Hi Thanks for choosing HCM for your query. I have gone through the problems described in your question. I am of the opinion that the recurrent dizziness spells are mainly due to Tamsulosin. A fall in BP when you change your position from sitting or sleeping to standing occurs (postural hypotension) due to pooling of blood in the periphery (legs). As a result of hypotension you get headache due to increase heart rate a compensatory mechanism. This can be minimized or prevented by taking the dose at bed time. Finasteride is unlikely to cause the postural hypotension and hence dizziness or headache. In view of your appointment in two weeks time take Tamsulosin at bed time, its sudden stoppage may cause increase in BP and the urinary symptoms urgency, frequency may get exaggerated. I hope your doubts are clarified. A feed back is appreciated if you are convinced. Take care.