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Archive for the ‘Pharmacology’ Category

The Association between Proton Pump Inhibitors and C. Difficile

Posted by medliorator on May 11, 2010

investigators conducted a secondary analysis of prospectively collected data from 101,796 patients who were discharged from a tertiary care medical center during a 5-year period. Acid suppression treatment was the primary exposure of interest, classified by intensity (no acid suppression, histamine2-receptor antagonist [H2RA] treatment, daily PPI use, and PPI use more often than daily).

The risk for nosocomial C difficile infection increased with increasing level of acid suppression. This risk was 0.3% (95% confidence interval [CI], 0.21% – 0.31%) in patients not receiving acid suppressive treatment, 0.6% (95% CI, 0.49% – 0.79%) in those receiving H2RA treatment, 0.9% (95% CI, 0.80% – 0.98%) in those using PPIs daily, and 1.4% (95% CI, 1.15% – 1.71%) in patients using PPIs more often than daily …The odds ratio was 1 for no acid suppression (reference), 1.53 for H2RA treatment (95% CI, 1.12 – 2.10), 1.74 for daily PPI use (95% CI, 1.39 – 2.18), and 2.36 for more frequent PPI use (95% CI, 1.79 – 3.11).

Proton Pump Inhibitor Use Linked to Clostridium Difficile Infection [Medscape]

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Posted in Infectious Disease, Pharmacology | Comments Off on The Association between Proton Pump Inhibitors and C. Difficile

Sipuleucel-T (Provenge), The First FDA-Approved Cancer “Vaccine” – What Every Medical Student Should Know

Posted by medliorator on May 4, 2010

Here are the bare bones facts on Provenge. A basic understanding will help you to stand out when the discussion inevitably comes up.

Drug Name: Sipuleucel-T
Trade Name: Provenge
Trial Name: APC 8015
Manufacturer: Dendreon Corporation
Class: autologous, dendritic cell-based immunotherapy
Indication: hormone-refractory, metastatic prostate cancer
MOA: Induces patient’s own cells to attack prostate cancer.
MOA (detailed): Patient’s immune cells are collected by leukapheresis and sent to a Dendreon facility approximately 3 days prior to treatment. Immune cells are exposed to  recombinant protein (known as PA 2024) that has two, fused components: (1) a prostate cancer associated antigen called prostatic acid phosphatase (PAP) that is expressed in ~95% of prostate cancers and (2) granulocyte-macrophage colony-stimulating factor (GM-CSF), an immune cell activator.  After PA 2024 exposure and processing, the activated cells are infused back into the patient, divided into in three doses two weeks apart.
SFX: f/c, fatigue, back pain, nausea,joint ache, HA.
Cost: $93,000 per treatment
Efficacy: Extends men’s lives by an average of 4.1 months (based upon IMPACT trial D9902B, a 512-patient RTC).
Misconceptions: Provenge differs from traditional vaccines in that it does NOT prevent cancer. “Immunotherapy” is perhaps a better substitute for the term, “vaccine.”

Further reading…
FDA approves prostate cancer “vaccine” [BMJ]
Current status of immunological therapies for prostate cancer [Curr Opin Urol]

Posted in Oncology, Pharmacology, Urology | Comments Off on Sipuleucel-T (Provenge), The First FDA-Approved Cancer “Vaccine” – What Every Medical Student Should Know

Rheumatology Pearls

Posted by medliorator on April 18, 2010

  • A positive ANCA is meaningless if the patient’s illness doesn’t resemble Wegener’s, MPA or RPGN.
  • Septic arthritis—11% mortality.
  • Underappreciated complications of immunosuppressive therapy:
    • Corticosteroids — infectious complications
    • Anti-TNFs & Rituximab — Heb B flare, acute liver failure.
    • Azathiaprine — hypersensitivity syndrome.

Hospital Medicine 2010 April 9 sessions—rheumatology pearls [Notes from Dr. RW]

Posted in Pharmacology, Rheumatology | Comments Off on Rheumatology Pearls

Pharm Friday – Antiplatelet Agents Overview

Posted by medliorator on November 13, 2009

Another home run from our friends at Pharmamotion:

Classification:

antiplatelet_agents_classification

  • ADP Antagonists: thienopyridines act by inhibiting the ADP-dependent pathway of platelet activation. These drugs have no direct effect on prostaglandin metabolism.
    • Ticlopidine …is approved for secondary prevention of thrombotic strokes in patients intolerant of aspirin and for prevention of stent thrombosis in combination with aspirin.  adverse effects [include] neutropenia, thrombocytopenia and thrombotic thrombocytopenic purpura.
    • Clopidogrel is approved for prevention of atherosclerotic events following recent myocardial infarction, stroke or established peripheral arterial disease. It is also approved for use in acute coronary syndromes that are treated with either PCI  or coronary artery bypass grafting. It has a better safety profile than ticlopidine.
  • Aspirin: aspirin inhibits platelet cyclooxygenase, a key enzyme in thromboxane A2 (TXA2) generation. Thromboxane A2 triggers reactions that lead to platelet activation and aggregation, aspirin acts as a potent antiplatelet agent by inhibiting generation of this mediator. These effects last for the life of the anucleate platelet, approximately 7 to 10 days… indicated as prophylaxis against transient ischemic attacks, myocardial infarction and thromboembolic disorders. It is also used for the treatment of acute coronary syndromes
  • Phosphodiesterase inhibitors: Dipyridamole acts as vasodilator and antiplatelet agent. It inhibits adenosine uptake and cyclic GMP phosphodiesterase activity, this decreases platelet aggregability  …it is currently used in combination with aspirin or warfarin in the prophylaxis of thromboembolic disorders.  It is also used in stress testing for myocardial perfusion imaging.
  • GPIIb/IIIa inhibitors: used parenterally in patients with acute coronary syndromes…  the integrin GPIIb/IIIa antagonists prevent cross-linking of platelets… current indications include unstable angina that does not respond to conventional therapy in patients that undergo percutaneous coronary intervention.

Antiplatelet agents: mechanisms of action and general overview [Pharmamotion]

Posted in Cardiology, Pharmacology | 2 Comments »

Generic Versus Branded Drugs: Concerns Amidst Limited Evidence

Posted by medliorator on September 18, 2009

Many physicians have found [the switch to generic drugs] particularly problematic in classes of drugs with a narrow therapeutic range, including antiepileptics, psychotropics, antiarrhythmics, and anticoagulants.

although the generic’s mean maximal concentration and area under the concentration-time curve are typically within a few percentage points of the original’s — typically about 4% — the 90% confidence interval for those means can be 20% below or 25% above the branded drug’s mean.

much of the current evidence of problems with generic antiepileptics is anecdotal, or comes from retrospective or case-control studies — not randomized controlled trials.  But all of those studies have come to similar conclusions.

Two retrospective studies published last year in Neurology found that patients who had events like break-through seizures were much more likely to have been switched from a branded product to a generic… “Brand-to-generic seems to be the biggest issue,” Meador said. “But generic-to-generic seems to confer some risk as well.”

some non-SSRI antidepressants aren’t so forgiving, said Jeffrey Lieberman, MD, a psychiatrist at Columbia University in New York City.  He mentioned the tricyclic drug nortriptyline and bupropion (Wellbutrin) as more susceptible than most antidepressants to dosage variations.

Generics versus Brands: How It Plays Out in Practice [Medpage Today]

Posted in Neuro, Pharmacology | Comments Off on Generic Versus Branded Drugs: Concerns Amidst Limited Evidence

Serotonin Receptor Antagonists

Posted by medliorator on September 11, 2009

ondansetron

All 5-HT3 antagonists are identified by the suffix -setron

The following are  5-HT3  antagonists serum half- lives:

  • Dolasetron (Anzemet): 7-9 hours.
  • Granisetron (Kytril, generic) 9-11 hours.
  • Ondansetron (Zofran, generic): 3.9 hours.
  • Palonosetron (Aloxi): 40 hours.

At equivalent doses for the prevention of acute emesis, 5-HT3 serotonin receptor antagonists have equivalent safety and efficacy and can be used interchangeably… their clinical use is limited to situations that produce vagal stimulation (eg. surgery) and chemotherapy

5-HT activates 5-HT3 receptors on extrinsic intestinal vagal and spinal afferent nerves. These afferent fibers have projections to the  nucleus tractus solitarius (NTS) and the area postrema (AP).

5HT3 antagonists are superior to metoclopramide, droperidol, and dimenhydrinate in the pharmacologic prophylaxis of postoperative nausea and vomiting. Recently, the FDA added a boxed warning to metoclopramide because of an increased risk of tardive dyskinesia

According to experimental data, these agents have shown to induce minor electrocardiographic changes. It is recommended not to administer dolasetron to patients with prolonged QT or with drugs that may prolong the QT interval.

Serotonin 5-HT3-receptor antagonists: pharmacokinetics, MOA, indications and adverse effects [Pharmamotion]

Posted in Pharmacology | Comments Off on Serotonin Receptor Antagonists

Lipid Lowering Agent: Crash Course Podcost

Posted by medliorator on August 8, 2009

The Science of Pharmacy offers a 7 minute review of lipid lowering agents. hosted by a registered pharmacist.  This is a worthwhile and efficient review of very common drugs.


Lipid-Lowering AgentsThe top video clips of the week are here

Posted in Pharmacology | Comments Off on Lipid Lowering Agent: Crash Course Podcost

Saxagliptin Approved (DPP4 inhibitor)

Posted by medliorator on August 3, 2009

Tablets

[Saxagliptin] which will be sold under the brand name Onglyza, is in a relatively new class, called DPP-4 inhibitors, that can be taken along with older diabetes drugs.

Until now, Merck’s Januvia has been the only drug in the class on the market in this country.

Saxagliptin Approval: Finally, Competition for Merck’s Januvia [WSJ Health Blog

Posted in News, Pharmacology | Comments Off on Saxagliptin Approved (DPP4 inhibitor)

Treating Swine Flu

Posted by medliorator on April 26, 2009

Can the swine flu be treated with antiviral drugs?
Like some garden-variety flu, this swine flu is resistant to two drugs known as amantadine and rimantadine… CDC says Tamiflu and Relenza work against this strain of swine flu, the WSJ reports.

Does the flu vaccine protect against the swine flu?
The CDC reported earlier this week that the seasonal flu vaccine “might not” provide protection against the flu. The agency says it has created a “seed vaccine” specifically tailored to this swine flu. That could be used to manufacture a targeted vaccine if officials deem it necessary to do so.

Health Blog Q&A: Swine Flu in the U.S. and Mexico [WSJ]

Posted in News, Pharmacology | Comments Off on Treating Swine Flu

Midwives and Prescriptions

Posted by medliorator on April 26, 2009

The Pennsylvania Board of Nursing has published regulations implementing a 2007 law which gives nurse midwives the authority to prescribe, administer, and dispense drugs pursuant to collaborative agreement with a physician. The law and regulations also apply to medical devices, immunizing agents, and laboratory tests.  In order to obtain prescriptive authority, nurse midwives must hold a master’s degree or equivalent, have national certification, and complete at least 45 hours of advanced pharmacology coursework and 16 hours of continuing education in pharmacology every two years.

Pennsylvania Gives Nurse Midwives Authority to Prescribe [Physician Law]

Posted in News, Pharmacology | Comments Off on Midwives and Prescriptions