting) to help document whether drug therapy is successful.
Assess heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Report any rhythm disturbances or symptoms of increased arrhythmias, including palpitations, chest discomfort, shortness of breath, fainting, and fatigue/weakness.
Assess blood pressure (BP) and compare to normal values (See Appendix F). Report changes in BP, either a problematic decrease in BP (hypotension) or a sustained increase in BP (hypertension).
Assess any unexplained or unusual pain to rule out musculoskeletal pathology; that is, try to determine if pain is drug-induced rather than caused by anatomic or biomechanical problems.
Assess dizziness or syncope that affects gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.
Because of the risk of arrhythmias and abnormal BP responses, use caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently (BP, heart rate, fatigue levels), and terminate exercise immediately if any untoward responses occur (See Appendix L).
Instruct patient to report bothersome or prolonged side effects, including headache, itching skin, problems with urination, chills, fever, or GI effects (diarrhea, indigestion).
Absorption: Well absorbed but rapidly metabolized to hydrodolasetron, the active metabolite.
Metabolism and Excretion: 61% of hydrodolasetron is excreted unchanged by the kidneys.
Half-life: Hydrodolasetron—8.1 hr (shorter in children).
TIME/ACTION PROFILE (antiemetic effect)
|ROUTE ||ONSET ||PEAK ||DURATION |
|PO ||unknown ||1–2 hr ||up to 24 hr |
|IV ||unknown ||15–30 min ||up to 24 hr |
Contraindicated in: Hypersensitivity.
Use Cautiously in: Patients with risk factors for prolongation of cardiac conduction intervals (hypokalemia, hypomagnesemia, ...