As you can see, K52.9 is like a mystery box. It covers many possible causes
Neuropsychopharmacol 28 , 683693 (2003)
Drug-induced gynaecomastia typically arises through one or more of the following mechanisms: Increased oestrogen activity either by raising oestrogen levels or mimicking oestrogen at receptor level Reduced androgen activity by blocking testosterone production or its action at tissue level Elevated prolactin levels which can stimulate breast tissue development (most commonly associated with antipsychotic medicines) Altered sex hormone-binding globulin (SHBG) concentrations changing the balance of free testosterone to free oestrogen Medicines most commonly implicated include spironolactone, cimetidine, anti-androgens, certain antipsychotics, and some chemotherapy agents
10.3164/jcbn.D-11-00017 J
Mondello et al., 2014), and PSP (Wang et al., 2012)
Qsymia works through central nervous system stimulation (phentermine) and neurotransmitter modulation (topiramate)