Drug Safety Oversight Board Meeting, November 18, 2010
The Executive Director updated the Drug Safety Oversight Board (DSB or Board) on Drug Safety Communications posted and in development since the October 21, 2010 meeting. The following is a list of the posted risk communications:
Drug Safety Communications Posted since the October 21, 2010 DSB meeting:
- October 21, 2010: Invirase (saquinavir) labels now contain updated risk information on abnormal heart rhythms: FDA issued a DSC notifying the public that new risk information has been added to the label of the antiviral drug Invirase (saquinavir), describing a potential change in the electrical activity of the heart when Invirase is used with another antiviral medication, Norvir (ritonavir). The PR or QT interval can be prolonged, leading to potential arrhythmias.
The DSB discussed three topics:
1. Update on Tablet Splitting/Scoring
2. Benzocaine and Methemoglobinemia
3. A draft Drug Safety Communication (DSC) related to a prescription product used to treat cough
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Update on Tablet Splitting/Scoring
Tablet splitting refers to cutting a tablet, usually in half, so as to provide flexibility in dosing of a drug or as a cost-saving measure. For example, some drugs are monitored with blood tests that allow the dosage to be adjusted to achieve a therapeutic goal. In addition, in some instances, a tablet with double the amount of drug costs less than double the price of two smaller tablets. In this instance, cutting the tablet in half can save on medication cost. Tablets often have a line or “score” in the tablet to facilitate splitting but often the tablets do not split into equal segments. A tablet splitting tool can be used as an aid but also does not ensure uniform segments on splitting.
The Board invited a guest expert from the US Pharmacopoeia (USP), Dr. Anthony DeStefano, Vice President of the General Chapters at the USP. Dr. DeStefano spoke about the history of the USP and its current collaboration with FDA on the tablet scoring and splitting issue.
The Board discussed the following:
- An overview of the practice of tablet splitting and tablet scoring
- Progress on a draft guidance regarding tablet scoring
- Perspectives about tablet scoring from the US Pharmacopoeia Input from the federal partners on the DSB regarding their experience with tablet splitting in patient care settings
Benzocaine and Methemoglobinemia
Methemoglobinemia a disorder characterized by the presence of a higher than normal level of methemoglobin (metHgb) in the blood. MetHgb cannot carry oxygen and hinders the unloading of oxygen to tissues. Methemoglobinemia can be congenital or acquired (e.g. induced by drugs or chemicals). FDA has received reports of drug-induced methemoglobinemia associated with benzocaine products used for topical anesthesia.
The Board discussed the following:
- An overview of the safety issue with benzocaine products used for topical anesthesia.
- Previous actions to address this issue
- MedWatch reports received by FDA regarding benzocaine products used for topical anesthesia.
- Scope of the current safety issue
- Possible actions to help address the safety issue
Draft Drug Safety Communication
The Board discussed a draft DSC involving a prescription product approved for the symptomatic treatment of cough in patients over 10 years of age. The product has been rarely associated with death following accidental ingestion by children under 10 years of age. The Board evaluated whether the draft DSC effectively communicated, without alarm, the important messages to consumers and healthcare professionals about proper use of the product, keeping it away from children, and disposing of leftover medication.