Male sexual problems
There are three big ones are premature ejaculation, delayed ejaculation and erectile dysfunction.
Premature ejaculation
Causes: anxiety and relationship problems, iatrogenic (amphetamine, cocaine, dopaminergics), prostatitis, MS, peripheral neuropathy.
Management: condoms, more sex, squeezing tip of penis, stop-go method, SSRIs, sildenafil (can cause the problem in others), anaesthetic creams, psychosexual therapy.
Delayed ejaculation
Causes: anxiety and relationship problems, masturbation in a certain way becoming the only arousal method, neuro problems, diabetes, prostate problems, hypertension, surgery, trauma, SSRIs, antihypertensives.
Treatments: urological referral, psychosexual therapy.
Erectile dysfunction
Causes: vascular, neurological (central or peripheral, smoking, trauma, endocrine (hypogonadism, hyperprolactinaemia, thyroid disease, Cushing's disease), drugs (antihypertensives, beta blockers, diuretics, antidepressants, antipsychotics, hormonal agents, anticonvulsants, antihistamines, illicit drugs, H2 agonist (ranitidine, cimetidine)). Lifestyle stuff, relationship issues - all that jazz.
Treatment: there are loads. Deal with lifestyle/relationship stuff; treat any abnormality (like thyroid storm); give Viagra (sildenafil) or some equivalent.