Warning about clozapine and constipation

This column reviews details on recent recalls, warnings, and approvals.

Recalls, warnings, and alerts

A class I recall of the MiniMed 600 Series Insulin Pumps by Medtronic due to incorrect insulin dosing. The issue is due to a missing or broken retainer ring, which helps to lock the insulin cartridge into place in the pump's reservoir compartment. If the cartridge is not locked firmly into place, under- or over-delivery of insulin may occur. The manufacturer has received a total of 26,421 complaints and is aware of 2,175 injuries and one death. A total of 322,005 affected devices were distributed at various times between September 2016 and October 2019.

A strengthened warning that constipation caused by clozapine can uncommonly progress to serious bowel complications. The schizophrenia medicine affects bowel function in a majority of patients, and constipation can lead to hospitalization or death if not diagnosed and treated quickly. Clinicians should evaluate bowel function before starting a patient on clozapine (Clozaril, Fazaclo ODT, Versacloz, generics), should avoid co-prescribing the drug with other anticholinergic medicines that can cause gastrointestinal hypomotility, should frequently advise patients on the need to stay hydrated to prevent constipation, and should ask patients about bowel movement frequency and quality throughout treatment, the FDA recommended.

A class I recall of Comfort Flo Humidification Systems by Teleflex Medical due to the risk for water to enter the airway. There have been 102 complaints and eight injuries, including low oxygen in the blood and bradycardia. No deaths have been reported. The recall includes 398,320 devices distributed from Oct. 1, 2014, to Oct. 31, 2019.

A class I recall of Carestation 600 Series Anesthesia Systems by GE Healthcare due to the potential loss of mechanical ventilation. The issue is caused by a loose cable connection inside the system. If mechanical ventilation stops working, the system will emit a high-priority audio and visual alarm. No injuries or deaths have been reported. A total of 3,599 devices distributed from August 2018 to July 2019 are affected.

A class I recall of specific lots of NC Trek RX and NC Traveler RX Coronary Dilatation Catheters with balloon diameters of 4.0 mm, 4.5 mm, and 5.0 mm by Abbott Vascular due to failure of balloon deflation. This issue is due to weaker material close to the balloon bond as a result of excessive exposure to heat during manufacturing. There have been 13 complaints and one death related to this issue. The recall includes 13,891 devices distributed from August 2019 to January 2020.

A class I recall of the TM-317 PneumoDart-Pneumothorax Needle by TyTek Medical due to the risk of blocked needles. The blockage is caused by the presence of adhesive from the assembly process. There has been one complaint, but no injuries or deaths have been reported. The recall includes 920 devices distributed from June 3 to Sept. 17, 2019.

A class I recall of Carescape Respiratory Modules and Airway Gas Option by GE Healthcare due to incorrect oxygen values. There have been no reported injuries or deaths. The recall includes 165 devices distributed from June 7 to Aug. 16, 2019.

A class I recall of Stellar 100 and 150 Noninvasive and Invasive Ventilators by ResMed because the sound alarm may fail to work. There has been one reported death due to this issue. The recall includes 69 devices distributed from April 2016 to November 2017.

A recall of 171 units of the King Vision Video Laryngoscope Adapter (size 1/2) by King Systems due to exhibiting a reversed image. Affected products were distributed from Aug. 2 to Oct. 25, 2019.


A request that lorcaserin be withdrawn from the U.S. market by manufacturer Eisai due to concerns about cancer risk. The manufacturer has submitted a request to voluntarily withdraw the weight-loss drug. A postmarket trial found that more patients taking lorcaserin (n=462; 7.7%) were diagnosed with cancer compared to those taking placebo (n=423; 7.1%). A range of cancer types were reported, with several (including pancreatic, colorectal, and lung) occurring more frequently in the lorcaserin group. Clinicians should stop prescribing and dispensing lorcaserin to patients and should discuss alternative weight-loss medicines or strategies, the FDA said. Special screening for patients who have taken lorcaserin is not recommended.

No sample of metformin tested by the FDA has exceeded the acceptable daily intake for N-nitrosodimethylamine (NDMA), a probable carcinogen. Laboratory results showed that NDMA levels in metformin products range from not detectable to low, similar to those in foods like grilled or smoked meats. The FDA has not recommended metformin recalls in the U.S.


Diclofenac and two allergy eye drops, formerly available only by prescription, for over-the-counter (OTC) use. Through a process called a prescription-to-OTC switch, the FDA approved nonprescription use of diclofenac sodium topical gel, 1% (Voltaren Arthritis Pain), for the temporary relief of arthritis pain, as well as olopatadine hydrochloride ophthalmic solution/drops, 0.1% (Pataday Twice Daily Relief) and 0.2% (Pataday Once Daily Relief) for the temporary relief of itchy and red eyes due to pollen, ragweed, grass, animal hair, or dander. All three products will no longer be available as prescription drugs.

Marketing of software to assist in the acquisition of echocardiography images. The software, called Caption Guidance, is an accessory to compatible diagnostic ultrasound systems and uses artificial intelligence (AI) to help the user capture images of a patient's heart that are of acceptable diagnostic quality. The interactive AI user interface provides prescriptive guidance on maneuvering the ultrasound probe and real-time feedback on potential image quality. It can auto-capture video clips and automatically saves the best video clip acquired from a particular view. A cardiologist then conducts final review and assessment of the images and videos for patient evaluation. The software is indicated for use in 2D transthoracic echocardiography for adult patients, specifically in the acquisition of standard views of the heart from different angles.

Marketing of the first genetic test to aid in the diagnosis of fragile X syndrome (FXS), the most common known cause of inherited developmental delay and intellectual disability. The AmplideX Fragile X Dx and Carrier Screen Kit is also intended for use in adults who may be carriers of genetic alterations in the FMR1 gene associated with the syndrome. The test can also be used to aid in the diagnosis of fragile X-associated disorders, including fragile X-associated tremor/ataxia syndrome, which typically occurs in adults older than age 50 years, and fragile X-associated primary ovarian insufficiency. The test should be used along with the evaluation of a patient's family history and clinical signs and symptoms.

First-time generic approvals

Albuterol sulfate inhalation aerosol (90 µg/actuation) to treat or prevent bronchospasm in patients ages 4 years and older with reversible obstructive airway disease and to prevent exercise-induced bronchospasm in this age group. (Brand name: ProAir HFA)

Hydrocodone bitartrate extended-release capsules (10, 15, 20, 30, 40, and 50 mg) to manage pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate. (Brand name: Zohydro ER)

Note: The FDA states that drugs are not always commercially available immediately after approval.