Primary hypothyroidism is usually the result of Hashimoto's thyroiditis, thyroidectomy for hyperthyroidism, goiter or cancer, or radioactive iodine therapy for hyperthyroidism.

Since the last Medical Letter article on this subject (volume 25, page 54, 1983), transplantation of various organs has become routine, but problems of supply and demand have persisted. The United Network for Organ Sharing (UNOS), which has contracted with the federal government to maintain a list of patients waiting for transplantation and a registry of patients who have received an organ, reports that 18,251 patients received an organ transplant in 1994, and as of June 1995 more than 40,000 patients were waiting for one.

Bendamustine HCl (Treanda - Cephalon), an unusual DNA-alkylating agent that has been used in Europe for many years to treat lymphoma, has now been approved by the FDA for treatment of chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphoma (NHL).

Infertility occurs in about 15% of couples. About one-third of cases are due to problems with ovulation or other female factors, another third are due to a male infertility factor, and the remaining third are unexplained. In older women, unexplained infertility is probably caused by diminished quality and quantity of oocytes. The first approach to treatment of female-factor infertility generally is the use of drugs that stimulate oocyte production.

The FDA has approved the sGC stimulator riociguat (rye" oh sig' ue at; Adempas – Bayer) for oral treatment of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) following surgery or when surgery is not an option. It is the first drug to be approved for treatment of CTEPH.

The FDA has approved isavuconazonium sulfate (Cresemba – Astellas) for intravenous and oral treatment of invasive aspergillosis and invasive mucormycosis in adults. Isavuconazonium sulfate is a prodrug of isavuconazole, a broad-spectrum triazole antifungal.

The FDA has approved the monoamine oxidase type B (MAO-B) inhibitor safinamide (Xadago – US Worldmeds) as an adjunct to levodopa/carbidopa for management of "off" episodes in patients with Parkinson’s disease (PD). It is the first reversible MAO-B inhibitor to be approved for this indication. Selegiline (Eldepryl, and others) and rasagiline (Azilect, and generics), two irreversible MAO-B inhibitors, have been used alone and as adjuncts to levodopa/carbidopa for many years. Safinamide is not approved for use as monotherapy.

The FDA has approved letermovir (Prevymis – Merck), a cytomegalovirus (CMV) DNA terminase complex inhibitor, for prophylaxis of CMV infection and disease in CMV-seropositive adult recipients of an allogeneic hematopoietic cell transplant (HCT). Letermovir is the first CMV DNA terminase complex inhibitor to be approved in the US and the only drug specifically indicated for CMV prophylaxis in HCT patients. It is not approved for treatment of CMV infection.

Brolucizumab-dbll (Beovu — Novartis), a vascular endothelial growth factor (VEGF) inhibitor, has been approved by the FDA as an intravitreal injection for treatment of neovascular (wet) age-related macular degeneration (AMD). It is the fourth VEGF inhibitor to be approved in the US for this indication; bevacizumab (Avastin, and others), a VEGF inhibitor FDA-approved for treatment of breast cancer and other malignancies, has been used off-label for this indication for years.

The FDA has approved an orally disintegrating tablet (ODT) formulation of rimegepant (Nurtec ODT – Biohaven), a small-molecule calcitonin gene-related peptide (CGRP) receptor antagonist ("gepant"), for acute treatment of migraine with or without aura in adults. Rimegepant is the second oral gepant to become available in the US; ubrogepant (Ubrelvy), which is approved for the same indication, was the first. Four parenteral CGRP antagonists, erenumab (Aimovig), fremanezumab (Ajovy), galcanezumab (Emgality), and eptinezumab (Vyepti), are approved for prevention of...