THST appears justified in ThyrCa patients following initial therapy. As most primary studies were imperfect, future research will better define the effect of THST upon ThyrCa clinical outcomes.

Decreased absorption of levothyroxine when given with calcium carbonate may be particularly pronounced in patients with preexisting malabsorption disorders. Once recognized, a change in drug administration schedule usually minimizes or eliminates this interaction.

A 22-year-old man with hypogonadotropic hypogonadism was receiving monthly intramuscular injections of testosterone replacement therapy. The patient refused to self-administer the injections because of discomfort, so the therapy was switched to testosterone patches. He experienced a pruritic, macular, erythematous rash underneath the reservoir area of two different transdermal formulations, which did not improve after pretreatment with topical corticosteroids. Eventually, he tolerated application of a testosterone gel and his serum testosterone levels returned to normal after 1 month of therapy. Commercially available and investigational testosterone products and therapeutic monitoring guidelines for androgen replacement are reviewed.