Up Close and Personal
There has been a lot of talk recently about pharmacogenomics and personalized medicine. Pharmaco-genomics—the way an individual responds to a medication—includes both positive and negative reactions, and how individual genetic differences affect drug response. It also examines the inherited variations in genes that dictate drug response and explores how these variations can be used to predict what type of response a patient will have to a particular drug, whether that is a good response, a bad response, or no response at all.1
In the race to catalog all the different gene variations, variations known as single nucleotide polymorphisms (SNPs, or “snips”) are used diagnostically to predict a patient’s response to a drug. In the future, pharmaceutical companies could use pharmacogenomics to predict which patients will have a negative response to a particular drug in clinical trials and, therefore, not study the medication in those patients.2 In essence, it would be a way to “streamline” therapy to those in most need of it or for those who likely will have a positive response with minimal adverse events.
- Levetiracetam tablets (Keppra)9
New Drugs, Indications & Dosage Forms
Amiodarone hydrochloride injections (Nexterone) have been approved by the FDA as a novel, co-solvent-free formulation of amiodarone intravenous (IV).10 It is indicated for treating and prophylaxing frequently recurring ventricular fibrillation and hemodynamically unstable ventricular tachycardia in patients that are refractory to other therapy. It was developed to overcome limitations (e.g., fatal gasping syndrome) associated with the use of the co-solvents polysorbate 80 and benzyl alcohol while preserving its beneficial antiarrhythmic effects. It will be available in ready-to-use pre-mixed bags and pre-filled syringes.
Nicardipine hydrochloride IV (Cardene IV) is available in a double concentration (40 mg or 0.2-mg/mL) in ready-to-use 200 mL bags of 5% dextrose or 0.83% sodium chloride.11
Prasugrel (Effient, Eli Lilly/Daiichi Sankyo) was reviewed for FDA approval on Feb. 3 by the Cardiovascular and Renal Drugs Advisory Committee (CDRAC).12 The committee voted unanimously in favor of prasugrel as a treatment for acute coronary syndrome that is managed with percutaneous coronary intervention. CDRAC members advised against using prasugrel in patients with a history of stroke and for patients undergoing open-heart surgery. The CDRAC did not advise limiting its use in patients younger than 75. The committee did express caution regarding prasugrel use in patients weighing less than 130 pounds (59 kilograms) because these patients might be at a higher risk of bleeding. The CDRAC also noted higher cancer rates among prasugrel users compared with clopidogrel users, and stated the drug may have to carry warnings about this risk. The FDA has not set a date for its final decision.13
Ropinirole XL (Requip XL) is available in a new, 12-mg tablet for once-daily dosing. Other available tablet strengths include 2, 4, and 8 mg.14
Venlafaxine extended-release tablets (Osmotica Pharma) have been approved by the FDA as a “new drug,” though they are bioequivalent to Effexor XR capsules. However, they are not therapeutically interchangeable, due to the different dosage forms of these products (tablet versus capsule).15 In states with a therapeutic substitution law, pharmacists cannot automatically substitute venlafaxine extended-release tablets for Effexor XR without a prescriber’s authorization. It is important to note and tell patients that venlafaxine extended-release tablets travel through the gastrointestinal tract and are eliminated in the feces as a “ghost tablet” (i.e., a core tablet with no drug), so if they see a tablet in their stool, they shouldn’t worry that they didn’t absorb the medication.
By pre-screening patients, clinical trials could be smaller, faster, and less costly. The capability to pre-assess whether a patient will benefit from a particular medication before it is prescribed is a major advantage when it comes to medication use. It also might increase a prescriber’s confidence before starting a patient on a medication, and it might improve a patient’s confidence in taking the medication, which could increase medication adherence and lead to better patient outcomes.
