Vomiting pharmacokinetics

Mechanism of Action Apiperazine derivative that competes with histamine for receptor sites in the GI tract, blood vessels, and respiratory tract. May exert CNS depressant activity in subcortical areas. Diminishes vestibular stimulation and depresses labyrinthine function. Therapeutic Effect Produces anxiolytic, anticholinergic, antihista-minic, and analgesic effects relaxes skeletal muscle controls nausea and vomiting. Pharmacokinetics ... 

Mechanism of Action A phenothiazine that acts as an antihistamine, antiemetic, and CNS-antipsychotiC typical hypnotic. As an antihistamine, inhibits histamine at histamine receptor sites. As an antiemetic, diminishes vestibular stimulation, depresses labyrinthine function, and acts on the chemoreceptor trigger zone. As a sedative-hypnotic, produces CNS depression by decreasing stimulation to the brainstem reticular formation. Therapeutic Effect Prevents allergic responses mediated by histamine, such as rhinitis, urticaria, and pruritus. Prevents and relieves nausea and vomiting. Pharmacokinetics ... 

Mechanism of Action An anticholinergic that acts at the chemoreceptor trigger zone in the medulla oblongata. Therapeutic Effect Relieves nausea and vomiting. Pharmacokinetics ... 

Vinblastine is another vesicant vinca alkaloid that causes myelo-suppression and less neurotoxicity than vincristine. The pharmacokinetics of vinblastine are best described by a three-compartment model, with an a half-life of 25 minutes, a 3 half-life of 53 minutes, and a terminal half-life of 19 to 25 hours.12 Vinblastine has shown activity in the treatment of bladder, breast, and kidney cancer, as well as some lymphomas. The doses of vinblastine tend to be higher on a milligram per meter squared basis than vincristine. Nausea and vomiting are minimal with vinblastine. Other side effects include mild alopecia, rash, photosensitivity, and stomatitis. 

The vesicant vinorelbine is structurally similar to vincristine and may cause many of the same side effects as vincristine. While this vesicant is administered intravenously over 6 to 10 minutes, patients should be counseled about neuropathy, ileus, and myelosuppression. The pharmacokinetics of vinorelbine are best described by a three-compartment model, with an a half-life of 2 to 6 minutes, a 3 half-life of 1.9 hours, and a y half-life of 40 hours. Vinorelbine has shown efficacy in the treatment of breast cancer and non-small cell lung cancer. Additional side effects include myelosuppression, paresthesias, and mild nausea and vomiting. 

Teniposide, a topoisomerase II inhibitor, is administered as an infusion over 30 to 60 minutes to prevent hypotension. The pharmacokinetics are described by a three-compartment model, with an a half-life of 0.75 hours, a (5 half-life of 4 hours, and a terminal half-life of 20 hours. Considerable variability in clearance of teniposide in children has been reported.17 Teniposide has shown activity in the treatment of acute lymphocytic leukemia, neuroblastoma, and non-Hodgkin s lymphoma. Side effects include myelosuppression, nausea, vomiting, mucositis, and venous irritation. Hypersensitivity reactions may be life-threatening. 

Idarubicin inhibits both DNA and RNA polymerase, as well as topoisomerase II. The pharmacokinetics of idarubicin can best be described by a three-compartment model, with an a half-life of 13 minutes, a (3 half-life of 2.4 hours, and a terminal half-life of 16 hours.22 Idarubicin is metabolized to an active metabolite, idarubicinol, which has a half-life of 41 to 69 hours. Idarubicin and idarubicinol are eliminated by the liver and through the bile. Idarubicin has shown clinical activity in the treatment of acute leukemias, chronic myelogenous leukemia, and myelodysplastic syndromes. Idarubicin causes cardiomyopathy at cumulative doses of greater than 150 mg/m2 and produces cumulative cardiotoxic effects with other anthracyclines. Idarubicin is a vesicant and causes red-orange urine, mucositis, mild to moderate nausea and vomiting, and bone marrow suppression. 

This royal-blue-colored drug is an anthracenedione that inhibits DNA topoisomerase II. The pharmacokinetics of mitoxantrone may best be described by a three-compartment model, with an a half-life of 3 to 10 minutes, a 3 half life of 0.3 to 3 hours, and a median terminal half-life of 12 days. Biliary elimination appears to be the primary route of elimination, with less than 10% of the drug eliminated by the kidney.23 Mitoxantrone has shown clinical activity in the treatment of acute leukemias, breast and prostate cancer, and non-Hodgkin s lymphomas. Myelosuppression, mucositis, nausea and vomiting, and cardiac toxicity are side effects of this drug. The total cumulative dose limit is 160 mg/m2 for patients who have not received prior anthracycline or mediastinal radiation. Patients who have received prior doxorubicin or daunorubicin therapy should not receive a cumulative dose greater than 120 mg/m2 of mitoxantrone. Patients should be counseled that their urine will turn a blue-green color. 

Denileukin diftitox is a combination of the active sections of interleukin 2 and diphtheria toxin. It binds to high-affinity interleukin 2 receptors on the cancer cell (and other cells), and the toxin portion of the molecule inhibits protein synthesis to result in cell death. The pharmacokinetics of denileukin diftitox are best described by a two-compartment model, with an a half-life of 2 to 5 minutes and a terminal half-life of 70 to 80 minutes. Denileukin diftitox is used for the treatment of persistent or recurrent cutaneous T-cell lymphoma whose cells express the CD25 receptor. Side effects include vascular leak syndrome, fevers/chills, hypersensitivity reactions, hypotension, anorexia, diarrhea, and nausea and vomiting. 

Cetuximab is a human/mouse antibody that binds to the epidermal growth factor receptor to block its stimulation. The pharmacokinetics of cetuximab demonstrate a volume of distribution that approximates the vascular space and a terminal half-life of 70 to 100 hours. Cetuximab has shown clinical activity in the treatment of colorectal cancer. An acnelike rash may appear on the face and upper torso 1 to 3 weeks after the start of therapy. Other side effects include hypersensitivity reactions, interstitial lung disease, fever, malaise, diarrhea, abdominal pain, and nausea and vomiting. 

Rituximab is a monoclonal antibody to the CD20 receptor expressed on the surface of B lymphocytes the presence of the antibody is determined during flow cytometry of the tumor cells. Cell death results from antibody-dependent cellular cytotoxicity. The pharmacokinetics of rituximab are best described by a two-compartment model, with a terminal half-life of 76 hours after the first infusion and a terminal half-life of 205 hours after the fourth dose.36 Rituximab has shown clinical activity in the treatment of B-cell lymphomas that are CD20+. Side effects include hypersensitivity reactions, hypotension, fevers, chills, rash, headache, and mild nausea and vomiting. 

Pharmacokinetics Mechanism is obscure, but may be mediated through the chemoreceptor trigger zone direct impulses to vomiting center are not inhibited. 

Pharmacokinetics attd Pharmacology. Older macrolides such as erythromycin exhibit relatively low serum concentrations, short in vivo half-hves, highly variable oral absorption, and low oral bioavailability. Improvements in these pharmacokinetic parameters have been accomplished for newer derivatives. The principal side effects of macrolides aie gastrointestinal problems, such as pain, indigestion, diarrhea, nausea, and vomiting. 

Flumazenil is used as a benzodiazepine antagonist in the treatment of poisoning or the reversal of benzodiazepine effects in anesthesia 1,2) or in neonates (3). Guidelines for its use have been summarized (4). The problems in its use are those of dose adjustment, the risks of panic anxiety, seizures, or other signs of excessively rapid benzodiazepine withdrawal, and pharmacokinetic problems due to the short half-life of flumazenil (about 1 hour) compared with the longer half-lives of most benzodiazepines (5). Its use is also commonly associated with vomiting and headache, and rarely with psychosis or sudden cardiac death (SEDA-17,... 

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