In September 2020, Acella Pharmaceuticals LLC recalled two lots of NP Throid and RLC Labs Inc. recalled all lots of Nature-Throid and WP Thyroid because testing showed they contained less levothyroxine than the labelled amount. In March of this year, Acella recalled certain lots of NP Thyroid with expiration dates into September 2021 for the same reason—the medication was found to have less than 90% of one of the active ingredients. Problems with supply chain and complications caused by the pandemic have resulted in continued shortages months later.
Patients who receive subpotent thyroid medication may experience a variety of hypothyroid symptoms including fatigue, heightened sensitivity to cold, depression, weight gain, dry skin, puffy face, and hair loss. Additionally, heart rate may slow, and cholesterol levels could rise, so failing to refill a prescription or receive a substitute medication could have significant adverse effects.
NP Thyroid, Nature-Throid, and WP Thyroid all contain dessicated porcine thyroid, which contains both levothyroxine (T4) and liothyronine (T3). The most direct substitute is Armour Thyroid, which is also derived from porcine thyroid and contains both T4 and T3, but it tends to be more expensive under many insurance companies' pharmacy plans.
Other options include Synthroid (levothyroxine sodium), which is the most commonly prescribed medication for hypothyroidism, Unithroid, or Levoxyl. A new option is Tirosint, another brand of levothyroxine sodium. Patients prescribed one of the desiccated thyroid tablets, however, may have been switched to their current medication because levothyroxine alone did not fully address their symptoms. Often, physicians will also prescribe liothyronine sodium, Cytomel, or Triostat for these patients.
If your customer has had to switch brands of thyroid medication, they may need to adjust their dosage to obtain the same results. The American Thyroid Association, American Association of Clinical Endocrinologists, and The Endocrine Society all recommend retesting TSH levels after a switch to a new brand, as even small variations in the percentage of the active ingredient in the tablets can make a significant difference.
Regardless of the brand filled, pharmacists should alert their customers that medications for epilepsy, such as carbamazepine and phenytoin sodium, birth control pills, estrogen, testosterone, sertraline, and tyrosine kinase inhibitors used in cancer treatment, may interact with thyroid medications and should not be taken at the same time. Supplements including iron and calcium may reduce absorption and should also not be taken at the same time as a medication that contains levothyroxine. Ideally, the medication should be taken 30 minutes to an hour before breakfast or 3 hours after dinner.
While finding a good substitute and working out the right dosage for a long-prescribed drug can be a nuisance for patients, they should be discouraged from simply discontinuing treatment because of the high risk of recurring signs and symptoms of hypothyroidism.
The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.
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